Contributions to Terrestrial Magnetism.--No. VIII

XVIII. Contributions to Terrestrial Magnetism.—No. VIII. By Lieut.-Colonel Edward Sabine, R.A., For. Sec. R.S. Received June 15.—Read June 18, 1846. Containing a Magnetic Survey of the Southern Hemisphere between the Meridians of 0° and 125° East, and Parallels of —20° and —70°. The Antarctic Expedition, under Captain Sir James Clark Ross, R.N., has furnished the materials for maps of the three magnetic elements in the high latitudes of the southern hemisphere for nearly two-thirds of its circumference. The first and second portions of the results, comprising between the meridians of 125° and 300°, have already been communicated to the Royal Society, and are contained in the Vth and VIth Numbers of these Contributions*; a third portion, comprehending between the meridians of 300° and 360°, is in preparation and will shortly be laid before the Society. In order to complete the magnetic survey of the high latitudes of the southern hemisphere as far as they are accessible, there remained the portion between the longitudes of 0° and 125°, or thereabouts. The tracks of vessels in the employ of the enterprising merchants, the Messrs. Enderby, had shown that no difficulties of serious importance obstructed the navigation of the ocean in the vicinity of the Antarctic Circle between the meridians specified: and there appeared to be little reason to doubt, that a vessel, despatched from the Cape of Good Hope, might accomplish this remaining portion of the survey in a single season, without encountering any particular risk. Lieut. Clerk, of the Royal Artillery, had been attached by Lord Vivian, Master-General of the Ordnance, to the Magnetic Observatory at the Cape of Good Hope, with the express view of being engaged in a magnetic survey, either of the colony itself, or of such portion of the globe as might be conveniently accessible from it; and on his passage from England to the Cape had had an opportunity of practising with the instruments employed in a magnetic survey conducted on the ocean. The completion of the survey of the high latitudes appeared the most important service which Lieut. Clerk could render to magnetical science; and on its being proposed to him, he most readily undertook it. In June 1844 the subject was brought under the consideration of the Committee of Physics of the Royal Society, by a letter from myself to Sir John F. W. Herschel, Bart., Chairman of the Committee, accompanied by one addressed by Sir John Herschel to the Committee, expressing his earnest hope that the measures suggested for the * Philosophical Transactions, 1843, Art. X., and 1844, Art. VII. completion of the survey might receive the attention which they appeared to him to merit. These letters were submitted by the Committee to the Council of the Royal Society, with a recommendation that an application should be made by the President and Council to the Lords Commissioners of the Admiralty, to authorize the completion of the southern survey in the manner suggested. The Board of Admiralty having been pleased to accede to this request, the "Pagoda," a bark of 360 tons, was hired at the Cape of Good Hope by the Admiral commanding on the station, and was fitted for a voyage of some months duration, receiving a complement of four officers and thirty-eight seamen from the flag-ship. Lieut. T. E. L. Moore, of the Royal Navy, who had been one of the officers of Her Majesty's ship Terror in the Antarctic Expedition, and was consequently accustomed to the navigation of the high latitudes, as well as practised in magnetic observations, (having taken a very prominent share in those of Her Majesty's ship Terror, recorded in Nos. V. and VI. of these Contributions,) was selected to command the Pagoda, and instructed to cooperate with Lieut. Clerk, and to give him every assistance and support in the execution of the service on which they were jointly employed. At the time of his appointment, Lieut. Moore was serving in the Caledonia at Lisbon, and some little delay occurred in his recall, and also in his subsequent departure from England, in consequence of which he did not join the Pagoda at the Cape until the 4th of January, when she had been some days ready for sea. It may be useful to officers desirous of making magnetic observations on board ship, to be acquainted with the precautions which, at the period in question, were deemed desirable for the employment of magnetic instruments on board ship under the most advantageous conditions, and for eliminating the disturbing effects of the ship's iron: a copy of the instructions with which Lieut. Clerk was furnished is therefore subjoined: Instructions for Lieut. H. Clerk, R.A., on points connected with the Magnetic Observations on Board Ship. "1. Influence of the Ship's Iron.—Before the ship is fitted, you had better select, in concert with the naval officer appointed to command her, suitable positions for the standard compass and for your Fox. They should both be on the midship line of the ship; the standard compass sufficiently high to see well over the bulwarks when taking azimuths: the Fox lower for the sake of steadiness: it is generally found convenient to use the Fox a few feet in front of the standard. When the positions have been chosen, have any iron that may be near them removed, (as far as can conveniently be done,) and do not let any fresh iron be placed within at least six feet of either of them. "When the ship is perfectly ready for sea, take a day for the determination of the effect of the ship's iron on the standard compass. You are already acquainted with the usual process of doing this, and are furnished with the printed instructions issued by the Admiralty; therefore I do not enter into further details on this point, except to suggest that you should be particularly careful that the ship's boats, davits, &c. are all in the positions they will occupy at sea; and that it will be quite sufficient for your purpose that the deviation should be tried on the sixteen principal points of the compass, instead of on thirty-two, as is sometimes done. "2. Whilst engaged with the standard compass, have a second compass, of which the compass error (meaning thereby the index error) is known, placed in the gimball table of your Fox, and observe generally (by means of the lubber-line) whether the effect of the ship's iron is nearly the same at the two positions, viz. at the position of the standard compass and at that of the Fox. Observe particularly whether the points of no deviation are the same. It simplifies matters greatly that they should be so, and that at both positions the points of no deviation should be nearly the north and south points. This they will most probably be in a vessel which will not have much iron near either position; but it will be advantageous, when first choosing the positions, to try roughly,—by means of a couple of compasses, one in the proposed position of the standard compass, and the other in that of the Fox,—whether they point alike when the ship's head is either north or south. By interchanging the compasses in these positions, you will prevent any deception which might arise from compass errors. "The observations which have been described will give you the value of the constants $a$ and $b$, for the corrections of all the declinations observed on board throughout the voyage, and you will probably find that they will give you work enough for one day. "3. I shall suppose therefore that you take a second day for the determination of the four constants at the position of the Fox. For this you will require the inclination and intensity with the ship's head on the same sixteen points as before, employing a deflector for the intensity on this occasion, in preference to weights, as more convenient. You will find of course that the points of no deviation with the compass become the points of extreme deviation of the inclination and intensity; for convenience I shall suppose them north and south points. Having completed the observations with the Fox, remove it and observe the horizontal intensity with the head successively north, east, south and west, and north again*, placing the apparatus for the horizontal intensity on the gimball stand of the Fox. This will give you $a$ and $b$ for that position more satisfactorily than the observations of the Fox; from these latter, with the shore observations, you will have $c$ and $d$. "The formulæ applicable to all the proceedings which have been described, will be found in Mr. Smith's Memorandum in No. V. of the Contributions to Terrestrial Magnetism. But besides the induced magnetism to which these formulæ refer, the * "These are compass points, the compass being supposed in strictness to be placed on the spot of the gimball table; if a compass placed at this spot has been found to agree with the standard compass, the latter gives directly the required azimuth of the ship's head." iron of a ship is found sometimes to exercise upon its compasses a magnetic influence of a distinct character, to which it may become in some instances desirable to give a separate consideration. This influence may be either from permanent magnetism strictly so called, or from a polarity which is temporarily retained, and undergoes alterations consequent upon changes in the inducing action in which it originated, but following after them at a greater or less interval of time. This additional magnetic force may be represented by additional symbols, P, Q and R, i.e. the force resolved along the principal section of the ship, transversely to it, and in the vertical direction. "The alterations which the introduction of this force makes in Mr. Smith's formula are stated in a second memorandum now printing in No. VI. of the Contributions, a copy of which will be in your hands before you sail. "This memorandum furnishes equations by which all the constants may be determined by observations in different magnetic latitudes,—of the horizontal force on the four principal points,—and of the dip on the two principal, together with the dip and horizontal force observed on shore or on the ice. These are part of the observations already directed. "4. The observations described in No. 3 must be repeated on the return to the Cape at the conclusion of the voyage, before any change has been made in the iron of the ship. If polarity due to the inducing action of a higher magnetic latitude has been retained, the observations on the return will be found to differ from those made before you sailed. If the disturbing influence of the ship's iron be solely the effect either of instantly induced magnetism, or of permanent magnetism strictly so called, the observations will agree with those made before the departure of the vessel. "5. If in the course of the voyage you should anchor in any port in a high latitude, at Enderby's Land for example, or at the Adelie Land of d'Urville, it will be extremely desirable to repeat the same observations. Whenever a choice exists between the shore and fixed ice, as a place for observation out of the influence of the ship's iron, always prefer the fixed ice. "6. The approximate value of \(a\), the most important of the constants, may be obtained on board at any time during the voyage when the weather is sufficiently favourable, by azimuths at the north or south points and at the east or west points for the position of the standard compass, and by the horizontal intensity observed on the north and south points for the position of the Fox. If Hansteen's needles are used for the latter purpose, and \(n, s\), be the number of vibrations at north and south in a certain time, commencing at the same arc, and performed in a nearly uniform temperature, then \(\frac{n}{s} = \tan \lambda\), and \(\cos 2 \lambda = a \tan \theta\); also if \(\Delta =\) the deviation when \(\zeta = 90^\circ\), \[ \Delta = 90^\circ - 2\lambda. \] "7. The horizontal intensity at the north and south points should be observed on board frequently; those on the north, south, east and west points, occasionally; and the dip and horizontal intensity on shore or on the ice, with corresponding observations on board, as often as possible. "8. Index Correction.—The most convenient mode of employing Mr. Fox's apparatus at sea being to use it with the face of the circle in one direction only (i.e. east or west, I shall here assume it east), the index correction with the face east must be sought, by a comparison of the Inclinations observed in that position of the instrument on shore and on fixed ice, with the true Inclinations determined with needles whose poles may be reversed and a complete observation made with them. As the index correction is liable to vary as a function of the Inclination, it should be determined in different Inclinations, and for this purpose it will be desirable to obtain at least one determination in a high latitude. "When observing on shore or on the ice for the index correction with the face east, do not omit to observe with the face west also, as the mean index correction is useful in showing the kind of separation which exists between the centre of gravity and the point of suspension in the needle for which it is determined. Mr. Fox's apparatus is furnished with three needles; one to be used when the poles are required to be reversed; the magnetism of the other two should be preserved from change if possible; it has been found a convenient practice to employ one of the latter always as the mounted needle, and the other as a deflector. "9. Comparison of the Weights and Deflectors.—Experience has shown that the intensity may be more conveniently and satisfactorily determined on board ship by the use of deflectors than by constant weights. "It is necessary however that the 'equivalent weights' of the deflectors employed should be carefully ascertained. Besides the table which you will form for this purpose in the manner practised by Mr. Fox, it will be necessary to have comparisons between the angles of deflection produced by the deflectors and the constant weights at the Cape before and after the voyage, and on any opportunity which you may have in a high latitude either on shore or on the ice. You may also get occasional comparisons on board in very favourable weather. "In the choice of constant weights to be employed during the voyage, use none that give a less angle of deflection than $15^\circ$. In the observations at the Cape, as your base station, make a double series (i.e. the same observations repeated on two separate days) both before and after the voyage. "10. Azimuths.—You will find it a convenient practice to deduce your azimuths from the hour angle, instead of from the altitude, which is the more usual custom. First take the altitudes which will give you the hour angle corresponding to the time by chronometer (at least until you materially change your geographical position); and as soon as you have completed this observation, take the sun's azimuth, noting the time of observation by chronometer; the hour angle will then give you the true azimuth. Blank forms are sent suited to this mode of observation. MDCCXLVI. "11. General Remarks.—You cannot do better than follow the admirable example of the Antarctic Expedition, in observing the three magnetic elements on board every day on which the weather will permit you to use the instruments. "12. Frequent reference has been made in these instructions to the importance of at least one opportunity of observing on shore or on the ice in a high latitude, for various objects connected with the reduction and correction of the whole body of magnetic observations made during the voyage. If Enderby's Land, or land connected with it, should not be accessible, it is by no means necessary that the ship should enter the ice in order to give you the opportunity of landing on a piece of ice of sufficient magnitude. A favourable day being chosen, she may approach the ice sufficiently near, and remain four or five hours, whilst her boat takes you to make the observations and to return. "If the ice be not 'fixed' you must be careful to detect an azimuthal motion, should there be any, by which the inclination circle might otherwise be removed from the plane of the magnetic meridian without your being aware of it. You will also take care that the magnetic instruments are sufficiently distant from the boat. "Edward Sabine." "Woolwich." The Pagoda sailed from the Cape of Good Hope on the 9th of January, proceeding, pursuant to instructions, towards the Antarctic Circle in the meridian of Greenwich. She crossed the 60th parallel in the longitude of 4° east, and being impeded by ice in her direct progress to the southward, coasted its margin to the south-east, and attained her greatest southing on the 10th of February in latitude —68° 10' and longitude 35°. She was then according to the chart in the vicinity of the western extremity of Enderby's Land, but from strong south-east gales and the position of the ice was unable to approach it sufficiently even to see the land: from thence she continued a general progress to the eastward, keeping in as high a parallel as the ice and weather permitted. On the 10th of March she had obtained the 96th degree of east longitude in about the 60th degree of latitude, when the season was considered to be so far advanced that it would not be prudent to persevere in the completion of the survey in the high latitudes; and a course was therefore taken for King George's Sound in Australia, where the ship arrived on the 1st of April. During the whole of this voyage observations of the three magnetic elements were made twice in each day, except in extreme circumstances of weather, by Lieut. Moore in the afternoon and Lieut. Clerk in the forenoon, each being furnished with a separate (Fox's) apparatus for the Inclination and Force; and on the arrival of the ship at King George's Sound, the two instruments were found to give an almost identical value for the intensity of the force, the results being by Lieut. Moore's Fox 1·680, and by Lieut. Clerk's 1·688. After remaining a sufficient time to examine the index and other corrections of the instruments, and to obtain the necessary data for eliminating the effects of the ship's iron on the magnetic results obtained during the voyage, the Pagoda quitted King George's Sound on the 27th of April and returned to the Cape of Good Hope, touching at Mauritius by the way for the purpose of repeating the observations on the influence of the ship's iron. She arrived at the Cape on the 20th of June, having continued the practice of observing the magnetic elements daily on the return passage, in the same manner as in the high latitudes. The voyage was performed without accident or loss of life, and the crew returned in perfect health, due doubtless in great degree to the supplies of warm clothing and preserved meats, which, by direction of the Admiralty, Lieut. Moore had taken with him from England. No failure occurred in any of the instruments notwithstanding the continual use in which they were kept by the zeal of the observers. If where so much was so well accomplished it is permissible to feel or to express regret on any account, it can be only that circumstances should have prevented the completion of the survey in the high latitudes as far as the 125th degree of longitude according to the original design, whereby the observations of the magnetic force would have been carried up to the principal axis of the isodynamic oval of 2°00'. On the conclusion of the voyage Lieut. Clerk received directions from the Master-General of the Ordnance to return to Woolwich, for the purpose of completing the reduction of his own observations and those of Lieut. Moore. The following pages contain Lieut. Clerk's report; in which he has also embodied a series of observations on the Inclination and Force with a Fox's apparatus, made in 1844 by Lieut. Alexander Smith, R.N., one of the Assistants at the Hobarton Magnetic Observatory, on his passage to Van Diemen Island; and a second series, also of the Inclination and Force, made in 1845 by Lieut. Dayman, R.N., of the same observatory, in a passage in the bark "Leander" from Hobarton to the Cape. Both these officers had previously been employed in the Antarctic Expedition under Sir James Clark Ross, and their observations now communicated are a consequence of the zeal which they imbued, and the practice in the use of instruments which they acquired, in that expedition. Their observations transmitted to the Admiralty were sent to Woolwich for reduction and publication. Lieut. Clerk has also embodied in his report the determinations of the three magnetic elements made by Sir James Ross in the Erebus in 1840 on her passage from the Cape of Good Hope to Kerguelen Island, and thence to Hobarton. On inspecting the map, it will be seen that the tracks of the Erebus and Prince Regent held about a middle line between the outward and homeward tracks of the Pagoda, and are therefore extremely useful in connecting results which would otherwise have been somewhat too far apart. Lieut. Clerk has taken the Cape of Good Hope as the base station of the observations of the magnetic force made in the Pagoda. The determinations of the absolute horizontal force made at the observatory at the Cape in February, March, April and May 1845 (page 362 in seq.), which are the last received from that station, give a mean result of $4^\circ 48'2"$, the mean inclination during the same month being $-53^\circ 25'5"$. Combining these with the determination at Woolwich in No. VII. of these Contributions*, we have the total force at the Cape in the arbitrary scale $0^\circ 993$. The ratios determined by Mr. Fox's statical apparatus (page 363 in seq.) by separate needles are $1^\circ 000$ and $1^\circ 006$: the value of the total force at the Cape as a base station for the observations of the Pagoda has therefore been taken as $1^\circ 000$. As Lieut. Smith did not touch at the Cape on his passage to Hobarton, and as the needle which Lieut. Dayman had employed on his homeward passage was broken at the Cape before observations had been made with it, and consequently before the series between Hobarton and the Cape could be connected with the latter station, it has been necessary to employ Hobarton as the base station of both these series. I have already stated in Nos. V. and VI. of these Contributions, the results of the observations which were made to determine the absolute horizontal force at Hobarton between 1840 and 1844; viz. by Sir James C. Ross in 1840 and 1841, with magnets of fifteen inches in length†; by Lieut. Kay in 1841 and 1842, with magnets of the same length‡; by Lieut. Kay in 1844 with magnets of twelve inches§, and with others of $9^\circ 18'$ and $7^\circ 50'$ inches||. I have now to add the results of twenty-four determinations made by Lieut. Kay between November 1844 and September 1845, with magnets of various lengths, as shown in the following table: | Magnets and their length. | Date. | No. of distances. | Horizontal force. | |---------------------------|-------------|-------------------|------------------| | Suspended. | Deflecting. | | | | in. | in. | | | | --- 7°50 | --- 9°18 | Nov. 7, 1844. | 3 | 4°5108 | | --- 7°50 | --- 9°18 | Sept. 9, 1845. | 3 | 4°4810 | | A 57 3°00 D xv. 3°67 | Dec. 7, 1844.| 3 | 4°5316 | | A 57 3°00 D xv. 3°67 | Dec. 9, 1844.| 5 | 4°5118 | | A 57 3°00 D xv. 3°67 | Dec. 11, 1844.| 5 | 4°4954 | | A 57 3°00 D xv. 3°67 | Jan. 12, 1845.| 5 | 4°5058 | | A 57 3°00 D xv. 3°67 | May 5, 1845.| 3 | 4°4997 | | A 57 3°00 D xv. 3°67 | Aug. 15, 1845.| 5 | 4°4758 | | A 57 3°00 D 9°3°67 | Aug. 19, 1845.| 5 | 4°5104 | | A 57 3°00 D 9°3°67 | May 6, 1845.| 3 | 4°5076 | | A 57 3°00 A 19 3°02 | Aug. 20, 1845.| 5 | 4°4905 | | A 52 3°00 D xi. 3°67 | Jan. 19, 1845.| 3 | 4°4940 | | R 1 3°00 D xvi. 3°67 | Aug. 28, 1845.| 4 | 4°4970 | | I 12 2°45 A 19 3°00 | Dec. 13, 1844.| 5 | 4°4954 | | I 12 2°45 A 19 3°00 | Dec. 13, 1844.| 5 | 4°4899 | | I 12 2°45 A 19 3°00 | Dec. 15, 1844.| 5 | 4°4865 | | I 12 2°45 A 19 3°00 | Jan. 14, 1845.| 5 | 4°4809 | | I 12 2°45 A 29 3°00 | Aug. 26, 1845.| 5 | 4°5016 | | I 12 2°45 A 23 3°00 | Aug. 22, 1845.| 5 | 4°4994 | | I 1 2°45 A 23 3°00 | Dec. 20, 1844.| 3 | 4°5046 | | I 1 2°45 A 23 3°00 | Dec. 23, 1844.| 3 | 4°5121 | | I 1 2°45 A 23 3°00 | Dec. 26, 1844.| 5 | 4°5020 | | I 1 2°45 A 23 3°00 | Jan. 15, 1845.| 5 | 4°5082 | | I 1 2°45 A 23 3°00 | May 9, 1845.| 3 | 4°4970 | Mean........................................... 4°4992 * Philosophical Transactions, 1846, p. 246. † Ibid. 1843, p. 168. ‡ Ibid. p. 168 (note). § Ibid. 1844, p. 111. || Ibid. p. 112. Collecting in one view the different mean results, we have Ross, in 1840–41, 15 in. magnets . . . . . . . . . . . . . . . . 4°573 Kay, in 1841, 15 in. magnets . . . . . . . . . . . . . . . . . . 4°553 Kay, in 1842, 15 in. magnets . . . . . . . . . . . . . . . . . . 4°513 Kay, in 1843, 12 in. magnets . . . . . . . . . . . . . . . . . . 4°520 Kay, in 1843, 9°18 and 7°50 in. magnets . . . . . . . . . . . . 4°501 Kay, in 1844–45, magnets of various lengths, 9°18 to 2°45 in. . . 4°499 These results exhibit (with one exception) a progressive decrease, but between those of 1840–41, and subsequent years, there is a very great difference. The inclination has decreased from −70° 40′7″, observed in 1840–41*, to −70° 37′6″, which is the mean of the results obtained twice in each week at the Hobarton Observatory in the first nine months of 1845. Assuming the total force at Hobarton as constant, the horizontal component should have been increased rather than diminished by the small secular change which appears to have taken place in the Inclination. The discrepancy between the earlier and later results of the absolute determinations cannot therefore be a consequence of secular change in the Inclination; nor is it probable that the total force should have undergone a decrease of such magnitude. Presuming the results of 1840–41, with the 15-inch magnets, to have been affected with error from some cause as yet unexplained, (possibly from an erroneous value having been taken for the moment of inertia of the magnet,) the subsequent results exhibit only such differences as cannot be regarded as excessive. They have all to undergo recalculation, as Lieut. Kay does not consider the elements of reduction as yet finally determined; and they will all, in common with all the other determinations of the absolute horizontal force given in these Contributions, have to receive a small correction for the difference of the magnetic moment of the deflecting bar, caused by the earth's inducing action in the different positions in which the bar is placed in the experiments of deflection and vibration. If, therefore, we assume provisionally the mean of the four last results, or 4°508, as the best approximation to which we have yet arrived for the horizontal component at Hobarton, and −70° 39′ as the corresponding Inclination, we have the total force in the arbitrary scale 1°797; and we may hence conclude, that influenced by the earlier determinations (those of 1840–41), the provisional value of the total force at Hobarton, employed in the Vth and VIth Numbers of the Contributions (1°82), was taken too high, and that all the values of the force dependent on Hobarton will require a correction to be applied, in amount about −0°02, before they are combined in the general map of the southern hemisphere. For Lieut. Smith’s and Lieut. Dayman’s observations, Lieut. Clerk has taken a base value of 1°80 at Hobarton. A subsequent number of these Contributions will contain the Magnetic Observations of the Erebus and Terror in the summer of 1843–1844, between the meridians * Philosophical Transactions, 1843, p. 165. of Cape Horn and of the Cape of Good Hope, which will complete the survey of the high latitudes of the southern hemisphere. I propose then to combine in one general view the several portions of the southern survey which have been successively communicated; and I shall reserve until that occasion, as more convenient than the present, such general remarks as suggest themselves in reference to the magnetic lines determined in the present Number. --- "Report on the Magnetic Observations made in Her Majesty's hired bark Pagoda, from January to June 1845, by Lieut. Henry Clerk of the Royal Artillery. "1. Calculation of Corrections for the Ship's Local Attraction. "To obtain the corrections for the observations of the Declination, the deviations of the compass were observed on each of the sixteen principal points at the Cape of Good Hope, King George's Sound, the Mauritius, and again at the Cape on the return of the Expedition. The following are the observations: | Ship's head | Cape of Good Hope | King George's Sound | Mauritius | |-------------|-------------------|--------------------|-----------| | | January | June | | | N. | 0° 12' + | 0° 26' + | 0° 15' + | | N.N.W. | 0° 57' + | Not observed | 0° 00' | | N.W. | 0° 08' - | 0° 50' + | 0° 20' + | | W.N.W. | 0° 00' | 0° 50' - | 1° 40' - | | W. | 0° 13' - | 0° 15' - | 1° 40' - | | W.S.W. | 0° 28' | 0° 30' - | 1° 50' - | | S.W. | 1° 28' | 1° 20' - | 1° 00' - | | S.S.W. | 1° 06' | 1° 25' - | 0° 15' - | | S. | *1° 48' + | 0° 18' - | 0° 50' + | | S.S.E. | 0° 42' + | Not observed | 0° 55' + | | S.E. | 1° 12' + | 1° 50' + | 2° 20' + | | E.S.E. | 1° 27' + | 1° 40' + | 3° 10' + | | E. | 0° 57' + | 1° 45' + | 2° 40' + | | E.N.E. | 0° 27' + | 1° 50' + | 3° 10' + | | N.E. | 0° 12' + | 1° 35' + | 3° 30' + | | N.N.E. | 0° 32' + | 1° 13' + | 2° 35' + | The + sign denotes a deviation of the north end towards the west. "The values of $\theta$ (the Inclination) being as follows, viz.— Cape of Good Hope . . . $\theta = -53° 44'$ King George's Sound . . . $\theta = -65° 04'$ Mauritius . . . . . . $\theta = -53° 56'$ "From these observations we can obtain the values of $a$ and $b$ by the formulæ in No. V. of the Contributions to Terrestrial Magnetism †, which give the following values, viz.— * This observation is evidently erroneous. † Philosophical Transactions, 1843, Part II. p. 148. Cape of Good Hope . . . \(a = '0148\) . . . \(b = '9848\) King George's Sound . . . \(a = '0199\) . . . \(b = '0040\) Mauritius . . . . . . \(a = '0158\) . . . \(b = '9907\) Mean . . . \(a = '0168\) . . . \(b = '9932\) "The values of \(a\) and \(b\) can also be obtained by observations of the horizontal intensity on the N., S., E. and W. points alone. "If the card of the azimuth compass be deflected by another magnet (the small deflectors belonging to the dipping-needle for instance), and if \(v_n\), \(v_s\), \(v_w\), and \(v_e\) be the angles of deflection observed on the N., S., W. and E. points respectively, then \[ a \tan \theta = \frac{\csc v_n - \csc v_s}{\csc v_n + \csc v_s}; \quad b = \frac{\csc v_w + \csc v_e}{2 \sqrt{\csc v_w \cdot \csc v_e}}. \] "The deflections were obtained in this manner at the Cape of Good Hope, and at King George's Sound on the N. and S. points, viz.—" | Cape of Good Hope | King George's Sound | |-------------------|--------------------| | At N. the deflection . . . = 16° 20 | At N. the deflection . . . = 15° 23 | | At S. . . . . . . . . = 15 35 | At S. . . . . . . . . = 14 06 | | Hence . . . . . . . . \(a = '0168\) | And . . . . . . . . \(a = '0198\) | Agreeing very closely with the values determined above. "After an inspection of the observations at the several stations, Mr. Archibald Smith has kindly furnished the following Memorandum. "The formulae for the correction of observations of magnetic declination, made on board ship, given in the Vth and VIth numbers of the Contributions, are deduced on the supposition that the soft iron of the ship is symmetrically distributed on each side of the fore and aft vertical section passing through the compass. The deviations observed in the Pagoda by Lieut. Clerk, seem to show that the soft iron was not so distributed in that vessel, and to require for their correction formulae in which no supposition is made as to the distribution of the iron of the vessel, except that there is no iron very near the compass. "Using the notation of the memorandums in Nos. V. and VI. of the Contributions, let \(\phi\) represent the total magnetic force of the earth at the place of observation, \(\theta\) the inclination, \(\zeta\) the azimuth of the ship's head, reckoning from (magnetic) north to west, and let \(\phi'\), \(\theta'\), \(\zeta'\) represent the values of the same quantities, shown by an instrument placed at a fixed position in the vessel, and affected by the attraction of the iron in the vessel. "The first three equations in the memorandum in Contribution No. VI. may be transformed into the following, viz.— \[ \begin{align*} \phi \cos \theta \cos \zeta &= \phi' \cos \theta' \{A' \cos \zeta' + B' \sin \zeta'\} + \phi' \sin \theta' C' + P'. \quad \ldots \quad (1.) \\ \phi \cos \theta \sin \zeta &= \phi' \cos \theta' \{D' \cos \zeta' + E' \sin \zeta'\} + \phi' \sin \theta' F' + Q'. \quad \ldots \quad (2.) \\ \phi \sin \theta &= \phi' \cos \theta' \{G' \cos \zeta' + H' \sin \zeta'\} + \phi' \sin \theta' K' + R'. \quad \ldots \quad (3.) \end{align*} \] "The coefficients $A' B' \ldots R'$ might, if required, be expressed in terms of the corresponding coefficients of Contribution No. VI. It is here however only important to observe that $A' B' C' D' E' F' G' H' K'$ depend only on the amount and distribution of the soft iron. $P' Q' R'$ depend partly on the amount and distribution of the permanently magnetic iron, and partly on the amount and distribution of the permanently magnetic iron, and become zero when there is no permanently magnetic iron. If the soft iron is symmetrically distributed on each side of the fore and aft vertical section passing through the compass, $B' D' F' H'$ are equal to zero. "The above equations are deduced, it must be remembered, on the hypothesis that the soft iron of the vessel receives its full charge of induced magnetism instantly on the vessel assuming a new position, and that the rest of the iron in the vessel is in a permanently magnetic state. On this hypothesis, and supposing that no iron is very near the compass, the equations are accurate, and the coefficients $A' B'$, &c. are constant, and independent of the latitudes. The hypothesis is however evidently not strictly true. The magnetic state of the hard, if not of the soft iron of the vessel, changes with a change of position and with time. In consequence of this, different values of the coefficients are derived from observations made at different places, and at the same place at different times. "Careful observations, made in a variety of circumstances and localities, and particularly, (for a reason which will appear in a subsequent part of this Memorandum,) observations made near the line of no dip, when the affected dip is zero, may hereafter throw light on the nature of the change which takes place in the magnetic state of a vessel, and furnish the means of determining the change which the coefficients undergo. In the present Memorandum they are supposed to be constant. "From equations (1.) and (2.) the following may be deduced: $$\sin (\zeta - \zeta') = \frac{\varphi' \cos \theta'}{\varphi \cos \theta} \left[ \frac{D' - B'}{2} - \frac{A' - E'}{2} \sin 2\zeta' + \frac{B' + D'}{2} \cos 2\zeta' \right]$$ $$- \frac{\varphi' \sin \theta' C' + P'}{\varphi \cos \theta} \sin \zeta' + \frac{\varphi' \sin \theta' F' + Q'}{\varphi \cos \theta} \cos \zeta'$$ (4.) "This equation is rigorously accurate, on the assumptions which have been made. If $\varphi' \cos \theta'$ and $\varphi' \sin \theta'$ were known in terms of $\varphi$, $\theta$ and $\zeta'$, and the coefficients determined by observation, this equation would furnish accurate corrections for observations of Declination. The expression is very much simplified if we may assume $\theta' = \theta$, and $\varphi' = \varphi$. This assumption may I believe in general be safely made, except in high magnetic latitudes. Making this assumption, we have the following approximate formula, $$\sin (\zeta - \zeta') = \frac{D' - B'}{2} - \left[ C' \tan \theta + \frac{P'}{\varphi \cos \theta} \right] \sin \zeta' + \left[ F' \tan \theta + \frac{Q'}{\varphi \cos \theta} \right] \cos \zeta'$$ $$- \frac{A' - E'}{2} \sin 2\zeta' + \frac{B' + D'}{2} \cos 2\zeta'$$ (5.) "This equation may conveniently be put under the form $$\sin \delta = A + B \sin \zeta' + C \cos \zeta' + D \sin 2\zeta' + E \cos 2\zeta'$$ (6.) δ = ζ - ζ' is the deviation of the compass; B corresponds to the coefficient \(a \tan \theta\) of the former memorandum; D to the coefficient \(1 - b\). A, B, C, D, E are coefficients, which are to be determined by observations of deviation made with the ship's head on different azimuths. A, D and E, it will be seen, are independent of the dip, and, to the extent to which the hypothesis above mentioned is correct, will have the same values in different latitudes. B and C depend on the dip, and also on the proportion of the soft to the permanently magnetic iron. This ratio cannot be determined from observations made in one place. If \(P'\), \(Q'\), \(C'\), \(F'\) remain constant, they can severally be determined from values of B and C deduced in two different latitudes, and the values of B and C in any other latitude may be deduced from the equations \[ B = -\left\{ C' \tan \theta + \frac{P'}{\phi \cos \theta} \right\} \quad (7.) \] \[ C = F' \tan \theta + \frac{Q'}{\phi \cos \theta} \quad (8.) \] the accurate values of B and C being \[ B = -\frac{\phi' \sin \theta' C' + P'}{\phi \cos \theta'}, \quad C = \frac{\phi' \sin \theta' F' + Q'}{\phi \cos \theta}. \] If the affected dip is zero, we have \[ R = -\frac{P'}{\phi}, \quad C = \frac{Q'}{\phi}. \] So that from observations on the line of no dip, or more accurately when the affected dip is zero, the effect of the permanent magnetism may be obtained. "If we distinguish the points of the compass, reckoning from north to west, by the numbers from 1 to 32, north being 0 or 32, and north by west being 1; and if we designate by δ₀, δ₁, &c. the westerly deviation when the ship's head is north, or north by west, &c., so that δ₈ represents the deviation at W., δ₁₆ at S., δ₂₄ at E., it is evident from the equations that we have at once the following simple expressions for the values of the coefficients: \[ A = \frac{1}{4} \left\{ \sin \delta_0 + \sin \delta_8 + \sin \delta_{16} + \sin \delta_{24} \right\}. \quad (9.) \] \[ B = \frac{1}{2} \left\{ \sin \delta_8 - \sin \delta_{24} \right\}. \quad (10.) \] \[ C = \frac{1}{2} \left\{ \sin \delta_0 - \sin \delta_{16} \right\}. \quad (11.) \] \[ D = \frac{1}{4} \left\{ \sin \delta_4 - \sin \delta_{12} + \sin \delta_{20} - \sin \delta_{28} \right\}. \quad (12.) \] \[ E = \frac{1}{4} \left\{ \sin \delta_0 - \sin \delta_8 + \sin \delta_{16} - \sin \delta_{24} \right\}. \quad (13.) \] "More accurate values of the coefficients may be obtained by combining observations of deviation, made with the ship's head on the several points, in the following manner: "1. Suppose the deviation to have been observed on all the thirty-two points. Let $\zeta_1', \zeta_2', \ldots, \zeta_{32}'$ be the observed azimuths, which of course are $11^\circ 15'$, $22^\circ 30'$, &c. Then we have \[ \begin{align*} \sin \delta_0 &= A + C + E \\ \sin \delta_1 &= A + B \sin \zeta_1' + C \cos \zeta_1' + D \sin 2\zeta_1' + E \cos 2\zeta_1' \\ \sin \delta_2 &= A + B \sin \zeta_2' + C \cos \zeta_2' + D \sin 2\zeta_2' + E \cos 2\zeta_2' \\ &\text{&c.} & &\text{&c.} \\ \sin \delta_{31} &= A + B \sin \zeta_{31}' + C \cos \zeta_{31}' + D \sin 2\zeta_{31}' + E \cos 2\zeta_{31}' \end{align*} \] Combining these equations by the method of least squares, we obtain by virtue of a well-known property of circular functions, \[ \begin{align*} A &= \frac{1}{32} \sum \sin \delta \\ B &= \frac{1}{16} \sum \sin \delta \sin \zeta' \\ C &= \frac{1}{16} \sum \sin \delta \cos \zeta' \\ D &= \frac{1}{16} \sum \sin \delta \sin 2\zeta' \\ E &= \frac{1}{16} \sum \sin \delta \cos 2\zeta' \end{align*} \] where \[ \begin{align*} \sum \sin \delta &= \sin \delta_0 + \sin \delta_1 + \ldots + \sin \delta_{31}, \\ \sum \sin \delta \sin \zeta' &= \sin \delta_0 \sin \zeta_0' + \sin \delta_1 \sin \zeta_1' + \text{&c.} + \sin \delta_{31} \sin \zeta_{31}', \\ \sum \sin \delta \cos \zeta' &= \sin \delta_0 \cos \zeta_0' + \sin \delta_1 \cos \zeta_1' + \text{&c.} + \sin \delta_{31} \cos \zeta_{31}', \\ \sum \sin \delta \sin 2\zeta' &= \sin \delta_0 \sin 2\zeta_0' + \sin \delta_1 \sin 2\zeta_1' + \text{&c.} + \sin \delta_{31} \sin 2\zeta_{31}', \\ \sum \sin \delta \cos 2\zeta' &= \sin \delta_0 \cos 2\zeta_0' + \sin \delta_1 \cos 2\zeta_1' + \text{&c.} + \sin \delta_{31} \cos 2\zeta_{31}' \end{align*} \] If we represent $\sin \delta_0, \sin \delta_1, \text{&c.}$ by $s_0, s_1, \text{&c.}$, and remember that all the values of $\sin \zeta', \cos \zeta', \sin 2\zeta', \cos 2\zeta'$ which occur in these formulæ can be represented by the quantities $s_1, s_2, s_3, s_4, s_5, s_6, s_7$, we shall find \[ \begin{align*} A &= \frac{1}{32} \{s_0 + s_1 + s_2 + \ldots + s_{31}\}, \\ B &= 0.0122 (\log = 2.08611) \{s_1 - s_{31} + s_{15} - s_{17}\}, \\ &+ 0.0239 (\log = 2.37872) \{s_2 - s_{30} + s_{14} - s_{18}\}, \\ &+ 0.0347 (\log = 2.54062) \{s_3 - s_{29} + s_{13} - s_{19}\}, \\ &+ 0.0442 (\log = 2.64536) \{s_4 - s_{28} + s_{12} - s_{20}\}, \\ &+ 0.0520 (\log = 2.71572) \{s_5 - s_{27} + s_{11} - s_{21}\}, \\ &+ 0.0577 (\log = 2.76149) \{s_6 - s_{26} + s_{10} - s_{22}\}, \\ &+ 0.0613 (\log = 2.78745) \{s_7 - s_{25} + s_9 - s_{23}\}, \\ &+ \frac{1}{16} \{s_8 - s_{24}\}. \end{align*} \] C = \frac{1}{16} \{s_0 - s_{16}\}, + 0.0613 (\log = 2.78745) \{s_1 + s_{31} - s_{15} - s_{17}\}, + 0.0577 (\log = 2.76149) \{s_2 + s_{30} - s_{14} - s_{18}\}, + 0.0520 (\log = 2.71572) \{s_3 + s_{29} - s_{13} - s_{19}\}, + 0.0442 (\log = 2.64536) \{s_4 + s_{28} - s_{12} - s_{20}\}, + 0.0347 (\log = 2.54062) \{s_5 + s_{27} - s_{11} - s_{21}\}, + 0.0239 (\log = 2.37872) \{s_6 + s_{26} - s_{10} - s_{22}\}, + 0.0122 (\log = 2.08611) \{s_7 + s_{25} - s_9 - s_{23}\}. . . . . . . . . . . . (18.) D = 0.0577 (\log = 2.76149) \{s_1 - s_{31} - s_{15} + s_{17} + s_7 - s_{25} - s_9 + s_{23}\}, + 0.0442 (\log = 2.64536) \{s_2 - s_{30} - s_{14} + s_{18} + s_6 - s_{26} - s_{10} + s_{22}\}, + 0.0229 (\log = 2.37872) \{s_3 - s_{29} - s_{13} + s_{19} + s_5 - s_{27} - s_{11} + s_{21}\}, + \frac{1}{16} \{s_4 - s_{28} - s_{12} + s_{20}\}. . . . . . . . . . . . . . . . . . (19.) E = \frac{1}{16} \{s_0 + s_{16} - s_8 - s_{24}\}, + 0.0239 (\log = 2.37872) \{s_1 + s_{31} + s_{15} + s_{17} - s_7 - s_{25} - s_9 - s_{23}\}, + 0.0442 (\log = 2.64536) \{s_2 + s_{30} + s_{14} + s_{18} - s_6 - s_{26} - s_{10} - s_{22}\}, + 0.0577 (\log = 2.76149) \{s_3 + s_{29} + s_{13} + s_{19} - s_5 - s_{27} - s_{11} - s_{21}\}. . . . . . . . . . . . (20.) 2. Using the deviations observed on the sixteen principal points only, we have A = \frac{1}{16} \{s_0 + s_2 + s_4 . . . . . . + s_{30}\}. . . . . . . . . . . . . . . . . . (21.) B = 0.0478 (\log = 2.67975) \{s_2 - s_{30} + s_{14} - s_{18}\}, + 0.0884 (\log = 2.94639) \{s_4 - s_{28} + s_{12} - s_{20}\}, + 0.1155 (\log = 1.06252) \{s_6 - s_{26} + s_{10} - s_{22}\}, + \frac{1}{8} \{s_8 - s_{24}\}. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (22.) C = \frac{1}{8} \{s_0 - s_{16}\}, + 0.1155 (\log = 1.06252) \{s_2 + s_{30} - s_{14} - s_{18}\}, + 0.0884 (\log = 2.94639) \{s_4 + s_{28} - s_{12} - s_{20}\}, + 0.0478 (\log = 2.67975) \{s_6 + s_{26} - s_{10} - s_{22}\}. . . . . . . . . . . . . . . . . . (23.) D = 0.0884 (\log = 2.94639) \{s_2 - s_{30} - s_{14} + s_{18} + s_6 - s_{26} - s_{10} + s_{22}\}, + \frac{1}{8} \{s_4 - s_{28} - s_{12} + s_{20}\}. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (24.) E = \frac{1}{8} \{s_0 + s_{16} - s_8 - s_{24}\}, + 0.0884 (\log = 2.94639) \{s_2 + s_{30} + s_{14} + s_{18} - s_6 - s_{10} - s_{22} - s_{26}\}. . . . . . . . . . . . . . . . . . (25.) Using the deviations observed on the eight principal points only, we have \[ A = \frac{1}{8} \left( s_0 + s_4 + s_8 + \cdots + s_{28} \right) \] \[ B = 1768 (\log 1.24742) \left( s_4 - s_{28} + s_{12} - s_{20} \right) + \frac{1}{4} \left( s_8 - s_{24} \right) \] \[ C = \frac{1}{4} \left( s_0 - s_{16} \right) + 1768 (\log 1.24742) \left( s_4 + s_{28} - s_{12} - s_{20} \right) \] \[ D = \frac{1}{4} \left( s_4 - s_{28} - s_{12} + s_{20} \right) \] \[ E = \frac{1}{4} \left( s_0 + s_{16} - s_8 - s_{24} \right) \] Having found A, B, C, D, E by any of the above methods, a table of the deviations on all the points may then be computed. The computation will be facilitated by using the following Table: Let \( B_1, B_2, \ldots, B_7, C_1, C_2, \ldots, C_7 \) represent the values of B and C multiplied by \( \sin 11^\circ 15' \), \( \sin 22^\circ 30' \), and let \( D_2, D_4, D_6, E_2, E_4, E_6 \) represent the values of D and E multiplied by \( \sin 22^\circ 30' \), \( \sin 45^\circ \), and \( \sin 67^\circ 30' \), we have then \[ \begin{align*} \sin \delta_0 &= A + C + E \\ \sin \delta_{16} &= A - C + E \\ \sin \delta_1 &= A + B_1 + C_7 + D_2 + E_6 \\ \sin \delta_{31} &= A - B_1 + C_7 - D_2 + E_6 \\ \sin \delta_{15} &= A + B_1 - C_7 - D_2 + E_6 \\ \sin \delta_{17} &= A - B_1 - C_7 + D_2 + E_6 \\ \sin \delta_2 &= A + B_2 + C_6 + D_4 + E_4 \\ \sin \delta_{30} &= A - B_2 + C_6 - D_4 + E_4 \\ \sin \delta_{14} &= A + B_2 - C_6 - D_4 + E_4 \\ \sin \delta_{18} &= A - B_2 - C_6 + D_4 + E_4 \\ \sin \delta_3 &= A + B_3 + C_5 + D_6 + E_2 \\ \sin \delta_{29} &= A - B_3 + C_5 - D_6 + E_2 \\ \sin \delta_{13} &= A + B_3 - C_5 - D_6 + E_2 \\ \sin \delta_{19} &= A - B_3 - C_5 + D_6 + E_2 \\ \sin \delta_4 &= A + B_4 + C_4 + D \\ \sin \delta_{28} &= A - B_4 + C_4 - D \\ \sin \delta_{12} &= A + B_4 - C_4 - D \\ \sin \delta_{20} &= A - B_4 - C_4 + D \end{align*} \] \[ \begin{align*} \sin \delta_5 &= A + B_5 + C_3 + D_6 - E_2 \\ \sin \delta_{27} &= A - B_5 + C_3 - D_6 - E_2 \\ \sin \delta_{11} &= A + B_5 - C_3 - D_6 - E_2 \\ \sin \delta_{21} &= A - B_5 - C_3 + D_6 - E_2 \\ \sin \delta_6 &= A + B_6 + C_2 + D_4 - E_4 \\ \sin \delta_{26} &= A - B_6 + C_2 - D_4 - E_4 \\ \sin \delta_{10} &= A + B_6 - C_2 - D_4 - E_4 \\ \sin \delta_{22} &= A - B_6 - C_2 + D_4 - E_4 \\ \sin \delta_7 &= A + B_7 + C_1 + D_2 - E_6 \\ \sin \delta_{25} &= A - B_7 + C_1 - D_2 - E_6 \\ \sin \delta_9 &= A + B_7 - C_1 - D_2 - E_6 \\ \sin \delta_{23} &= A - B_7 - C_1 + D_2 - E_6 \\ \sin \delta_8 &= A + B - E \\ \sin \delta_{24} &= A - B - E. \end{align*} \] "If the deviations are under \(7^\circ\) or \(8^\circ\), the angles of deviation may be used in the formulae instead of the sines of the angles without producing a sensible error in the result. "It may be observed that \(\phi' \cos \theta'\) and \(\phi' \sin \theta'\) would be themselves properly expressed in a series containing sines and cosines of \(2\zeta'\) and \(2\zeta'\), and this would introduce into the expression for \(\sin \delta\) terms of the form \[F \sin 3\zeta' + G \cos 3\zeta' + H \sin 4\zeta' + K \cos 4\zeta'.\] "The omission of these terms from the formula we have used does not affect the values we have found for \(A, B, C, D, E\); and the values of the additional coefficients may be determined from the following expressions, in which we make use of the observations on the sixteen principal points only:— \[F = 0.1155 (\log = \frac{1}{0.0625}) S_2 + S_{30} + S_{14} - S_{18},\] \[+ 0.0884 (\log = \frac{2}{0.9463}) S_4 - S_{28} + S_{12} - S_{20},\] \[- 0.0478 (\log = \frac{2}{0.6797}) S_6 - S_{26} + S_{10} - S_{22},\] \[- \frac{1}{8} (S_8 - S_{24}).\] (31.) \[G = \frac{1}{8}(S_0 - S_{16})\] \[+ 0.0478 (\log = \frac{2}{0.6797}) S_2 + S_{30} - S_{14} - S_{18},\] \[- 0.0884 (\log = \frac{2}{0.9463}) S_4 + S_{28} - S_{12} - S_{20},\] \[- 0.1155 (\log = \frac{1}{0.0625}) S_6 + S_{26} - S_{10} - S_{22}.\] (32.) \[H = \frac{1}{16}(S_2 - S_{30} - S_{14} + S_{18} - S_6 + S_{26} - S_{10} - S_{22}).\] (33.) \[K = \frac{1}{16}(S_0 + S_{16} + S_8 + S_{24} - S_4 - S_{28} - S_{12} - S_{20}).\] (34.) "If the deviations are so small that the angles may be used instead of their sines, then the differences between the observed deviations and the deviations calculated with the first five terms may be used instead of $s_2$, $s_4$, &c. in finding F and G or H and K. There is however no advantage gained thereby, as the quantities within the brackets in F and G have already been found in calculating B and C. "As an example of the use of these formulæ, we may take the deviations observed on board Her Majesty's ship Erebus at Gillingham, in Sept. 1839*. "From the deviations observed on the sixteen principal points, I find $$\delta = 17' + 235' \sin \zeta' - 13' \cos \zeta' + 21' \sin 2\zeta' - 1'23 \cos 2\zeta'.$$ "From the deviations on the eight principal points, I find $$\delta = 16' + 233'5 \sin \zeta' - 14' \cos \zeta' + 21 \sin 2\zeta' - 0'75 \cos 2\zeta'.$$ "Applying the correction derived from the first formula, the residuary differences on the sixteen principal points, beginning with north, are respectively— $-3', 0, +6', +14', -6', -18', +12', +7', +1', -11', -12', -9', +5', +7', +6', 0.$ "These differences evidently nearly follow the law of $\sin 3\zeta'$; they give $$F = 5'5; \quad G = -7'.$$ "After applying the correction $5'5 \sin 3\zeta' - 7' \cos 3\zeta'$, the residuary difference is $+4' -2', -3', +9', 0', -9', +13', -1', -6', -9', -3', -4', -1', -2', +5', +8'.$ "The differences, it will be seen, are smaller, and do not distinctly follow any regular law. If we calculate H and K we shall find $$H = 2'; \quad K = 1'.$$ But these corrections are so much within the errors of observation, that there could be no advantage in using them. "The expression for $\sin \delta$ may be put under the following form, viz.— $$\sin \delta = A + \sqrt{B^2 + C^2} \sin (\zeta + \alpha) + D \sin 2\zeta' + E \cos 2\zeta', \ldots \quad (35.)$$ in which $\alpha$ is the angle whose tangent is $\frac{C}{B}$, and is nearly the easterly azimuth of the line of no deviation. "It seems probable that in ordinary cases A, $\alpha$, D and E will not change materially with a change of latitude, while $\sqrt{B^2 + C^2}$ will vary nearly as the tangent of the dip. The last-mentioned term is also the most important, from its magnitude and its dependence on the changes which the permanent magnetism undergoes. It may therefore be useful to have the means of obtaining this quantity separately. This may be done from observations of the horizontal force, made in the position of the standard compass, with the ship's head on any two opposite (affected) courses, from the formula $$\sqrt{B^2 + C^2} = \frac{\sqrt{H_1^2 + H_2^2 + 2H_1H_2 \cos (\text{diff. of true azimuth})}}{H_1 + H_2}, \ldots \quad (36.)$$ * Contributions, No. V., p. 150. in which $H_1$ $H_2$ represent the observed horizontal force in the two positions of the ship's head. "If the difference of the true azimuths of the ship's head is 180°, the expression becomes $$\sqrt{B^2+C^2} = \pm \frac{H_1-H_2}{H_1+H_2}, \ldots \ldots \ldots \ldots (37.)$$ which is the same expression as that for the value of $\alpha \tan \theta$ in the Memorandum in No. V. of these Contributions. "The value of the horizontal force may be determined by vibrating a horizontal needle, or by deflecting the compass needle in the manner described by Lieut. Clerk in page 347. The difference of azimuths may be determined by the bearings of a distant object, or astronomically. "This method seems to be adapted to the case of a ship lying at moorings in a tideway. The observations may be made before and after the change of tide, and the rudder adjusted so that the difference of the compass bearings of the ship's head may be exactly 180°. "This formula is more accurate the more nearly the dip approaches to 90°; and the method seems therefore particularly applicable in high magnetic latitudes. "If the true magnetic azimuth of the ship's head on the two positions is determined, the values of B and C may be obtained by the formula $$B = -\frac{H_2 \cos \zeta_1 + H_1 \cos \zeta_2}{H_1 + H_2},$$ $$C = \frac{H_2 \sin \zeta_1 + H_1 \sin \zeta_2}{H_1 + H_2}.$$ "A. S." "Lincoln's Inn, March 3, 1846." "The constants for correcting the declination observations were (in consequence of this Memorandum) calculated by the equations 21, 22, 23, 24 and 25, taking the mean of the two series at the Cape of Good Hope. "The following are the deduced values of the constants: | Station | $\delta$ | $\phi$ | A | B | C | D | E | |--------------------------|----------|----------|-------|-------|-------|-------|-------| | Cape of Good Hope | -53° 44' | 1°013 | +0.00600 | -0.01412 | +0.00742 | +0.00911 | -0.00333 | | Mauritius | -53° 56' | 1°158 | +0.00479 | -0.01550 | +0.00514 | +0.00448 | +0.00335 | | King George's Sound | -65° 04' | 1°703 | +0.01453 | -0.03295 | +0.00658 | -0.00156 | +0.00082 | | Means | -57° 35' | 1°291 | +0.00844 | -0.02086 | +0.00638 | +0.00401 | +0.00028 | "From the three values of B, and C, values of $C'$ and $P'$, $F'$ and $Q'$ were obtained by the equations $$B = -(C' \tan \theta + \frac{P}{\phi \cos \theta}); \quad \text{and} \quad C = F' \tan \theta + \frac{Q}{\phi \cos \theta};$$ for we have \[ \begin{align*} \text{Cape} & : -0.01412 = C' \times 1.363 + P' \times 1.669; \\ \text{Mauritius} & : -0.01550 = C' \times 1.373 + P' \times 1.467; \\ \text{King George's Sound} & : -0.03295 = C' \times 2.151 + P' \times 1.393; \end{align*} \] also \(+0.00742 = -1.363F' - 1.669Q'\) \(+0.00514 = -1.373F' - 1.467Q'\) \(+0.00658 = -2.151F' - 1.393Q'\). Hence by elimination we obtain \[ \begin{align*} C' &= -0.0209; \\ F' &= -0.0006; \\ P' &= +0.0088; \\ Q' &= -0.0034. \end{align*} \] "From the values of \(C'\), \(P'\), \(F'\) and \(Q'\), a table of the values of \(B\) and \(C\) in different dips and intensities was formed, and from them with the mean values of \(A\), \(D\) and \(E\), a table for correcting the observations of Declination was calculated by equ. 35. The corrections thus obtained appear to give very closely the true corrections, at all events much within the limits of observation errors. The following is a comparison between the observed and calculated deviations at King George's Sound, \(\theta\) being \(-65^\circ 04'\), and \(\phi = 1^\circ 70\). | Ship's head. | \(b\) by calculation. | \(b\) by observation. | Difference. | Ship's head. | \(b\) by calculation. | \(b\) by observation. | Difference. | |--------------|----------------------|----------------------|-------------|--------------|----------------------|----------------------|-------------| | N. | +0 52 | +0 15 | -0 37 | S. | +0 03 | +0 50 | +0 47 | | N.N.W. | +0 17 | 0 00 | -0 17 | S.S.E. | +0 47 | +0 55 | +0 08 | | N.W. | -0 21 | +0 20 | +0 41 | S.E. | +1 25 | +2 20 | +0 55 | | W.N.W. | -0 58 | -1 40 | -0 42 | E.S.E. | +2 02 | +3 10 | +1 08 | | W. | -1 25 | -1 40 | -0 15 | E. | +2 25 | +2 40 | +0 15 | | W.S.W. | -1 16 | -1 50 | -0 34 | E.N.E. | +2 17 | +3 10 | +0 53 | | S.W. | -0 54 | -1 00 | -0 06 | N.E. | +1 52 | +3 30 | +1 38 | | S.S.W. | -0 24 | -0 24 | +0 09 | N.N.E. | +1 22 | +2 35 | +1 13 | + Sign denotes a deviation towards the west. "It appears from this comparison, that the calculated corrections are smaller in amount than the observed. As the ship had just returned from a high magnetic latitude, it is probable that the observed corrections belonged to a greater dip than the one at the station, and therefore that the corrections would be more nearly represented by taking them out from the Table for a larger Inclination and Intensity. The great differences on the E.S.E., N.E. and N.N.E. points are caused most probably by errors of observation. "The correctness of equation (6.) will be more easily perceived by the accordance of observations made at sea, in a high dip, making due allowance for the difficulty of observing in bad weather. "2. Calculation of Corrections for the Inclination Observations. "To obtain these corrections four constants are necessary, viz. \(a\), \(b\), \(c\), \(d\); \(a\) and \(b\) are obtained from the deviations of a compass (placed on the same spot as the dipping- needle) on the sixteen principal points. The following are the observations at King George's Sound, the Mauritius, and the Cape of Good Hope. | Ship's head | King George's Sound | Mauritius | Cape of Good Hope | |-------------|---------------------|-----------|-------------------| | N. | -0° 45' | -0° 05' | -0° 25' | | N.N.W. | -1° 15' | -1° 25' | Not observed | | N.W. | -2° 05' | -1° 45' | -0° 05' | | W.N.W. | -3° 20' | -2° 25' | -0° 35' | | W. | -3° 35' | -3° 05' | -0° 50' | | W.S.W. | -3° 45' | -3° 05' | -1° 15' | | S.W. | -1° 55' | -1° 35' | -1° 45' | | S.S.W. | *3° 00' | -1° 05' | -0° 35' | | Ship's head | King George's Sound | Mauritius | Cape of Good Hope | |-------------|---------------------|-----------|-------------------| | S. | Not observed | +1° 25' | -0° 50' | | S.S.E. | +2° 40' | +1° 15' | Not observed | | S.E. | +3° 25' | +1° 10' | +1° 55' | | E.S.E. | +3° 25' | +1° 50' | +2° 35' | | E. | +3° 25' | +2° 15' | +2° 40' | | E.N.E. | +2° 35' | +1° 05' | +1° 10' | | N.E. | +2° 45' | +0° 35' | +0° 45' | | N.N.E. | +2° 20' | +0° 25' | +0° 05' | "Allowing for the errors of observation, it appears from these observations that the iron is symmetrically distributed in reference to the compass placed on the same spot where the observations of inclination and intensity were made, and therefore that we may use the equations in Contributions V. and VI. "From these equations the values of \(a\) and \(b\) are found, At King George's Sound . . . . \(a = '0296\); \(b = '9867\); Mauritius . . . . . . . . \(a = '0272\); \(b = '9910\); Cape of Good Hope . . . . . \(a = '0192\); \(b = '9766\). "The values of \(a\) and \(b\) can be found independently of the compass, from the observations of dip and intensity themselves, \(A'\) being supposed \(= 1\), by means of the formulae \[a \sin \theta = \frac{\phi'}{\phi} \cos \theta' \cos \zeta' - \cos \theta \cdot \cos \zeta,\] and \[b \cos \theta = \frac{\phi'}{\phi} \cos \theta' \sin \zeta' \cos \zeta.\] "Values of \(\phi'\) and \(\theta'\) were obtained from observations on the sixteen principal points of the compass made at King George's Sound, Mauritius, and the Cape of Good Hope. They are as follows: Values of \(\theta'\). | Ship's head | Observed Inclination | Ship's head | Observed Inclination | |-------------|---------------------|-------------|---------------------| | N. | -66° 15' | s. | -64° 52' | | N.N.W. | -66° 33' | S.S.E. | -65° 00' | | N.W. | -66° 19' | S.E. | -65° 29' | | W.N.W. | -66° 07' | E.S.E. | -65° 52' | | W. | -65° 44' | E. | -66° 23' | | W.S.W. | -65° 42' | E.N.E. | -66° 07' | | S.W. | -65° 31' | N.E. | -66° 17' | | S.S.W. | -64° 48' | N.N.E. | -66° 31' | * This observation is not taken into account, being obviously erroneous. Values of $\phi'$. | Ship's head | Observed Intensity | Ship's head | Observed Intensity | |-------------|-------------------|-------------|-------------------| | | King George's Sound | Mauritius | Cape of Good Hope | King George's Sound | Mauritius | Cape of Good Hope | | N. | 1·737 | 1·150 | 1·024 | S. | 1·799 | 1·206 | 1·066 | | N.N.W. | 1·736 | 1·152 | 1·020 | S.E. | 1·797 | 1·204 | 1·055 | | N.W. | 1·734 | 1·151 | 1·025 | E.S.E. | 1·790 | 1·182 | 1·045 | | W.N.W. | 1·752 | 1·158 | 1·025 | E.S.E. | 1·773 | 1·189 | 1·032 | | W. | 1·758 | 1·166 | 1·028 | E. | 1·753 | 1·169 | 1·029 | | W.S.W. | 1·775 | 1·198 | 1·036 | E.N.E. | 1·757 | 1·166 | 1·024 | | S.W. | 1·790 | 1·191 | 1·049 | N.E. | 1·736 | 1·159 | 1·023 | | S.S.W. | 1·805 | 1·200 | 1·061 | N.N.E. | 1·735 | 1·155 | 1·023 | "The observed values of $\theta$ and $\phi$ are approximately— King George's Sound . . . $\theta = -65^\circ 11'$; $\phi = 1·733$ Mauritius . . . . . . $\theta = -54^\circ 14'$; $\phi = 1·158$ Cape of Good Hope . . . $\theta = -53^\circ 37'$; $\phi = 1·027$. "Substituting these values in equations (1.) and (2.), we have King George's Sound . . . $a = 0·0242$; $b = 0·9905$; Mauritius . . . . . . $a = 0·0234$; $b = 1·0105$; Cape of Good Hope . . . $a = 0·0186$; $b = 0·9916$. "Including these values with those obtained from the compass observations, we get the mean values for $a$ and $b$, $a = 0·0237$; $b = 0·9912$. "The constants $c$ and $d$ are calculated from the formula $c \cos \zeta + d \tan \theta = b \sin \zeta \cosec \zeta' \tan \theta'$ for the observations between N.N.W. and S.S.W., and N.N.E. and S.S.E.; and for the other points, viz. N. and S., by the formula $c \cos \zeta + d \tan \theta = (\cos \zeta + a \tan \theta) \sec \zeta' \tan \theta'$. "The values of $\zeta$ and $\theta'$ were given by the observations at the several stations. The values of $c$ and $d$ are as follows: King George's Sound . . . $c = 0·010$; $d = 1·054$; Mauritius . . . . . . $c = 0·014$; $d = 1·011$; Cape of Good Hope . . . $c = 0·003$; $d = 1·033$. The values of $c$ and $d$ were also obtained from the observations of dip and intensity, independently of $a$ and $b$, by the formula $c \cos \theta \cos \zeta - d \sin \theta = \frac{\phi'}{\phi} \sin \theta'$, A being supposed equal to unity; which gives the following values:— King George's Sound . . . \( c = 0.028; \quad d = 1.023; \) Mauritius . . . . . . \( c = 0.024; \quad d = 1.017; \) Cape of Good Hope . . . \( c = 0.021; \quad d = 1.020. \) "The mean of these six values makes \[ c = 0.017; \quad d = 1.026. \] "From these values of \( a, b, c \) and \( d \), a table of corrections was found by means of equations (12.) and (13.) (Contribution V.), employing calculated values of \( \zeta \). "In order to test the accuracy of the table, we may compare observed and calculated values of the dip at King George's Sound. It will be seen that on the northerly points the correction is rather too large, on the easterly and westerly too small, and nearly correct on the S., S.S.W. and S.S.E. points. The differences however are within the limits of observation errors. | Ship's head. | Observed Inclination. | Tabular correction. | Corrected Inclination. | |--------------|-----------------------|---------------------|-----------------------| | N. | -66° 15' | +1° 23' | -64° 52' | | N.N.W. and N.N.E. | -66° 32' | +1° 23' | -65° 09' | | N.W. and N.E. | -66° 18' | +1° 31' | -64° 47' | | W.N.W. and E.N.E. | -66° 07' | +1° 09' | -64° 58' | | W. and E. | -66° 03' | +0° 46' | -65° 17' | | W.S.W. and E.S.E. | -65° 47' | +0° 23' | -65° 24' | | S.W. and S.E. | -65° 30' | +0° 02' | -65° 28' | | S.S.W. and S.S.E. | -64° 54' | -0° 16' | -65° 10' | | S. | -64° 52' | -0° 18' | -65° 10' | The mean inclination observed on shore with the same needle being -65° 11'. "3. Calculation of Corrections for Intensity Observations. "The constant \( A \) is calculated from the above observations by means of the formula \[ \frac{\phi'}{N'\phi} \sin \theta' = c \cos \theta \cos \zeta + d \sin \theta. \] "The values of \( \theta', \phi' \) and \( \zeta \), are all given by the observations on the sixteen points of the compass; those of \( \phi \) and \( \theta \) by the observations on shore. The following are the resulting values for \( A' \), viz.— King George's Sound . . . \( A' = 0.998 \) Mauritius . . . . . . \( A' = 0.992 \) Cape of Good Hope . . . \( A' = 0.992 \) Mean . . . \( A' = 0.994 \) "This value being so near unity, \( A \) is assumed = 1.0, with which and the values of \( c \) and \( d \) already determined, a table of corrections was formed by means of the equation \[ \frac{\phi'}{\phi} = A'c \left( \frac{d}{c} \tan \theta + \cos \zeta \right) \cos \theta \csc \theta^*, \] \( \theta' \) and \( \zeta \) being obtained from the tables for correcting the dips and declinations. * Philosophical Transactions, 1843, Part II. p. 162. "II. Determination of Index Corrections. "1. Declination Observations. "The compass used was one of the Admiralty compasses (B. 20). It was supplied with two cards, one considerably heavier than the other to be used in bad weather; but as it was found that in all weathers the heavy card was the steadiest and gave the best results, it was accordingly generally used. The index corrections of both cards were determined at the Magnetic Observatory, Cape of Good Hope. The following are the means of several observations with each card; the mean monthly declination by the observatory declinometer being $+29^\circ 07'$. Card A (the light card) gave $+28^\circ 20'$; correction $+47'$. Card J (the heavy card) gave $+28^\circ 15'$; correction $+52'$. "These corrections have been applied to all the observations, according to the card employed. "2. Inclination Observations. "Two of Mr. Fox's instruments were kept in constant use, one observed in the forenoon and the other in the afternoon. In order to distinguish them, we may call the one observed in the morning No. 1, the other was marked C. 9. In No. 1, needle 1 was mounted and used throughout, the spare needle 2 being used as a deflector. The index correction for 1 was determined at the Magnetic Observatory at the Cape, both before and after the Expedition, by comparing the inclination with the face of the instrument west (that being the way the observations were taken on board) with the mean monthly inclination shown by the observatory needles. The following are the observations with the deflectors at $40^\circ$ from the apparent dip: November 10, 1844, needle 1, face west $-53^\circ 39'$; correction $+8'$ November 10, 1844, needle 1, face east $-53^\circ 59'$; correction $+28'$ November 21, 1844, needle 1, face west $-53^\circ 38'$; correction $+7'$ November 21, 1844, needle 1, face east $-53^\circ 58'$; correction $+27'$ The mean monthly inclination being $-53^\circ 31'$. "After the 13th of January it was found more convenient to adjust the deflectors at the apparent dip, and make the same observations serve both for dip and intensity. The index corrections to be applied in this case are given by the following observations: | Date | Observed Inclination.—Face West. | True Inclination. | Index correction. | |------------|----------------------------------|-------------------|-------------------| | | Direct. | Def. N. | Def. S. | Def. N and S. | Mean. | | | | 1844. | | | | | | | | | December 1 | $-53^\circ 52'$ | $-53^\circ 21'$ | $-53^\circ 44'$ | $-53^\circ 39'$ | $-53^\circ 39'$ | $-53^\circ 31'$ | $+07$ | | December 5 | $-53^\circ 49'$ | $-53^\circ 20'$ | $-53^\circ 43'$ | $-53^\circ 38'$ | $-53^\circ 38'$ | | | | 1845. | | | | | | | | | June 30 | $-54^\circ 12'$ | $-53^\circ 13'$ | $-53^\circ 46'$ | $-53^\circ 51'$ | $-53^\circ 45'$ | $-53^\circ 25'$ | $+19$ | | July 2 | $-54^\circ 08'$ | $-53^\circ 15'$ | $-53^\circ 46'$ | $-53^\circ 43'$ | $-53^\circ 43'$ | | | | Mean | $-54^\circ 01'$ | $-53^\circ 17'$ | $-53^\circ 45'$ | $-53^\circ 43'$ | $-53^\circ 41'$ | $-53^\circ 28'$ | $+13$ | "Magnets N and S are the small magnets belonging to the apparatus used conjointly; deflector N and deflector S are the respective poles of the spare needle. \(+13'\) has been applied in all cases except when only magnets N and S have been used, in which case \(+24'\) has been used, that being the mean correction for direct and magnets N and S. "For the index corrections for needle A of C. 9, we have only an observation in Simon's Bay, Cape of Good Hope, before starting. Needle A was used from the Cape to King George's Sound, and was observed on shore at King George's Sound on the 7th of April. On the 10th it was found, from the discordance of the observations, that its axle had been damaged since the observations on the 7th, it was therefore taken out and needle B mounted in its place. The instrument had a third needle C which was used as a deflector. The small magnets were also used, both conjointly and separately. The observation in Simon's Bay gives, For C. 9, needle A . . . . . . . . . . \(-53^\circ 24'\) Index correction \(-26'\). Corrected inclination, needle 1 . . . . \(-53^\circ 50'\) This correction has been applied to all observations made with needle A of C. 9. For the correction of needle B, we have a comparison at the Cape of Good Hope after the return of the Expedition, and also at Woolwich, in January 1846. All observations with this instrument were taken with the face east. "The following are the observations at the Cape: | Date | Observed Inclination.—Face East. | True Inclination. | Index correction. | |------------|----------------------------------|-------------------|------------------| | | Direct. | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | Mean. | | | 1845. | | | | | | | | | | June 30. | \(-53^\circ 56'\) | \(-54^\circ 15'\) | \(-52^\circ 47'\) | \(-54^\circ 06'\) | \(-53^\circ 29'\) | \(-53^\circ 23'\) | \(-53^\circ 40'\) | \(-53^\circ 25'\) | \(+15\) | | July 2. | \(-53^\circ 41'\) | \(-54^\circ 11'\) | \(-52^\circ 55'\) | \(-54^\circ 15'\) | \(-53^\circ 49'\) | \(-53^\circ 41'\) | \(-53^\circ 45'\) | \(-53^\circ 25'\) | \(+20\) | | Mean... | \(-53^\circ 48'\) | \(-54^\circ 13'\) | \(-52^\circ 51'\) | \(-54^\circ 10'\) | \(-53^\circ 39'\) | \(-53^\circ 32'\) | \(-53^\circ 43'\) | \(-53^\circ 25'\) | \(+18\) | "And at Woolwich: | Date | Observed Inclination.—Face East. | True Inclination. | Index correction. | |------------|----------------------------------|-------------------|------------------| | | Direct. | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | Mean. | | | 1846. | | | | | | | | | | Jan. 13. | \(+68^\circ 58'\) | \(+68^\circ 02'\) | \(+68^\circ 37'\) | \(+68^\circ 24'\) | \(+68^\circ 32'\) | \(+68^\circ 30'\) | \(+68^\circ 31'\) | \(+68^\circ 58'\) | \(+22\) | | Jan. 15. | \(+68^\circ 56'\) | \(+68^\circ 21'\) | \(+68^\circ 52'\) | \(+68^\circ 45'\) | \(+68^\circ 35'\) | \(+68^\circ 34'\) | \(+68^\circ 41'\) | \(+68^\circ 58'\) | \(+22\) | | Mean... | \(+68^\circ 57'\) | \(+68^\circ 12'\) | \(+68^\circ 44'\) | \(+68^\circ 35'\) | \(+68^\circ 33'\) | \(+68^\circ 32'\) | \(+68^\circ 36'\) | \(+68^\circ 58'\) | \(+22\) | "The index correction obtained at the Cape has been used for all the observations taken with this needle." "3. Elements of Calculation of the Intensity Observations. "For the observations with this instrument, the Cape of Good Hope has been taken as a base station, the intensity having been observed there both before and after the Expedition, so that any change in the magnetism of the deflectors or needles can be detected. "The intensity at Woolwich being assumed =1·372, it is necessary to get the corresponding intensity at the Cape. This can be got independent of the dipping-needles, by means of the absolute horizontal intensity and inclination observed at each station. "The value of the horizontal intensity at the Cape is given as follows by observations made at the observatory in February, March, April and May 1845: "Observations of the Absolute Horizontal Intensity, at the Magnetic Observatory, Cape of Good Hope, 1845. Bar. A. 21. Suspended . . . length 3·00 inch . . . \( \frac{H}{F} = 1·00084 \). Bar. V. Deflecting . . . length 3·67 inch . . . \( q = 0·00008 \) . . . \( \log \pi^2 \cdot k = 1·57254 \). | Date | Angles of Deflection. | Corrected time of vibration. | Temperature during | Bifilar readings at 60 during | Results. | |----------|-----------------------|------------------------------|--------------------|-------------------------------|---------| | | Dist. 1·2 ft. | Dist. 1·3 ft. | Deflection. | Vibration. | Deflection. | Vibration. | m. | X. | | Feb. 10, 11, 12. | 6 05·1 | 4 47·5 | 4·4970 | 71·4 | 71·7 | Scale dir. | Scale dir. | 0·4118 | 4·488 | | Mar. 10, 11, 12. | 6 01·1 | 4 44·0 | 4·5310 | 71·4 | 71·9 | 185·9 | 185·8 | 0·4064 | 4·480 | | Apr. 13, 14, 15. | 5 57·5 | 4 41·2 | 4·5570 | 62·9 | 62·6 | 176·9 | 177·4 | 0·4019 | 4·478 | | May 14, 15, 16. | 5 55·5 | 4 39·2 | 4·5650 | 60·7 | 59·9 | 177·2 | 177·5 | 0·4001 | 4·482 | "The value of \( k \) is obtained by means of two cylindrical weights in the usual manner; the value employed is the mean of several determinations. Bifilar magnetometer \( k = 0·00218, q = 0·00218 \). Increase of reading denotes increase of force. Whence \( X = 4·482, \theta \) being = −53° 25′ 5″. "The corresponding values at Woolwich are \( X = *3·7284, \theta \) being = +68° 57′ 9″. "From these values of \( X \) and \( \theta \), we obtain the relative value of the intensity at the Cape (that at Woolwich being 1·372), \( I = 0·993 \). "The relative intensity given by the needles of No. 1, from observations made at Woolwich and the Cape and given in the sequel, are as follows: Needle 1. \( \begin{cases} \text{Weight 1 gr. } I = 0·996 \\ \text{Weight 2 grs. } I = 1·017 \end{cases} \) 1·006. Needle 2. \( \begin{cases} \text{Weight 1 gr. } I = 0·994 \\ \text{Weight 2 grs. } I = 1·006 \end{cases} \) 1·000. * Contributions, No. VII.; Philosophical Transactions, 1846, p. 246. "The value of I at the Cape has therefore been assumed provisionally as unity; subject to future correction should any appear to be required. "The spare needle 2 was always used as a deflector; the two small magnets were used conjointly only with this apparatus. "Tables of equivalent weights were made at the Cape both before and after the Expedition, according to the method given in the instructions for the use of Mr. Fox's instrument. The following Table contains the mean of the two series. | Def. N. | Def. S. | Mag. N and S. | Def. N. (Continued.) | Def. S. (Continued.) | Mag. N and S. (Continued.) | |---------|---------|---------------|----------------------|----------------------|--------------------------| | v' | w' | v' | w' | v' | w' | | gr. | gr. | gr. | gr. | gr. | gr. | | 21° | 1·816 | 22° | 1·950 | 41° | 3·608 | | 22° | 1·835 | 23° | 1·964 | 42° | 3·522 | | 23° | 1·850 | 24° | 1·972 | 43° | 3·438 | | 24° | 1·861 | 25° | 1·977 | 44° | 3·350 | | 25° | 1·867 | 26° | 1·983 | 45° | 3·262 | | 26° | 1·868 | 27° | 1·980 | 46° | 3·179 | | 27° | 1·867 | 28° | 1·977 | 47° | 3·093 | | 28° | 1·866 | 29° | 1·968 | 48° | 3·013 | | 29° | 1·861 | 30° | 1·960 | 49° | 2·933 | | 30° | 1·858 | 31° | 1·946 | 50° | 2·853 | "With these values of w', and the following values of v and w, the values of I' have been calculated by the formula \[ I' = I \frac{\sin v \cdot w'}{\sin v' \cdot w} \text{ when deflectors are used, and } \] \[ I' = I \frac{\sin v}{\sin v'} \text{ when weights are used. } \] Values of v at the Cape of Good Hope. | Date. | Def. N. | Def. S. | Mag. N and S. | Weight 1 grain. | Weight 2 grains. | Weight 2½ grains. | |-------|---------|---------|---------------|-----------------|------------------|--------------------| | | w=1·721.| w=1·782.| w=2·337. | | | | | 1844. | | | | | | | | Dec. | 1° | 39° | 06° | 46° | 38° | 59° | | | | | | | | | | 1845. | | | | | | | | June | 30° | 39° | 31° | 40° | 39° | 58° | | July | 2° | 39° | 22° | 40° | 39° | 58° | | Mean..| 39° | 15° | 40° | 38° | 58° | 51° | "From this Table it is evident that, with the exception of magnets N and S, the needles preserved their magnetism throughout the voyage. Magnets N and S lost magnetism to the amount of '033. The mean of the four observations have been taken; the early intensities by this method will therefore be rather too small, the latter ones rather too great." "The formulae for calculation are as follows: Def. N. . . . . . . . . . $I' = \cdot3677 \text{ cosec } v' \cdot w'$. Def. S. . . . . . . . . . $I' = \cdot3654 \text{ cosec } v' \cdot w'$. Mag. N and S. . . . . . $I' = \cdot3659 \text{ cosec } v' \cdot w'$. Weight 1 grain . . . . . $I' = \cdot3698 \text{ cosec } v' \cdot w'$. Weight 2 grains . . . . . $I' = \cdot7264 \text{ cosec } v' \cdot w'$. Weight 2½ grains . . . . . $I' = \cdot9094 \text{ cosec } v' \cdot w'$. "Fox C. 9.—The values of the intensity at the Cape by the observations before and after the Expedition, by Fox, No. 1, are: Before . . . . . . . . $I = 0\cdot999$ After . . . . . . . . $I = 1\cdot001$ diff. '002. "These values agreeing so closely, we may assume that the intensity at King George's Sound with this apparatus will be very near the truth, and that King George's Sound may therefore be taken as a base station for needle A of C. 9, which was not observed at the Cape before our departure. The intensities were observed with needle A mounted, from the Cape to King George's Sound, when the needle got unfortunately damaged, and it was necessary to replace it with needle B: one day's observations had however been made before the accident, and these observations serve for calculating the intensities taken on the voyage, assuming the intensity at King George's Sound to be that given by the other apparatus, viz. 1·688. "The same deflectors and weights were used throughout; the spare needle C as a deflector, the two small magnets both conjointly and separately. "Tables of equivalent weights for these deflectors, with needle A mounted, were obtained in the same way as in the case of the other apparatus. They are as follows: | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | |---------|---------|---------------|---------|---------| | $v'$ | $w'$ | $v'$ | $w'$ | $v'$ | $w'$ | | grs. | grs. | grs. | grs. | grs. | | 50 | 2·175 | 50 | 2·206 | 70 | 2·625 | 50 | 1·578 | 50 | 1·975 | | 49 | 2·200 | 49 | 2·247 | 69 | 2·675 | 49 | 2·028 | 49 | 2·025 | | 48 | 2·225 | 48 | 2·288 | 68 | 2·725 | 48 | 2·078 | 48 | 2·075 | | 47 | 2·263 | 47 | 2·323 | 67 | 2·775 | 47 | 2·130 | 47 | 2·125 | | 46 | 2·300 | 46 | 2·357 | 66 | 2·825 | 46 | 2·182 | 46 | 2·175 | | 45 | 2·338 | 45 | 2·388 | 65 | 2·875 | 45 | 2·235 | 45 | 2·240 | | 44 | 2·375 | 44 | 2·419 | 64 | 2·925 | 44 | 2·288 | 44 | 2·304 | | 43 | 2·413 | 43 | 2·460 | 63 | 2·982 | 43 | 2·341 | 43 | 2·368 | | 42 | 2·450 | 42 | 2·500 | 62 | 3·038 | 42 | 2·394 | 42 | 2·433 | | 41 | 2·488 | 41 | 2·538 | 61 | 3·094 | 41 | 2·447 | 41 | 2·498 | | 40 | 2·525 | 40 | 2·575 | 60 | 3·150 | 40 | 2·500 | 40 | 2·563 | | 39 | 2·565 | 39 | 2·615 | 59 | 3·222 | 39 | 2·570 | 39 | 2·623 | | 38 | 2·605 | 38 | 2·655 | 58 | 3·294 | 38 | 2·640 | 38 | 2·683 | | 37 | 2·645 | 37 | 2·695 | 57 | 3·365 | 37 | 2·710 | 37 | 2·743 | | 36 | 2·685 | 36 | 2·735 | 56 | 3·436 | 36 | 2·780 | 36 | 2·803 | | 35 | 2·725 | 35 | 2·775 | 55 | 3·507 | 35 | 2·850 | 35 | 2·863 | | 34 | 2·755 | 34 | 2·806 | 54 | 3·595 | 34 | 2·900 | 34 | 2·937 | | 33 | 2·785 | 33 | 2·837 | 53 | 3·683 | 33 | 2·950 | 33 | 3·011 | | 32 | 2·815 | 32 | 2·869 | 52 | 3·770 | 32 | 3·000 | 32 | 3·085 | | 31 | 2·845 | 31 | 2·901 | 51 | 3·857 | 31 | 3·050 | 31 | 3·158 | | 30 | 2·875 | 30 | 2·932 | 50 | 3·944 | 30 | 3·100 | 30 | 3·232 | | 29 | 2·900 | 29 | 2·954 | 49 | 4·047 | | | | | | 28 | 2·925 | 28 | 2·975 | 48 | 4·150 | | | | | "The angles of deflection observed at King George's Sound are as follows: | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | Weight 1 grain | Weight 1½ grain | Weight 2 grains | Weight 2½ grains | Weight 3 grains | |---------|---------|---------------|---------|---------|----------------|-----------------|----------------|-----------------|----------------| | 33° 11' | 33° 32' | 50° 24' | 34° 30' | 34° 34' | 10° 44' | 17° 16' | 22° 55' | 28° 18' | 35° 10' | Employing the values of \( v \) and \( w \) (I being = 1·688), we get formulae for calculating the intensities, viz.— \[ \begin{align*} \text{Def. N} & : I' = 0·3325 \cos ec v' \cdot w' \\ \text{Def. S} & : I' = 0·3306 \cos ec v' \cdot w' \\ \text{Mag. N and S} & : I' = 0·3327 \cos ec v' \cdot w' \\ \text{Mag. N} & : I' = 0·3326 \cos ec v' \cdot w' \\ \text{Mag. S} & : I' = 0·3308 \cos ec v' \cdot w' \end{align*} \] Comparing observations made at sea near the Cape with those given by the other needle, the deflectors of this apparatus do not appear to have lost magnetism. "From King George's Sound to the Cape, needle B was mounted, the same deflectors and weights being used as with needle A. The Cape of Good Hope has been taken as the base station in this case, the intensity having been observed there on the return of the Expedition. "The table of equivalent weights is given below. | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | |---------|---------|---------------|---------|---------| | \( v' \) | \( w' \) | \( v' \) | \( w' \) | \( v' \) | \( w' \) | \( v' \) | \( w' \) | \( v' \) | \( w' \) | | 29° | 1·794 | 35° | 2·104 | 50° | 2·763 | 31° | 1·891 | 36° | 2·174 | | 30° | 1·782 | 36° | 2·076 | 51° | 2·701 | 32° | 1·862 | 37° | 2·122 | | 31° | 1·765 | 37° | 2·046 | 52° | 2·638 | 33° | 1·833 | 38° | 2·069 | | 32° | 1·748 | 38° | 2·015 | 53° | 2·576 | 34° | 1·804 | 39° | 2·012 | | 33° | 1·734 | 39° | 1·986 | 54° | 2·513 | 35° | 1·773 | 40° | 1·954 | | 34° | 1·719 | 40° | 1·956 | 55° | 2·457 | 36° | 1·741 | 41° | 1·903 | | 35° | 1·697 | 41° | 1·927 | 56° | 2·401 | 37° | 1·705 | 42° | 1·851 | | 36° | 1·675 | 42° | 1·898 | 57° | 2·345 | 38° | 1·669 | 43° | 1·801 | | 37° | 1·657 | 43° | 1·865 | 58° | 2·288 | 39° | 1·635 | 44° | 1·751 | | 38° | 1·638 | 44° | 1·832 | 59° | 2·247 | 40° | 1·600 | 45° | 1·707 | | 39° | 1·619 | 45° | 1·799 | 60° | 2·203 | 41° | 1·563 | 46° | 1·663 | | 40° | 1·600 | 46° | 1·766 | 61° | 2·167 | 42° | 1·525 | 47° | 1·626 | | 41° | 1·582 | 47° | 1·740 | 62° | 2·110 | 43° | 1·494 | 48° | 1·588 | | 42° | 1·563 | 48° | 1·713 | 63° | 2·071 | 44° | 1·463 | | | | 43° | 1·541 | 49° | 1·684 | 64° | 2·032 | 45° | 1·443 | | | | 44° | 1·519 | 50° | 1·654 | 65° | 1·996 | | | | | | 45° | 1·491 | | | 66° | 1·960 | | | | | | | | 67° | | 1·927 | | | | | | "The following are the angles of deflection on three separate days at the Magnetic Observatory, Cape of Good Hope: | Def. N. | Def. S. | Mag. N and S. | Mag. N. | Mag. S. | Weight 1 grain | Weight 1½ grain | Weight 2 grains | |---------|---------|---------------|---------|---------|----------------|-----------------|----------------| | 44° 32' | 49° 48' | 66° 02' | 43° 21' | 47° 13' | 28° 00' | 44° 10' | 69° 31' | | 45° 00' | 49° 59' | 66° 20' | 43° 45' | 47° 23' | 28° 26' | 44° 16' | 69° 15' | | 44° 33' | 49° 42' | 66° 16' | 43° 15' | 47° 20' | 28° 13' | 44° 13' | 69° 23' | MDCCXLVI. "Assuming the intensity at the Cape as unity, we get the following formulæ for calculation:— Def. N . . . . . . . . . . $I' = \cdot4692 \text{ cosec } v' \cdot w'$. Def. S . . . . . . . . . . $I' = \cdot4606 \text{ cosec } v' \cdot w'$. Mag. N and S . . . . . . . $I' = \cdot4686 \text{ cosec } v' \cdot w'$. Mag. N . . . . . . . . . . $I' = \cdot4634 \text{ cosec } v' \cdot w'$. Mag. S . . . . . . . . . . $I' = \cdot4552 \text{ cosec } v' \cdot w'$. Weight 1 grain . . . . . . $I' = \cdot4728 \text{ cosec } v'$. Weight 1½ grain . . . . . $I' = \cdot6974 \text{ cosec } v'$. Weight 2 grains . . . . . $I' = \cdot9361 \text{ cosec } v'$. "The value of the intensity at King George's Sound by this needle is— By weights . . . . . . . . 1\cdot688. By deflectors . . . . . . . '1\cdot672. "The intensity by the other apparatus No. 1 is 1\cdot688. "At the Mauritius the intensity is— By weights . . . . . . . . 1\cdot156. By deflectors . . . . . . . 1\cdot155. And by the other instrument 1\cdot156. "It is therefore evident that needle B preserved its magnetism from King George's Sound to the Cape. Comparing the results with the deflectors with those of the other instrument, the deflectors do not appear to have lost magnetism; the difference at King George's Sound of \cdot01 arises probably from error of observation. As the results given by weights are the most accurate when the observations are made on land, they have been exclusively used in such cases; at sea both weights and deflectors have been used. "Besides the correction for the effect of the ship's iron, a second correction for the effect of temperature on the needle and deflectors is necessary. The observations have all been reduced to a common temperature of 60° by means of the formulæ $$c = I' \cdot q(t' - t),$$ $t$ being taken as 60° and $q$ being the coefficient for 1° of Fahr. Values of $q$ for each needle and deflector employed, were obtained at the Magnetic Observatory, Cape of Good Hope, in the usual manner. The following is an abstract of the observations: | Needle or deflector | Approximate distance | Total deflection in scale divisions | Mean alternation of temperature | No. of alternations | Corresponding mean difference of deflection | Corresponding bilhar correction in parts of force when + additive | Values of $q$ | |---------------------|----------------------|-----------------------------------|-------------------------------|-------------------|---------------------------------------------|-------------------------------------------------|-------------| | No. 1 | | | | | | | | | A. 1 | 3 ft. 0 in. | 497\cdot5 | 38\cdot35 | 5 | 1\cdot36 | +\cdot000046 | \cdot00072 | | A. 2 | 3 ft. 0 in. | 805\cdot2 | 38\cdot76 | 5 | 3\cdot88 | +\cdot000004 | \cdot00116 | | Def. N | 1 ft. 0 in. | 873\cdot3 | 40\cdot43 | 5 | 4\cdot33 | +\cdot000019 | \cdot00123 | | Def. S | 1 ft. 0 in. | 880\cdot5 | 40\cdot02 | 5 | 2\cdot82 | +\cdot000054 | \cdot00081 | | C. 9 | | | | | | | | | A. | 1 ft. 5 in. | 1019\cdot0 | 34\cdot68 | 3 | 4\cdot21 | -\cdot000070 | \cdot00117 | | B. | 1 ft. 5 in. | 1059\cdot5 | 43\cdot35 | 4 | 3\cdot18 | -\cdot000004 | \cdot00069 | | C. | 1 ft. 5 in. | 1065\cdot9 | 43\cdot46 | 5 | 3\cdot67 | +\cdot000008 | \cdot00079 | | Def. N | 1 ft. 0 in. | 1004\cdot8 | 45\cdot85 | 5 | 7\cdot08 | +\cdot000004 | \cdot00154 | | Def. S | 1 ft. 0 in. | 1021\cdot7 | 47\cdot38 | 5 | 6\cdot45 | -\cdot000024 | \cdot00133 | "From the values of \( q \) tables of corrections were formed; observing that when weights are used an increase of temperature gives an additive correction, and the contrary when the deflectors are used. As the values of \( q \) are small, and the greatest difference of temperature amounts only to 30°, the corrections are seldom of any importance; they have however always been applied. "Besides the observations made on board the Pagoda, others have been laid down on the maps, in order to assist in drawing the magnetic lines. A series of observations made by Lieut. Smith, R.N., between the Cape and Van Diemen Island, and another by Lieut. Dayman, R.N., between Van Diemen Island and the Cape (with the same instrument), have been laid down on the map of the Inclination. The same needles and deflectors were used in both cases. Lieut. Smith's observations are all taken with the face of the instrument east; those of Lieut. Dayman's with it both east and west. The following observations, made at the Ross Bank Observatory, Van Diemen Island, will serve to obtain the index corrections; the inclination by the observatory needles being \(-70^\circ 40'\). | Observer | Direct. | Def. N. | Def. S. | Def. N and S. | Mean. | Index correction. | Face of instrument. | |----------------|---------|---------|---------|---------------|-------|-------------------|---------------------| | Lieut. Smith | -71 39' | -71 25' | -71 19' | -71 36' | -71 28' | +48 | East | | Lieut. Dayman | -71 40' | -71 22' | -71 14' | ............. | -70 20' | -27 | West | "These corrections have been applied to all the observations made by Lieut. Smith*. "As no observations were made for local attraction, we can only obtain approximate corrections, by comparing observations made on or near the same spot with the ship's head on different points of the compass. In the series made by Lieut. Smith we have the following observations: | August 14. | August 18. | September 10. | September 13. | |------------|------------|---------------|---------------| | E. \( \frac{1}{2} \) s. | -68 09' | -67 28' | -72 41' | -72 02' | | S.E. by E. \( \frac{1}{2} \) E... | -68 06' | -67 32' | -73 03' | -72 09' | | S.S.E. | -68 02' | -67 38' | -72 20' | | "From these comparisons it would appear that the correction is very small, especially on the easterly points which were those generally observed upon; the observations have therefore been entered without any correction for the effect of the ship's iron. "With regard to those of Lieut. Dayman, there are two cases where observations have been taken on different days, but in nearly the same position, and with the * When observations have been made with the face both east and west, the correction becomes \(+10'\); when weights as well as deflectors are used for the inclination, the correction face east and west becomes \(-13'\); this has been applied to the observations made by Lieut. Dayman. ship's head on different points of the compass, and also some in very nearly the same geographical position as the Pagoda. Comparing these, it appears that the effect of the iron is nearly the same in both ships; the observations have consequently been corrected from the Table that was used for those taken on board the Pagoda. The following comparisons will show how near these corrections approach the truth. | Lat. | Long. | Inclination. | Ship's head. | Tabular corrections. | Corrected Inclination. | Observer. | Remarks. | |------|-------|--------------|--------------|---------------------|------------------------|-----------|----------| | -35°22' | 117°46' | -66°06' | S.½ E. N.N.W. | +0°58' | -65°08' | Lieut. DAYMAN. | Difference +6 | | -35°06' | 117°55' | -66°47' | N.W. | +1°31' | -65°16' | Lieut. CLERK. | Difference -32 | | -34°58' | 112°59' | -66°47' | W.N.W. | +1°12' | -64°44' | Lieut. DAYMAN. | Difference -13 | | -34°16' | 113°01' | -55°32' | S.W.½ W. | +0°18' | -56°43' | Lieut. CLERK. | Difference +23 | | -34°39' | 99°33' | -57°01' | N.by W.½ W. | +1°19' | -57°06' | Lieut. CLERK. | Difference +18 | | -35°07' | 20°46' | -56°09' | S.S.W. | -0°18' | -67°03' | Lieut. DAYMAN. | January 9, 1845. | | -36°42' | 118°35' | -66°45' | N.by W. | +1°22' | -67°19' | Lieut. DAYMAN. | January 10, 1845. | | -36°58' | 117°38' | -68°41' | S.S.W. | -0°18' | -66°27' | Lieut. DAYMAN. | January 11, 1845. | | -36°06' | 116°42' | -66°09' | N.W. | +1°31' | -66°43' | Lieut. DAYMAN. | January 13, 1845. | "The observations thus corrected have been entered in the chart. The lines on the chart are drawn by estimation, so as to conform as nearly as possible with the observations: some part of the lines laid down by Lieut.-Colonel Sabine (in No. V. of the Contributions) from Sir James C. Ross's observations have been dotted in, to show the agreement of the two series. "In the Chart of 'Magnetic Declinations,' a series of observations made on board the 'Erebus' by Sir James C. Ross, between the Cape of Good Hope and Hobarton, have been laid down. These observations have been corrected for index error and local attraction, in the same way as the other observations during the Antarctic Expedition, the same constants being used. "In the chart of intensities, Sir James C. Ross's observations between the Cape of Good Hope and Hobarton have also been entered. These observations are contained in Lieut.-Colonel Sabine's Contributions, No. III. and V. The Cape of Good Hope is the base station in this case; but the intensity there has been taken as 0·981; it is therefore necessary to reduce them to an intensity at the Cape = 1·0, in order that they may compare with the intensities taken on board the Pagoda; this is done by multiplying each of them by $\frac{0·981}{1·000} = 1·02$ nearly. The observations thus corrected are given in a table at the end of the 'Pagoda' observations, together with those of variation and inclination by Sir J. Ross, and the inclinations and intensities by Lieuts. Smith and Dayman. "In calculating the intensities observed by Lieut. Smith, Hobarton has been taken as the base station, and the results by weights only used. The same has been done..." Observations of the Declination. L.M. HIRED BARK, PAGODA, January and June, 1845. H.M.S. Eulais, in 1840. Note except when the - Sign is prefixed. Observations MAGNETIC INCLINATION MADE ON BOARD H. M. BARONET by Lieut. T. E. L. Moore, R. Navy and also in 1840 by Sir James and in 1844 by Lieut. AND IN 1844-1845 BY LIEUT. with the series by Lieut. Dayman, the weights of two grains and three grains having been observed daily; the following observations with weights made at the observatory, Hobarton, give the formulæ for calculation: (I.) Lieut. Smith's. \[ \begin{align*} 2 \text{ grains } v &= 10^{\circ} 33' \\ 3 \text{ grains } v &= 16^{\circ} 05' \end{align*} \] \[I = 1.80; I' = 0.3296 \text{ cosec } v'\] \[I = 1.80; I' = 0.4987 \text{ cosec } v'\] (II.) Lieut. Dayman's. \[ \begin{align*} 1 \text{ grain } v &= 5^{\circ} 19' \\ 2 \text{ grains } v &= 10^{\circ} 35' \\ 3 \text{ grains } v &= 16^{\circ} 20' \\ 4 \text{ grains } v &= 21^{\circ} 50' \\ 5 \text{ grains } v &= 27^{\circ} 41' \\ 6 \text{ grains } v &= 34^{\circ} 08' \end{align*} \] From these we obtain the following values of \(v\) for 2 and 3 grains; viz.— for 2 grains \(v = 10^{\circ} 43'\) for 3 grains \(v = 16^{\circ} 11'\) Hence for 2 grains \(I' = 0.3347 \text{ cosec } v'\) for 3 grains \(I' = 0.5017 \text{ cosec } v'\) "In correcting these observations the same plan has been pursued as with the dip observations. As Lieut. Smith's observations required no correction in the latter case, so none has been applied to the intensities; and Lieut. Dayman's have been corrected from the same table as was used for the 'Pagoda' observations. No corrections have been applied for the effect of temperature; but they are probably so small as not to affect the results." Observations of the Declination made on board Her Majesty's hired Bark "Pagoda," from the 10th of January to the 23rd of June 1845. The Observers are distinguished as follows:—M. Lieut. Moore; B. Mr. Bodie, Master; Cl. Lieut. Clerk; Cm. Mr. Comber, Mate; T. Mr. Tufnell, and Bn. Mr. Burdon, Midshipmen. West Declination characterized by the sign +. | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|---------| | 1845. | | | | | | | | | | | Jan. 10 A.M. | -34° 42' 16" 36' | M. | +29° 04' | w. | +16 | +47 | +30° 07' | Card A. Index correction made by observations made at the observatory, Cape of Good Hope. | | | -34° 42' 17" 36' | M. | +29° 12' | w. | +16 | +47 | +30° 15' | +29° 51 | | | -34° 42' 17" 36' | Cl. | +28° 50' | w. ½ s. | +15 | +47 | +29° 52' | +29° 09 | | | -34° 42' 17" 36' | Cl. | +28° 06' | w. | +16 | +47 | +28° 29' | +28° 39 | | 11 A.M. | -35° 26' 15" 08' | Cl. | +27° 31' | w.s.w. | +11 | +47 | +28° 29' | +28° 39 | | | -35° 26' 15" 08' | M. | +27° 51' | w.s.w. | +11 | +47 | +28° 49' | +28° 39 | | | -35° 26' 15" 08' | Cl. | +27° 43' | w.s.w. | +11 | +47 | +28° 41' | +28° 39 | | | -35° 26' 15" 08' | M. | +27° 41' | s.w.byw.½w. | +10 | +47 | +28° 38' | +28° 39 | | 12 A.M. | -35° 17' 14" 00' | B. | +25° 45' | w. by n. | +03 | +47 | +26° 35' | +27° 15 | | | -35° 17' 14" 00' | B. | +26° 23' | w. by n. | +03 | +47 | +27° 13' | +27° 15 | | | -35° 17' 14" 00' | B. | +27° 06' | w. by n. | +03 | +47 | +27° 56' | +27° 15 | | 13 A.M. | -35° 10' 13" 25' | B. | +24° 37' | s.w. by w. | +07 | +47 | +25° 31' | +25° 40 | | | -35° 10' 13" 25' | B. | +25° 04' | s.w. by w. | +07 | +47 | +25° 58' | +25° 40 | | | -35° 10' 13" 25' | B. | +24° 38' | s.w. by w. | +07 | +47 | +25° 32' | +25° 40 | | 15 P.M. | -38° 43' 14" 25' | M. | +24° 22' | s.s.w.½ w. | +00 | +47 | +25° 09' | +25° 09 | | 16 A.M. | -39° 00' 14" 38' | M. | +27° 13' | s.w.byw.½w. | +18 | +47 | +28° 18' | +28° 20 | | | -39° 01' 14" 45' | Cm. | +25° 44' | s.w. by s. | +06 | +47 | +26° 37' | +28° 20 | | 16 P.M. | -39° 12' 14" 42' | M. | +27° 48' | s.w. by s. | +06 | +47 | +28° 41' | +28° 20 | | | -39° 20' 14" 12' | M. | +28° 25' | s.w. by s. | +06 | +47 | +29° 18' | +28° 20 | | | -39° 22' 14" 25' | B. | +27° 10' | s.w. by s. | +06 | +47 | +28° 03' | +28° 20 | | | -39° 22' 14" 25' | B. | +28° 28' | s.w. by s. | +06 | +47 | +29° 21' | +28° 20 | | | -39° 22' 14" 25' | B. | +27° 01' | s.w. by s. | +06 | +47 | +27° 54' | +28° 20 | | | -39° 22' 14" 25' | B. | +27° 49' | s.w. by s. | +06 | +47 | +28° 42' | +28° 20 | | | -39° 22' 14" 25' | B. | +27° 28' | s.w. by s. | +06 | +47 | +28° 21' | +28° 20 | | | -39° 22' 14" 25' | B. | +28° 28' | s.w. by s. | +06 | +47 | +29° 21' | +28° 20 | | | -39° 22' 14" 25' | Cm. | +26° 26' | s.w. by s. | +06 | +47 | +27° 19' | +28° 20 | | 17 A.M. | -40° 08' 14" 32' | B. | +26° 17' | s.w. by w. | +16 | +47 | +27° 20' | +27° 40 | | | -40° 08' 14" 32' | B. | +25° 18' | s.w. by w. | +16 | +47 | +26° 21' | +27° 40 | | | -40° 09' 14" 33' | M. | +25° 33' | s.w. by w. | +16 | +47 | +26° 36' | +27° 40 | | | -40° 12' 14" 39' | Cl. | +26° 56' | s.w. by w. | +16 | +47 | +27° 59' | +27° 40 | | | -40° 16' 14" 36' | T. | +27° 34' | s.w. by w. | +16 | +47 | +28° 37' | +27° 40 | | | -40° 18' 14" 35' | T. | +26° 54' | s.w. by w. | +16 | +47 | +27° 57' | +27° 40 | | | -40° 15' 14" 37' | Cm. | +27° 04' | s.w. by w. | +16 | +47 | +28° 07' | +27° 40 | | | -40° 15' 14" 37' | Cm. | +27° 12' | s.w. by w. | +16 | +47 | +28° 15' | +27° 40 | | | -40° 14' 14" 37' | Cm. | +26° 00' | s.w. by w. | +16 | +47 | +27° 03' | +27° 40 | | | -40° 15' 14" 38' | T. | +26° 00' | s.w. by w. | +16 | +47 | +27° 03' | +27° 40 | | | -40° 24' 14" 32' | M. | +27° 57' | s.w. by w. | +16 | +47 | +29° 00' | +27° 40 | | 19 A.M. | -44° 45' 13" 19' | Cl. | +25° 09' | s.s.w.½ w. | +04 | +47 | +26° 00' | +26° 34 | | | -44° 45' 13" 19' | M. | +23° 05' | s.s.w.½ w. | +04 | +47 | +23° 56' | +26° 34 | | | -44° 45' 13" 19' | B. | +27° 40' | s.s.w. | +02 | +47 | +28° 29' | +26° 34 | | | -44° 45' 13" 19' | Cm. | +27° 00' | s.s.w. | +02 | +47 | +27° 27' | +26° 34 | | 20 A.M. | -46° 24' 13" 34' | B. | +24° 51' | s.w. by w. | +19 | +47 | +25° 57' | +25° 54 | | | -46° 24' 13" 34' | B. | +24° 31' | s.w. by w. | +19 | +47 | +25° 37' | +25° 54 | | | -46° 24' 13" 34' | B. | +25° 02' | s.w. by w. | +19 | +47 | +26° 08' | +25° 54 | | | -48° 27' 10" 51' | B. | +23° 08' | s.w. by s. | +12 | +47 | +24° 07' | +24° 50 | | | -48° 27' 10" 51' | B. | +22° 41' | s.w. by s. | +12 | +47 | +23° 40' | +24° 50 | | | -48° 27' 10" 51' | M. | +24° 40' | s.w. by s. | +12 | +47 | +25° 39' | +24° 50 | | | -48° 27' 10" 51' | Cl. | +24° 54' | s.w. by s. | +12 | +47 | +25° 53' | +24° 50 | Ship very unsteady; heavy sea. ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|---------------------|-------------|-------------|--------------|----------------------|---------| | **1845.** | | | | | | | | | | | Jan. 23 A.M. | -50° 30' | 10° 25' | M. | +22° 30' s.w. ½ s. | | | +16° 47' | +23° 33' | | | | -50° 31' | 10° 25' | Cm. | +23° 38' s.w. by s. | | | +16° 47' | +24° 41' | | | | -50° 31' | 10° 25' | Cl. | +24° 27' s.w. ½ s. | | | +16° 47' | +25° 35' | | | 23 P.M. | -50° 48' | 10° 17' | M. | +23° 18' s.w.byw. ½ w.| -57° 11' | | +16° 47' | +24° 21' | | | | -50° 50' | 10° 20' | Cl. | +21° 09' s.w. by w. | | | +16° 47' | +22° 12' | | | | -50° 58' | 10° 10' | M. | +23° 14' s.w. | | | +16° 47' | +24° 17' | | | | -50° 58' | 10° 10' | Cl. | +22° 26' s.w. | | | +16° 47' | +23° 29' | | | | -50° 58' | 10° 09' | T. | +22° 15' s.w. | | | +16° 47' | +23° 18' | | | 24 A.M. | -51° 45' | 9° 34' | B. | +23° 11' s.w. by w. | -57° 39' | | +25° 47' | +24° 23' | | | | -51° 45' | 9° 34' | M. | +20° 06' s.w. by w. | | | +25° 47' | +21° 18' | | | | -51° 45' | 9° 34' | Cl. | +20° 58' s.w. by w. | | | +25° 47' | +22° 10' | | | 24 P.M. | -51° 47' | 9° 34' | Cm. | +22° 00' s.w.byw. ½ w.| -57° 39' | | +29° 47' | +23° 16' | | | | -51° 47' | 9° 34' | Cm. | +23° 50' s.w.byw. ½ w.| | | +29° 47' | +25° 06' | | | | -51° 47' | 9° 40' | Bn. | +22° 50' s.w.byw. ½ w.| | | +29° 47' | +25° 20' | | | | -51° 45' | 9° 34' | B. | +23° 11' s.w. by w. | | | +25° 47' | +24° 06' | | | | -51° 45' | 9° 34' | M. | +20° 06' s.w. by w. | | | +25° 47' | +21° 18' | | | | -51° 45' | 9° 34' | Cl. | +20° 58' s.w. by w. | | | +25° 47' | +22° 10' | | | | -51° 49' | 9° 32' | Cl. | +22° 46' s.w. by w. | -57° 39' | | +25° 47' | +23° 58' | Card A. | | | -51° 49' | 9° 32' | B. | +21° 49' s.w. by w. | | | +25° 47' | +23° 01' | | | | -51° 50' | 9° 32' | B. | +22° 53' s.w.byw. ½ w.| | | +29° 47' | +24° 09' | | | | -51° 50' | 9° 31' | Cl. | +22° 18' s.w.byw. ½ w.| | | +29° 47' | +23° 34' | | | | -51° 50' | 9° 31' | M. | +22° 49' s.w.byw. ½ w.| | | +29° 47' | +24° 05' | | | | -51° 50' | 9° 31' | Cl. | +23° 08' s.w.byw. ½ w.| | | +29° 47' | +24° 24' | | | | -51° 50' | 9° 31' | T. | +22° 36' s.w.byw. ½ w.| -57° 39' | | +29° 47' | +23° 52' | | | 25 A.M. | -52° 45' | 7° 53' | M. | +22° 51' s.w.byw. ½ w.| -57° 14' | | +25° 47' | +23° 37' | | | | -53° 00' | 7° 53' | Cm. | +22° 50' s.w. by w. | | | +25° 47' | +24° 02' | | | | -53° 00' | 7° 53' | Cm. | +22° 06' s.w. by w. | | | +25° 47' | +23° 18' | | | | -53° 00' | 7° 53' | Cm. | +22° 54' s.w. by w. | | | +25° 47' | +24° 06' | | | 26 A.M. | -53° 52' | 6° 16' | M. | +19° 49' w. ½ N. | -57° 00' | | +36° 52' | +21° 17' | | | | -53° 52' | 6° 16' | B. | +20° 18' w. by s. | | | +36° 52' | +21° 46' | | | | -53° 52' | 6° 16' | Cl. | +20° 56' w. by s. | | | +33° 52' | +22° 21' | | | | -53° 52' | 6° 16' | Cl. | +20° 24' w. by s. | | | +33° 52' | +21° 49' | | | | -53° 52' | 6° 16' | Cl. | +20° 36' w. by s. | | | +33° 52' | +22° 01' | | | | -53° 52' | 6° 16' | Cl. | +20° 36' w. by s. | | | +33° 52' | +22° 53' | | | | -53° 55' | 6° 06' | B. | +21° 08' E. ½ S. | | | +33° 52' | +22° 01' | | | | -53° 55' | 6° 06' | Cl. | +21° 38' E. ½ S. | | | +1° 22° | +20° 38' | | | | -53° 55' | 6° 06' | Cl. | +20° 54' N.E. | | | +1° 22° | +21° 08' | | | | -53° 55' | 6° 06' | M. | +20° 53' N. | | | +1° 22° | +20° 54' | | | | -53° 55' | 6° 06' | M. | +22° 03' E. ½ S. | | | +1° 22° | +21° 33' | | | 27 P.M. | -55° 13' | 5° 57' | M. | +19° 56' s.w.byw. ½ s.| -57° 49' | | +12° 52' | +22° 16' | | | | -55° 30' | 5° 54' | M. | +21° 14' s.w.byw. ½ w.| | | +12° 52' | +20° 52' | | | | -55° 45' | 5° 50' | M. | +19° 48' s.w.by s. | | | +19° 52' | +17° 18' | | | 29 A.M. | -58° 53' | 4° 19' | Cl. | +16° 07' s.w. ½ s. | -59° 00' | | +19° 52' | +14° 56' | | | | -58° 53' | 4° 19' | B. | +13° 45' s.w.by s. | | | +19° 52' | +16° 47' | | | | -59° 13' | 4° 00' | M. | +15° 36' s.w. ½ s. | | | +19° 52' | +20° 59' | | | | -59° 13' | 4° 00' | Cl. | +19° 48' s.w. ½ s. | | | +19° 52' | +21° 40' | | | 31 A.M. | -60° 48' | 8° 18' | B. | +22° 35' E. ½ S. | | | +48° 52' | +20° 36' | | | | -61° 03' | 9° 05' | Cm. | +20° 32' S.E. by s. | | | +48° 52' | +19° 31' | | | | -61° 08' | 9° 05' | M. | +19° 27' S.E. by s. | | | +48° 52' | +19° 47' | | | | -61° 08' | 9° 05' | Cl. | +19° 43' S.E. by s. | | | +1° 01° | +20° 22' | Unsteady.| | 31 P.M. | -61° 15' | 9° 30' | Cl. | +20° 31' S.E. | -61° 30' | | +1° 01° | +20° 29' | | | | -61° 15' | 9° 30' | M. | +21° 08' S.E. | | | +1° 01° | +20° 59' | | | | -61° 20' | 10° 07' | M. | +21° 16' S.S.E. ½ E. | | | +1° 01° | +21° 37' | | | | -61° 20' | 10° 07' | Cl. | +20° 28' S.S.E. ½ E. | | | +1° 01° | +20° 49' | | | | -61° 20' | 10° 07' | Bn. | +19° 23' S.S.E. ½ E. | | | +1° 01° | +19° 44' | | | | -61° 20' | 10° 07' | Cl. | +19° 21' S.S.E. ½ E. | | | +1° 01° | +19° 42' | | | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|---------| | Feb. 1 A.M.| -61°55' | 12°26' | CL. | +22°15' | S.E. by s. | | | | | | | -62°06' | 12°45' | CM. | +23°40' | S.E. by s. | | | | | | | -62°06' | 12°55' | B. | +22°21' | S.E. by s. | | | | | | | -62°06' | 12°55' | CL. | +20°12' | S.E. | | | | | | 2 A.M. | -61°53' | 15°57' | B. | +22°55' | E.N.E. | | | | | | | -61°54' | 16°34' | M. | +25°19' | S.E. ½ E. | | | | | | | -61°54' | 16°38' | M. | +26°34' | S.E. ½ E. | | | | | | | -61°55' | 16°40' | T. | +23°04' | S.E. ½ E. | | | | | | | -61°54' | 16°42' | CL. | +21°28' | S.E. by E. | | | | | | | -61°54' | 16°57' | CL. | +21°36' | S.E. ½ E. | | | | | | | -61°54' | 16°57' | B. | +20°12' | S.E. ½ E. | | | | | | | -61°54' | 16°57' | BN. | +27°44' | S.E. ½ E. | | | | | | 3 A.M. | -61°49' | 19°15' | T. | +27°56' | E.S.E. | | | | | | | -61°49' | 19°15' | BN. | +25°32' | S.E.by E. ½ E. | | | | | | | -61°50' | 19°15' | CM. | +27°32' | S.E.by E. ½ E. | | | | | | | -61°50' | 19°06' | B. | +27°19' | E.S.E. | | | | | | | -61°50' | 19°12' | M. | +27°41' | E.S.E. | | | | | | | -61°50' | 19°13' | M. | +27°43' | E.S.E. | | | | | | | -61°50' | 19°14' | M. | +27°15' | E.S.E. | | | | | | | -61°50' | 19°13' | CL. | +27°56' | E.S.E. | | | | | | | -61°50' | 19°13' | CL. | +27°59' | E.S.E. | | | | | | | -61°50' | 19°13' | BN. | +27°32' | E.S.E. | | | | | | 3 P.M. | -61°50' | 19°14' | M. | +26°52' | N.E.by N. | | | | | | | -61°50' | 19°14' | CL. | +24°05' | N.W. ½ W. | | | | | | | -61°50' | 19°14' | CL. | +23°31' | W. by N. | | | | | | | -61°50' | 19°14' | CL. | +23°24' | W. by S. | | | | | | | -61°50' | 19°14' | CL. | +23°31' | W.S.W. | | | | | | | -61°50' | 19°14' | CL. | +24°37' | N.W. by W. | | | | | | | -61°50' | 19°14' | B. | +25°37' | N.W. | | | | | | | -61°50' | 19°14' | CL. | +24°52' | N.W. | | | | | | | -61°50' | 19°14' | CL. | +24°00' | W. by N. | | | | | | | -61°50' | 19°14' | M. | +24°06' | W. | | | | | | | -61°50' | 19°14' | M. | +23°51' | W.S.W. | | | | | | | -61°50' | 19°14' | CL. | +25°46' | S.W. | | | | | | | -61°50' | 19°14' | CL. | +23°53' | S.S.E. | | | | | | | -61°50' | 19°14' | CL. | +28°55' | S. ½ E. | | | | | | | -61°50' | 19°14' | M. | +25°55' | In the boat.| | | | | | | -61°50' | 19°14' | M. | +24°45' | s. by E. | | | | | | 4 A.M. | -62°00' | 20°55' | M. | +25°36' | S. ½ E. | | | | | | | -62°00' | 20°55' | M. | +26°09' | S. ½ E. | | | | | | | -62°00' | 20°37' | CL. | +26°59' | S. ½ E. | | | | | | | -62°05' | 20°58' | M. | +29°02' | S.S.E. ½ E. | | | | | | | -62°07' | 21°04' | M. | +27°14' | S.S.E. | | | | | | | -62°10' | 21°03' | CL. | +28°15' | S.S.E. | | | | | | | -62°10' | 21°03' | CL. | +28°16' | S.S.E. | | | | | | | -62°10' | 21°03' | BN. | +30°14' | S.S.E. | | | | | | | -62°10' | 21°03' | B. | +27°26' | S.S.E. | | | | | | 5 A.M. | -63°14' | 21°10' | M. | +29°01' | s. by E. | | | | | | | -63°18' | 21°10' | M. | +28°51' | s. by E. | | | | | | | -63°18' | 21°10' | CL. | +27°08' | S. ½ E. | | | | | | | -63°18' | 21°10' | BN. | +28°47' | S. ½ E. | | | | | | | -63°18' | 21°10' | T. | +28°08' | S.S.E. | | | | | | | -63°19' | 21°10' | M. | +28°14' | S.S.E. | | | | | * This observation is not much to be depended on, as the compass was very unsteady and difficult to observe. ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head. | Inclination. | Corrections. | Corrected Declination. | Remarks | |------------|------|-------|----------|----------------------|--------------|-------------|--------------|------------------------|---------| | **1845.** | | | | | | | | | | | Feb. 6 A.M.| -64° | 06' | B. | +28° 41' | S.S.E. | | | -42° +53' +28° 51' | | | | -64° | 18' | Cl. | +28° 29' | S.S.E. | | | -42° +52' +28° 39' | | | | -64° | 18' | Cl. | +29° 44' | S.S.E. | | | -42° +52' +29° 54' | | | | -64° | 20' | M. | +29° 57' | S.S.E. | | | -42° +52' +30° 07' | | | | -64° | 25' | M. | +28° 43' | S.S.E. | | | -48° +52' +28° 47' | +30° 24' Card steady. | | 6 P.M. | -64° | 35' | Cl. | +31° 43' | S.E.by S. | | | -66° 39' | | | | -64° | 38' | Cl. | +31° 22' | S.S.E. | | | -50° +52' +31° 45' | | | | -64° | 38' | Bn. | +32° 39' | S.S.E. | | | -42° +52' +31° 32' | | | | -64° | 25' | M. | +31° 06' | S.S.E. | | | -42° +52' +32° 49' | | | | -64° | 25' | M. | +32° 02' | S.E.by S. | | | -48° +52' +31° 10' | | | 7 A.M. | -65° | 30' | M. | +32° 02' | S.E.by S. | | | -1° 03' +52' +31° 51' | | | | -65° | 25' | B. | +32° 46' | S.S.E. | | | -42° +52' +32° 56' | | | | -65° | 16' | Cl. | +30° 41' | S.S.E. | | | -52° +52' +30° 41' | | | | -65° | 16' | Cl. | +31° 16' | S.S.E. | | | -52° +52' +31° 16' | | | | -65° | 16' | Bn. | +31° 51' | S.S.E. | | | -52° +52' +31° 51' | | | 7 P.M. | -66° | 02' | B. | +31° 12' | S.½ E. | | | -67° 28' | +31° 37' Compass steady. | | | -66° | 02' | Cl. | +30° 11' | S.½ E. | | | -18° +52' +30° 45' | | | | -66° | 02' | M. | +30° 25' | S.½ E. | | | -18° +52' +30° 59' | | | | -66° | 02' | B. | +31° 08' | S.½ E. | | | -18° +52' +31° 42' | | | | -66° | 02' | Bn. | +31° 00' | S.½ E. | | | -18° +52' +31° 34' | | | | -66° | 02' | Cl. | +31° 49' | S.½ E. | | | -18° +52' +32° 23' | | | 9 P.M. | -66° | 26' | Cl. | +36° 04' | S.E.by E. | | | -68° 49' | +35° 39' Steady. | | | -66° | 26' | Bn. | +35° 08' | S.E.by E. | | | -1° 08' +52' +35° 48' | | | | -66° | 26' | M. | +36° 34' | S.E.by E. | | | -1° 08' +52' +36° 18' | | | 10 A.M. | -66° | 43' | B. | +37° 20' | S.by W.½ W. | | | +32° +52' +38° 44' | | | | -66° | 43' | Cl. | +35° 26' | S.S.W. | | | +42° +52' +37° 00' | | | 10 P.M. | -67° | 03' | Cl. | +38° 33' | S.S.W.½ W. | | | -69° 22' | +37° 43' Steady. | | | -67° | 03' | Cl. | +35° 10' | S.S.W.½ W. | | | +52° +52' +36° 07' | | | | -67° | 03' | Cl. | +39° 35' | N.by W. | | | +52° +52' +36° 54' | | | 11 A.M. | -67° | 34' | Bn. | +40° 06' | E. | | | -2° 46' +52' +38° 12' | | | | -67° | 34' | Cl. | +40° 11' | E.by S. | | | -2° 30' +52' +38° 33' | | | | -67° | 34' | Cl. | +39° 26' | E.by S. | | | -2° 30' +52' +37° 48' | | | | -67° | 34' | Cl. | +36° 03' | S.W.by S. | | | -69° 38' | +38° 13' Card steady. | | | -67° | 34' | Cl. | +37° 37' | S. | | | -0° 2° +52' +38° 31' | | | | -67° | 34' | Cl. | +38° 57' | N.N.E. | | | -1° 40' +52' +38° 09' | | | | -67° | 38' | B. | +37° 49' | S.½ E. | | | -1° 15' +52' +38° 26' | | | 12 A.M. | -66° | 38' | B. | +37° 23' | N.by E. | | | -1° 20' +47' +36° 50' | | | | -66° | 38' | Cl. | +39° 04' | S.S.E. | | | -45° +47' +39° 06' | +37° 18' Card A. unsteady. | | | -66° | 47' | M. | +35° 56' | S.S.E. | | | -45° +47' +35° 58' | | | 13 A.M. | -67° | 06' | Cl. | +37° 48' | N.E.½ E. | | | -2° 20' +52' +36° 20' | | | | -67° | 06' | Cl. | +38° 57' | N.E.by E. | | | -2° 26' +52' +37° 23' | | | | -67° | 06' | T. | +39° 30' | N.E.by E. | | | -2° 26' +52' +37° 56' | +36° 59' Card J. steady. | | | -67° | 06' | Bn. | +38° 03' | N.E.by E. | | | -2° 26' +52' +36° 29' | | | | -67° | 06' | B. | +38° 25' | N.E.by E.½ E.| | | -2° 32' +52' +36° 45' | | | 14 A.M. | -67° | 01' | B. | +35° 53' | N.N.E. | | | -1° 35' +52' +35° 10' | | | | -67° | 01' | Cl. | +40° 02' | N.N.E.½ E. | | | -1° 41' +52' +39° 13' | | | 16 A.M. | -64° | 52' | M. | +36° 11' | S.by E. | | | -2° 22' +52' +36° 41' | | | | -64° | 52' | Cl. | +41° 36' | N.N.E. | | | -1° 37' +52' +40° 51' | | | 16 P.M. | -64° | 52' | Cl. | +35° 44' | S.E. | | | -2° 03' +52' +34° 55' | | | | -64° | 52' | T. | +36° 06' | E.S.E. | | | -1° 46' +52' +35° 37' | | | | -64° | 52' | Bn. | +36° 31' | S.E.by E. | | | -44° +52' +37° 08' | | | 17 P.M. | -64° | 52' | M. | +37° 00' | S.S.E. | | | -44° +52' +35° 36' | | | | -64° | 52' | Bn. | +35° 28' | S.S.E. | | | -44° +52' +37° 49' | | | | -64° | 52' | M. | +37° 41' | S.S.E. | | | -44° +52' +38° 28' | | | | -64° | 52' | Cl. | +38° 20' | S.S.E. | | | -1° 06' +52' +37° 40' | | | | -64° | 52' | Cl. | +37° 54' | S.E.by S. | | | -1° 06' +52' +34° 40' | | MDCCXLVI. ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|------------------| | **1845.** | | | | | | | | | | | Feb. 18 A.M. | -64° 22' 40" 49' | CL. | +38° 35' | s.by E.½ E. | -68° 40' | -32° +52' +38° 55' | +36° 32' | Very unsteady. | | | -64° 22' 40" 49' | B. | +34° 41' | N.by E.½ E. | -1° 24' +52' +34° 09' | +37° 34' | Very unsteady. | | 19 P.M. | -63° 58' 41" 25' | CL. | +38° 43' | S.E.by E.½ E. | -2° 04' +52' +37° 31' | +37° 34' | Very unsteady. | | | -63° 58' 41" 25' | BN. | +38° 20' | E.S.E. | -2° 15' +52' +36° 57' | +37° 34' | Very unsteady. | | | -63° 56' 42" 00' | BN. | +39° 52' | E.by S. | -2° 30' +52' +38° 14' | +37° 34' | Very unsteady. | | 20 A.M. | -63° 24' 44" 47' | B. | +40° 08' | S.E.by S. | -1° 08' +52' +39° 52' | +39° 39' | Unsteady. | | | -63° 24' 45" 32' | CL. | +41° 03' | S.E.by E.½ E. | -2° 04' +52' +39° 51' | +39° 39' | Unsteady. | | | -63° 22' 45" 32' | BN. | +42° 12' | S.E.by E.½ E. | -2° 04' +52' +41° 00' | +39° 39' | Unsteady. | | | -63° 22' 45" 32' | CM. | +39° 39' | S.E.by E.½ E. | -2° 04' +52' +38° 27' | +39° 39' | Unsteady. | | 20 P.M. | -63° 19' 45" 52' | M. | +39° 50' | S.E.by E. | -1° 54' +52' +38° 48' | +39° 39' | Unsteady. | | | -63° 19' 45" 52' | CL. | +40° 11' | S.E.by S. | -1° 08' +52' +39° 55' | +39° 39' | Unsteady. | | 21 A.M. | -63° 34' 46" 48' | M. | +39° 46' | E.by S.½ S. | -2° 28' +52' +38° 10' | +39° 39' | Card steady. | | | -63° 34' 46" 48' | CL. | +39° 00' | S.S.E. | -4° 99' +52' +39° 03' | +39° 39' | Card steady. | | | -63° 34' 46" 48' | CL. | +39° 20' | S.S.E. | -4° 99' +52' +39° 23' | +39° 39' | Card steady. | | 21 P.M. | -63° 40' 47" 03' | M. | +40° 22' | S.E.½ S. | -1° 01' +52' +40° 13' | +40° 03' | Card steady. | | | -63° 41' 47" 24' | B. | +42° 45' | S.E. | -1° 37' +52' +40° 00' | +40° 03' | Card steady. | | | -63° 38' 46" 56' | CL. | +41° 11' | S.E. | -1° 37' +52' +40° 26' | +40° 03' | Card steady. | | | -63° 41' 47" 24' | CL. | +41° 50' | S.E. | -1° 37' +52' +41° 05' | +40° 03' | Card steady. | | 22 P.M. | -63° 43' 49" 29' | CL. | +35° 00' | S.S.W.½ W. | -5° 51' +52' +36° 43' | +39° 21' | Very unsteady. | | | -63° 43' 49" 29' | M. | +41° 31' | S.by E. | -2° 51' +52' +39° 04' | +39° 21' | Very unsteady. | | 25 A.M. | -61° 36' 52" 56' | B. | +41° 03' | E.½ N. | -2° 57' +52' +39° 35' | +39° 21' | Very unsteady. | | | -61° 36' 52" 56' | CL. | +41° 40' | E. | -2° 57' +52' +40° 40' | +39° 21' | Very unsteady. | | | -61° 36' 52" 56' | BN. | +42° 45' | E. | -2° 57' +52' +40° 40' | +39° 21' | Very unsteady. | | 25 P.M. | -61° 30' 53" 43' | M. | +40° 31' | S.E.by E. | -1° 13' +52' +42° 53' | +40° 30' | Card steady. | | | -61° 30' 55" 13' | CL. | +43° 14' | S.E.by S. | -1° 56' +52' +41° 26' | +40° 30' | Card steady. | | | -61° 28' 55" 14' | M. | +42° 30' | S.E.½ E. | +0° 03' +52' +43° 39' | +40° 30' | Card steady. | | 26 A.M. | -61° 19' 56" 52' | B. | +42° 44' | S.E.½ E. | -1° 57' +52' +42° 51' | +40° 30' | Card steady. | | | -61° 19' 57" 26' | M. | +43° 56' | S.E.½ E. | -1° 57' +52' +40° 55' | +40° 30' | Card steady. | | | -61° 19' 57" 30' | M. | +42° 00' | S.E.½ E. | -1° 57' +52' +41° 06' | +40° 30' | Card steady. | | 26 P.M. | -61° 17' 58" 30' | CL. | +43° 29' | S.E. | -1° 46' +52' +42° 35' | +40° 30' | Card steady. | | | -61° 17' 58" 30' | M. | +41° 42' | S.E.½ E. | -1° 57' +52' +40° 37' | +40° 30' | Card steady. | | 27 A.M. | -61° 02' 62" 55' | B. | +46° 08' | E. | -3° 21' +52' +43° 39' | +45° 17' | Very unsteady. | | | -61° 02' 62" 55' | BN. | +46° 02' | S.E.½ S. | -1° 40' +52' +45° 14' | +45° 17' | Very unsteady. | | | -61° 02' 64" 10' | M. | +47° 17' | S.E.½ S. | -1° 40' +52' +46° 29' | +45° 17' | Very unsteady. | | 27 P.M. | -61° 10' 65" 00' | CL. | +45° 48' | S.S.E. | -5° 56' +52' +45° 44' | +45° 17' | Steady. | | 28 P.M. | -61° 43' 69" 36' | M. | +46° 00' | S.S.E. | -1° 01' +52' +45° 51' | +45° 51' | Steady. | | March 1 A.M. | -62° 10' 72" 24' | CL. | +46° 09' | S.S.E. | -1° 02' +52' +45° 54' | +45° 51' | Steady. | | 1 P.M. | -62° 10' 72" 25' | M. | +46° 19' | S.E.½ E. | -1° 19' +52' +45° 52' | +45° 51' | Steady. | | | -62° 10' 72" 26' | M. | +47° 55' | S.E.by E. | -1° 19' +52' +45° 40' | +45° 51' | Steady. | | | -62° 10' 72" 26' | CL. | +46° 07' | S.S.E.½ E. | -1° 19' +52' +45° 45' | +45° 51' | Steady. | | | -62° 10' 72" 26' | CL. | +46° 12' | S.S.E.½ E. | -1° 19' +52' +45° 45' | +45° 51' | Steady. | | 2 A.M. | -62° 36' 75" 42' | B. | +50° 57' | S.½ E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 43' 76" 05' | M. | +49° 39' | S.½ E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 43' 76" 05' | CL. | +49° 31' | S.by E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 43' 76" 05' | CL. | +49° 10' | S. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 43' 76" 05' | CM. | +49° 50' | S.by E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | 2 P.M. | -62° 46' 76" 50' | M. | +49° 52' | S.½ E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 46' 76" 50' | T. | +48° 18' | S.½ E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 46' 76" 50' | CL. | +48° 37' | S.½ E. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 54' 76" 59' | B. | +50° 33' | S. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 54' 76" 59' | CL. | +50° 17' | S. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | | | -62° 54' 76" 59' | BN. | +51° 31' | S. | -1° 37' +52' +46° 46' | +45° 51' | Steady. | ## MAGNETIC SURVEY OF A PART OF THE SOUTHERN HEMISPHERE. ### Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|------------------| | **1845,** | | | | | | | | | | | March 4 | | | | | | | | | | | A.M. | | | | | | | | | | | 5 A.M. | -63° | 05' | CL. | +55° 33' | E. ½ N. | -76° 20' | -4° 08' | +52° 17' | +52° 17' | | | -61° | 41' | M. | +50 48 | S.E. ½ S. | -2° 27' | +52° 17' | +49° 13' | | | | -61° | 42' | B. | +49 37 | S.E. | -2° 36' | +52° 17' | +47° 53' | | | | -61° | 41' | CL. | +52 14 | S.E. | -2° 36' | +52° 17' | +50° 30' | | | | -61° | 41' | T. | +49 55 | S.E. | -2° 36' | +52° 17' | +48° 11' | | | | -61° | 41' | CL. | +47 11 | S.E. ½ S. | -2° 27' | +52° 17' | +45° 36' | | | | -61° | 41' | B. | +46 36 | S.E. ½ S. | -2° 27' | +52° 17' | +45° 01' | | | | -61° | 41' | M. | +46 24 | S.E. ½ S. | -2° 27' | +52° 17' | +44° 49' | | | | -60° | 51' | 87° 20' | B. | +52 54 | -3° 38' | +52° 17' | +50° 08' | | | | -60° | 51' | BN. | +49 16 | N.E. | -4° 32' | +52° 17' | +45° 36' | | | | -60° | 48' | 88° 23' | CL. | +49 25 | -2° 40' | +52° 17' | +47° 37' | | | | -61° | 10' | 90° 26' | B. | +50 52 | -1° 20' | +52° 17' | +50° 24' | | | | -61° | 20' | 91° 00' | M. | +50 04 | -3° 30' | +52° 17' | +50° 26' | | | | -61° | 20' | CL. | +47 29 | s. by E. | +3° 34' | +52° 17' | +48° 55' | | | | -61° | 20' | CL. | +46 47 | s. ¼ W. | -2° 20' | +52° 17' | +47° 19' | | | | -61° | 20' | 91° 00' | T. | +48 53 | +1° 15' | +52° 17' | +50° 00' | | | | -61° | 28' | 91° 58' | CL. | +45 22 | +2° 13' | +52° 17' | +49° 28' | Unsteady. | | | -61° | 28' | 91° 58' | CL. | +46 48 | +2° 13' | +52° 17' | +49° 53' | | | | -61° | 28' | 91° 58' | BN. | +46 32 | +2° 00' | +52° 17' | +49° 24' | | | | -61° | 28' | 91° 58' | M. | +46 19 | +1° 38' | +52° 17' | +48° 49' | | | | -61° | 30' | 92° 00' | B. | +48 30 | +1° 38' | +52° 17' | +51° 00' | | | | -61° | 27' | 91° 32' | BN. | +53 20 | -4° 11' | +52° 17' | +50° 01' | Amplitude. | | | -61° | 27' | 91° 32' | B. | +52 57 | -4° 15' | +52° 17' | +49° 34' | | | | -61° | 27' | 91° 32' | BN. | +51 53 | -4° 11' | +52° 17' | +48° 34' | | | | -61° | 15' | 92° 00' | CL. | +53 18 | -4° 20' | +52° 17' | +49° 50' | | | | -61° | 03' | 91° 49' | B. | +52 26 | -4° 46' | +52° 17' | +48° 32' | | | | -61° | 03' | 91° 49' | B. | +51 01 | -4° 34' | +52° 17' | +47° 19' | | | | -61° | 03' | 91° 49' | T. | +52 44 | -4° 23' | +52° 17' | +49° 23' | | | | -60° | 58' | 92° 02' | B. | +48 53 | -4° 34' | +52° 17' | +45° 11' | | | | -60° | 58' | 92° 02' | BN. | +52 21 | -4° 10' | +52° 17' | +49° 03' | | | | -60° | 58' | 92° 04' | BN. | +52 42 | -4° 34' | +52° 17' | +49° 00' | | | | -60° | 50' | 92° 10' | B. | +52 59 | -4° 46' | +52° 17' | +49° 17' | | | | -60° | 30' | 92° 27' | M. | +51 50 | -4° 11' | +52° 17' | +47° 56' | | | | -60° | 22' | 93° 17' | B. | +51 00 | -4° 20' | +52° 17' | +44° 41' | | | | -60° | 03' | 94° 00' | BN. | +48 09 | -4° 23' | +52° 17' | +42° 40' | | | | -60° | 03' | 94° 01' | B. | +46 11 | -2° 49' | +52° 17' | +46° 13' | | | | -60° | 03' | 96° 30' | M. | +48 10 | -2° 49' | +52° 17' | +45° 57' | | | | -60° | 03' | 96° 30' | CL. | +47 54 | -2° 26' | +52° 17' | +37° 08' | | | | -60° | 01' | 99° 10' | B. | +38 42 | -4° 54' | +52° 17' | +40° 44' | | | | -59° | 31' | 100° 45' | CL. | +44 46 | -1° 46' | +52° 17' | +43° 26' | | | | -59° | 31' | 100° 45' | M. | +43 03 | -1° 46' | +52° 17' | +42° 09' | | | | -59° | 31' | 100° 45' | CL. | +44 20 | -1° 46' | +52° 17' | +40° 08' | | | | -59° | 31' | 100° 45' | T. | +41 02 | -1° 46' | +52° 17' | +39° 33' | | | | -59° | 31' | 100° 45' | B. | +40 27 | -2° 38' | +52° 17' | +44° 09' | | | | -59° | 31' | 100° 45' | CL. | +45 55 | -3° 33' | +52° 17' | +39° 50' | | | | -58° | 31' | 98° 59' | CL. | +42 31 | -4° 58' | +52° 17' | +42° 50' | | | | -58° | 30' | 98° 32' | CL. | +42 58 | -4° 33' | +52° 17' | +40° 10' | | | | -58° | 30' | 98° 32' | CL. | +43 51 | -4° 02' | +52° 17' | +37° 38' | | | | -56° | 56' | 101° 20' | M. | +40 48 | -4° 02' | +52° 17' | +37° 37' | | | | -55° | 50' | 103° 08' | CL. | +36 52 | -5° 01' | +52° 17' | +32° 43' | | | | -55° | 40' | 103° 18' | M. | +35 37 | -4° 33' | +52° 17' | +31° 56' | | | | -55° | 35' | 103° 20' | CL. | +37 56 | -4° 46' | +52° 17' | +34° 02' | | **3 c 2** ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|----------|----------|----------|----------------------|-------------|-------------|-------------|-----------------------|----------------| | **1845** | | | | | | | | | | | Mar. 16 A.M. | -59° 15'10" 03' | B. | +30° 31' | N.E. | -3° 47' +52' | +27° 36' | | | | | | -54° 42'10" 08' | CL. | +32° 16' | N.E. ½ E. | -3° 56' +52' | +29° 12' | | | | | | -54° 42'10" 08' | T. | +32° 06' | N.E. ½ E. | -3° 56' +52' | +29° 02' | | | | | | -54° 38'10" 28' | M. | +33° 16' | E. | -4° 46' +52' | +29° 22' | | | | | | -54° 38'10" 28' | CL. | +34° 13' | E. | -4° 46' +52' | +30° 19' | | | | | | -54° 36'10" 28' | BN. | +34° 45' | E. | -4° 46' +52' | +30° 51' | | | | | 17 A.M. | -54° 05'10" 15' | CL. | +29° 19' | E. by S. | -4° 52' +52' | +25° 19' | | | | | | -54° 05'10" 15' | M. | +32° 02' | E. ½ S. | -5° 05' +52' | +27° 49' | | | | | 18 A.M. | -53° 30'10" 13' | BN. | +25° 18' | N.N.E. | -2° 37' +52' | +23° 33' | | | | | | -53° 14'10" 24' | M. | +22° 05' | N.E. ½ E. | -2° 58' +52' | +19° 59' | | | | | | -53° 10'10" 27' | M. | +26° 50' | N.E. ½ E. | -4° 01' +52' | +23° 41' | | | | | | -53° 08'10" 29' | M. | +26° 25' | N.E. ½ E. | -3° 47' +52' | +23° 30' | | | | | | -53° 08'10" 29' | CL. | +23° 34' | N.E. ½ E. | -4° 01' +52' | +20° 25' | | | | | 18 P.M. | -53° 03'10" 20' | T. | +20° 00' | N.E. | -48° +52' | +20° 04' | | | | | | -52° 38'10" 30' | CL. | +18° 23' | N.N.E. | -2° 32' +52' | +16° 43' | | | | | 20 A.M. | -49° 22'12" 34' | BN. | +23° 05' | N.E. by N. | -2° 49' +52' | +21° 08' | | | | | | -49° 22'12" 34' | BN. | +21° 06' | N.by E. ½ E. | -2° 04' +52' | +19° 54' | | | | | | -49° 22'12" 34' | BN. | +20° 05' | N.N.E. | -2° 19' +52' | +18° 38' | | | | | | -49° 01'12" 50' | M. | +19° 26' | N.E. | -3° 25' +52' | +16° 53' | | | | | 20 P.M. | -49° 00'12" 51' | CL. | +17° 58' | N.E. ½ N. | -3° 10' +52' | +15° 40' | | | | | | -49° 00'12" 51' | CL. | +18° 30' | N.E. ½ N. | -3° 10' +52' | +16° 12' | | | | | | -48° 59'12" 53' | T. | +21° 50' | N.E. ½ E. | -3° 35' +52' | +19° 07' | | | | | | -48° 54'12" 55' | T. | +17° 12' | N.E. ½ E. | -3° 35' +52' | +14° 29' | | | | | | -48° 56'12" 56' | M. | +17° 24' | N.E. ½ E. | -3° 35' +52' | +14° 41' | | | | | | -48° 56'12" 56' | M. | +17° 33' | N.E. ½ E. | -3° 35' +52' | +14° 50' | | | | | 23 P.M. | -46° 32'11" 54' | M. | +11° 55' | N. ½ W. | -7° 43' +52' | +12° 02' | | | | | | -45° 04'11" 52' | T. | +8° 52' | N. ½ W. | -4° 55' +52' | +8° 59' | | | | | 24 P.M. | -44° 54'11" 55' | M. | +10° 38' | N.by W. ½ W. | -1° 03' +52' | +10° 27' | | | | | | -43° 53'11" 52' | M. | +7° 12' | N.by W. | -3° 00' +52' | +7° 34' | | | | | | -43° 52'11" 59' | B. | +5° 40' | N. ½ W. | -4° 25' +52' | +5° 50' | | | | | | -43° 52'11" 59' | BN. | +8° 18' | N. ½ W. | -5° 45' +52' | +8° 16' | | | | | | -43° 42'11" 59' | CL. | +7° 42' | N. | -1° 00' +52' | +7° 34' | | | | | | -43° 42'11" 59' | T. | +5° 59' | N. | -1° 00' +52' | +5° 51' | | | | | 25 P.M. | -43° 08'11" 55' | CL. | +7° 45' | N. ½ E. | -1° 12' +52' | +7° 25' | | | | | | -41° 29'11" 42' | M. | +3° 45' | N.by W. | -3° 33' +52' | +4° 04' | | | | | 26 A.M. | -40° 54'11" 42' | CL. | +4° 48' | N.by W. | -3° 33' +52' | +5° 07' | | | | | | -40° 42'11" 42' | M. | +3° 10' | N.by W. | -3° 33' +52' | +3° 29' | | | | | 27 A.M. | -39° 00'11" 15' | M. | +7° 09' | N.by W. | -3° 33' +52' | +7° 28' | | | | | | -39° 00'11" 15' | CL. | +6° 26' | N.by W. | -3° 33' +52' | +6° 45' | | | | | 27 P.M. | -38° 32'11" 17' | M. | +7° 48' | N.by E. | -1° 20' +52' | +7° 20' | | | | | | -38° 08'11" 19' | M. | +6° 37' | N.by E. | -1° 20' +52' | +6° 09' | | | | | 28 P.M. | -37° 02'11" 38' | M. | +4° 10' | N.by E. ½ E. | -1° 11' +52' | +3° 51' | | | | | | -36° 46'11" 35' | M. | +5° 45' | N.N.E. | -1° 26' +52' | +5° 11' | | | | | | -36° 46'11" 35' | CL. | +5° 13' | N.N.E. ½ E. | -1° 33' +52' | +4° 32' | | | | | 29 A.M. | -36° 13'11" 40' | M. | +4° 49' | N.by E. | -1° 07' +52' | +4° 34' | | | | | | -36° 12'11" 40' | M. | +5° 56' | N.by E. | -1° 07' +52' | +5° 41' | | | | | | -36° 13'11" 40' | CL. | +4° 29' | N.by E. | -1° 07' +52' | +4° 14' | | | | | | -36° 12'11" 40' | T. | +4° 52' | N.by E. | -1° 07' +52' | +4° 37' | | | | | | -36° 11'11" 40' | M. | +5° 38' | N. | -1° 07' +52' | +5° 37' | | | | | 29 P.M. | -36° 10'11" 47' | BN. | +4° 37' | N.E. ½ E. | -1° 56' +52' | +3° 33' | | | | | | -36° 10'11" 47' | CL. | +6° 01' | N.E. ½ E. | -1° 56' +52' | +4° 57' | | | | | | -36° 08'11" 54' | M. | +6° 48' | N.E. ½ E. | -1° 56' +52' | +5° 44' | | | | | 30 A.M. | -35° 09'11" 41' | CL. | +7° 10' | S.E. ½ E. | -1° 34' +52' | +6° 28' | | | | | | -35° 09'11" 41' | CL. | +6° 54' | S. ½ E. | -1° 59' +52' | +6° 47' | | | | | | -35° 14'11" 41' | CL. | +4° 52' | S. ½ E. | -1° 13' +52' | +5° 44' | | | | | | -35° 14'11" 41' | BN. | +5° 05' | S. ½ E. | -1° 03' +52' | +7° 12' | | | | | | -35° 14'11" 41' | M. | +6° 23' | S. | -1° 03' +52' | +6° 20' | | | | ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head. | Inclination. | Corrections. | Corrected Declination. | Remarks | |------------|----------|---------|----------|----------------------|--------------|-------------|---------------|------------------------|-----------------| | **1845.** | | | | | | | | | | | Mar. 31 A.M. | -35° 28' 11" 04' | CL. | +7° 59' | N.E. ½ E. | -65° 20' | -1° 56' | +5° 52' | +6° 55' | +6° 55' | Unsteady. | | April 1 A.M. | -35° 08' 11" 50' | CL. | +9° 57' | N.N.E. | -65° 00' | -1° 22' | +5° 52' | +9° 27' | +9° 27' | Unsteady. | | 11 A.M. | -35° 02' 11" 56' | M. | +4° 17' | Observed on shore. | +5° 52' | +5° 09' | +5° 52' | +5° 52' | Card J. | | 14 A.M. | King George's Sound, Australia | CL. | +4° 53' | | | | | | Card J. | | 21 A.M. | -35° 10' 11" 06' | M. | +3° 48' | W. by S. | -65° 11' | +1° 17' | +5° 52' | +5° 57' | +5° 57' | Card J. unsteady. | | 22 A.M. | -35° 42' 11" 40' | M. | +5° 10' | S. | -65° 11' | +0° 31' | +5° 52' | +5° 59' | +5° 59' | Unsteady. | | 23 A.M. | -35° 40' 11" 55' | CL. | +3° 05' | N.W. | | | | | Card A. | | | -35° 38' 11" 50' | M. | +4° 33' | N.N.W. ½ W. | -65° 11' | +0° 59' | +5° 52' | +5° 59' | +5° 41' | Unsteady. | | 23 P.M. | -35° 23' 11" 21' | M. | +6° 29' | N.W. by N. | | | | | Card unsteady. | | 24 A.M. | -34° 24' 11" 17' | M. | +6° 31' | N.W. by N. | | | | | Card unsteady. | | | -34° 20' 11" 15' | CL. | +6° 10' | N.W. by N. | -64° 44' | | | | Card unsteady. | | | -34° 17' 11" 12' | CL. | +5° 34' | N.W. by N. | | | | | Card unsteady. | | Noon. | -34° 12' 11" 05' | M. | +5° 00' | N.W. by N. | | | | | Card unsteady. | | 25 A.M. | -32° 48' 11" 44' | M. | +6° 55' | N.W. by N. | | | | | Steady. | | | -32° 48' 11" 45' | CM. | +6° 04' | N.W. by N. | -62° 18' | | | | Steady. | | | -32° 40' 11" 44' | CL. | +5° 20' | N.W. ½ N. | | | | | Steady. | | | -32° 38' 11" 43' | CL. | +5° 05' | N.W. ½ N. | | | | | Steady. | | | -32° 35' 11" 40' | CL. | +5° 53' | N.W. by N. | | | | | Steady. | | 26 A.M. | -30° 31' 10" 15' | CL. | +5° 58' | N.W. by N. | | | | | Steady. | | | -30° 31' 10" 15' | BN. | +6° 25' | N.W. by N. | -60° 30' | | | | Steady. | | 26 P.M. | -30° 26' 10" 58' | M. | +5° 58' | N.W. | | | | | Steady. | | | -30° 15' 10" 58' | CL. | +7° 52' | N.W. | | | | | Steady. | | 27 A.M. | -29° 20' 10" 55' | M. | +6° 04' | N.W. ½ W. | -59° 25' | | | | Steady. | | | -29° 20' 10" 55' | M. | +5° 00' | N.W. | | | | | Steady. | | 28 A.M. | -27° 57' 10" 36' | M. | +8° 27' | N. | -57° 22' | | | | Very unsteady. | | 28 P.M. | -27° 25' 10" 34' | CL. | +4° 26' | N. by W. | | | | | Very unsteady. | | 29 A.M. | -26° 10' 10" 16' | M. | +3° 56' | N.W. | | | | | Very unsteady. | | | -26° 10' 10" 16' | CL. | +5° 52' | N.W. | -55° 07' | | | | Very unsteady. | | | -26° 10' 10" 16' | BN. | +5° 28' | N.W. | | | | | Very unsteady. | | 30 A.M. | -24° 10' 10" 30' | CL. | +3° 58' | W.N.W. | -54° 30' | | | | Very unsteady. | | | -24° 05' 10" 26' | CL. | +4° 42' | W.N.W. | | | | | Very unsteady. | | May 1 A.M. | -23° 58' 99" 26' | CL. | +3° 02' | W. | | | | | Compass steady. | | | -23° 58' 99" 25' | CL. | +3° 00' | W. | -54° 07' | | | | Compass steady. | | | -23° 58' 99" 22' | M. | +4° 25' | W. | | | | | Compass steady. | | Noon. | -23° 58' 99" 13' | M. | +4° 30' | W. | | | | | Compass steady. | | 2 A.M. | -24° 01' 97" 34' | M. | +7° 57' | N.by E. ½ E. | | | | | Compass steady. | | | -24° 01' 97" 34' | BN. | +6° 26' | N.by E. ½ E. | -54° 11' | | | | Compass steady. | | | -24° 01' 97" 34' | CL. | +6° 47' | N.N.E. | | | | | Compass steady. | | 3 A.M. | -23° 55' 95" 58' | M. | +5° 58' | W. ½ N. | | | | | Steady. | | | -23° 55' 95" 58' | M. | +4° 58' | W. ½ N. | | | | | Steady. | | | -23° 55' 95" 58' | CL. | +3° 40' | W. ½ N. | | | | | Steady. | | 3 P.M. | -24° 00' 95" 25' | M. | +4° 41' | W. ½ S. | | | | | Steady. | | | -24° 00' 95" 25' | CL. | +4° 05' | W. ½ S. | | | | | Steady. | | | -23° 55' 95" 50' | CM. | +4° 42' | W. ½ S. | | | | | Steady. | | 4 A.M. | -24° 17' 94" 08' | CL. | +5° 09' | W.N.W. | | | | | Steady. | | | -24° 17' 94" 10' | M. | +4° 22' | W.N.W. | -54° 07' | | | | Steady. | | | -24° 17' 94" 10' | M. | +3° 51' | W.N.W. | | | | | Steady. | | Noon. | -24° 17' 93" 58' | M. | +4° 30' | W.N.W. | | | | | Steady. | | 5 A.M. | -24° 05' 92" 11' | CL. | +6° 05' | N.W. by N. | | | | | Steady. | | 6 A.M. | -22° 54' 90" 50' | M. | +4° 38' | N.W. | | | | | Steady. | | | -22° 54' 90" 50' | BN. | +4° 57' | N.W. | | | | | Steady. | | | -22° 54' 90" 50' | CL. | +4° 49' | N.W. | | | | | Steady. | | | -22° 50' 90" 48' | CL. | +5° 04' | N.W. | | | | | Steady. | | 6 P.M. | -22° 39' 90" 35' | M. | +5° 59' | N.W. by N. | -52° 49' | | | | Compass steady. | ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|-------------------------| | **1845.** | | | | | | | | | | | May 6 P.M.| -22°39' | 90°32' | M. | +6°12' | N.N.W. | -52°49' | ° 34' +5°2' | +6°30' +5°56' | Compass steady. | | | -22°39' | 90°32' | Bn. | +4°40' | N.W. by N. | -23°+5°2' | +5°09' | | | | | -22°39' | 90°32' | Cl. | +5°53' | N.W. by N. | -23°+5°2' | +6°22' | | | | Sunset. | -22°39' | 90°32' | Cl. | +6°33' | N.W.W. | -34°+5°2' | +6°51' | | | | 7 A.M. | -21°53' | 89°42' | M. | +3°30' | N.W. | -18°+5°2' | +4°04' | +4°23' | Unsteady. | | | -21°53' | 89°42' | Cl. | +4°09' | N.W. | -18°+5°2' | +4°43' | | | | | -20°48' | 88°08' | M. | +3°42' | N.W.by W. | -10°+5°2' | +4°24' | | | | | -20°47' | 88°05' | M. | +3°53' | N.W.by W. | -10°+5°2' | +4°35' | | | | | -20°45' | 88°05' | Cl. | +3°25' | N.W.by W. | -51°15' | +10°+5°2' | +4°07' +4°45' | Card steady. | | | -20°45' | 88°05' | Bn. | +4°11' | N.W.by W. | -51°15' | +10°+5°2' | +4°43' | | | Noon. | -20°38' | 87°56' | M. | +4°30' | W.½ N. | +26°+5°2' | +5°48' | | | | 9 A.M. | -20°37' | 85°39' | M. | +4°38' | W.½ N. | +26°+5°2' | +5°48' | | | | | -20°37' | 85°39' | Cl. | +3°28' | W.½ N. | +26°+5°2' | +5°48' | | | | Noon. | -20°37' | 85°19' | M. | +4°00' | W.½ N. | +26°+5°2' | +5°48' | | | | 10 A.M. | -20°25' | 82°45' | M. | +4°12' | W.½ N. | +26°+5°2' | +5°48' | | | | | -20°25' | 82°24' | M. | +4°17' | W.½ N. | +26°+5°2' | +5°48' | | | | | -20°25' | 82°30' | Bn. | +3°06' | W.½ N. | +26°+5°2' | +5°48' | | | | | -20°25' | 82°30' | Cl. | +3°26' | W.½ N. | +26°+5°2' | +5°48' | | | | | -20°25' | 82°30' | T. | +4°08' | W.½ N. | +26°+5°2' | +5°48' | | | | 11 A.M. | -20°36' | 79°36' | M. | +2°56' | W.½ N. | +24°+5°2' | +4°12' | | | | | -20°36' | 79°34' | M. | +2°31' | W.½ N. | +24°+5°2' | +3°47' | | | | | -20°36' | 79°34' | Bn. | +2°27' | W.½ N. | +24°+5°2' | +3°43' | | | | | -20°36' | 79°34' | Cl. | +3°12' | W.½ N. | +24°+5°2' | +3°43' | | | | 11 P.M. | -20°36' | 79°00' | M. | +4°48' | W.½ N. | +24°+5°2' | +4°28' | +4°43' | Compass unsteady. | | | -20°36' | 79°00' | Cl. | +4°34' | W.½ N. | +24°+5°2' | +6°04' | | | | | -20°36' | 79°00' | T. | +3°43' | W.½ N. | +24°+5°2' | +5°50' | | | | 12 A.M. | -20°44' | 78°34' | M. | +5°38' | N. | -50°+5°2' | +5°40' | | | | | -20°44' | 78°34' | Cl. | +6°28' | N. | -50°+5°2' | +6°30' | | | | | -20°44' | 78°34' | M. | +5°06' | N.N.W. | -38°+5°2' | +5°20' | | | | | -20°44' | 78°34' | Cl. | +6°32' | N.N.W. | -38°+5°2' | +6°46' | | | | | -20°44' | 78°34' | M. | +5°27' | N.W. | -22°+5°2' | +5°57' | | | | | -20°44' | 78°34' | Cl. | +5°12' | N.W. | -22°+5°2' | +5°42' | | | | | -20°44' | 78°34' | M. | +3°23' | W.N.W. | +04°+5°2' | +4°19' | | | | | -20°44' | 78°34' | Cl. | +5°36' | W.N.W. | +04°+5°2' | +6°32' | | | | | -20°44' | 78°34' | M. | +2°23' | W. | +20°+5°2' | +3°35' | | | | | -20°44' | 78°34' | Cl. | +4°09' | W. | +20°+5°2' | +5°21' | | | | | -20°44' | 78°34' | M. | +2°58' | W.S.W. | +15°+5°2' | +4°05' | +5°29' | To obtain corrections for the ship's attraction. A calm, heavy swell, compass unsteady. | | | -20°44' | 78°34' | Cl. | +4°22' | W.S.W. | +15°+5°2' | +5°29' | | | | | -20°44' | 78°34' | M. | +4°20' | S.W. | +06°+5°2' | +5°18' | | | | | -20°44' | 78°34' | Cl. | +4°26' | S.W. | +06°+5°2' | +5°24' | | | | | -20°44' | 78°34' | M. | +4°46' | S.S.W. | +01°+5°2' | +5°37' | | | | | -20°44' | 78°34' | Cl. | +4°48' | S.S.W. | +01°+5°2' | +5°39' | | | | | -20°44' | 78°34' | M. | +4°42' | S. | +08°+5°2' | +5°26' | | | | | -20°44' | 78°34' | Cl. | +4°29' | S. | +08°+5°2' | +5°13' | | | | | -20°44' | 78°34' | M. | +5°41' | E.N.E. | -1°13°+5°2' | +5°20' | | | | | -20°44' | 78°34' | Cl. | +6°00' | E.N.E. | -1°13°+5°2' | +5°39' | | | | | -20°44' | 78°34' | M. | +6°21' | N.N.E. | -57°+5°2' | +6°16' | | | | 13 A.M. | -20°39' | 77°45' | Cl. | +4°11' | W. | +20°+5°2' | +5°23' | | | | | -20°39' | 77°45' | T. | +4°29' | W. | +20°+5°2' | +5°41' | +5°22' | Steady. | | | -20°39' | 77°45' | M. | +3°49' | W. | +20°+5°2' | +5°01' | | | | 14 A.M. | -20°28' | 76°23' | M. | +4°43' | W.½ N. | +16°+5°2' | +5°51' | | | | | -20°28' | 76°23' | Bn. | +4°25' | W.½ N. | +16°+5°2' | +5°51' | | | | | -20°28' | 76°23' | Cl. | +5°31' | W.½ N. | +16°+5°2' | +6°39' | | | | 15 A.M. | -20°45' | 73°20' | M. | +4°46' | W.½ N. | +16°+5°2' | +5°54' | +5°54' | Unsteady. | | 16 A.M. | -20°27' | 70°49' | M. | +6°12' | W.½ N. | +16°+5°2' | +7°20' | +6°35' | Card unsteady. | | | -20°27' | 70°49' | Cl. | +4°43' | W.½ N. | +16°+5°2' | +5°51' | | | ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|---------| | **May 17 A.M.** | | | | | | | | | | | -20°34'69" | CL | +5°06' | w. | -53°01' | +20°+52°+6°18' | +6°07' | Card unsteady. | | -20°34'69" | CL | +4°45' | w. | | +20°+52°+5°57' | | | | -21°06'68" | CL | +6°28' | w.½ s. | | +20°+52°+7°40' | | | | -21°00'68" | M | +6°24' | w. by s. | | +18°+52°+7°34' | | | | -20°52'68" | M | +7°35' | N.N.W. | | -37°+52°+7°50' | +8°00' | Compass steady. | | -20°52'68" | BN | +8°59' | N.N.W. | | -37°+52°+9°14' | | | | Sunset | | | | | -47°+52°+7°40' | | | | -21°00'68" | M | +7°45' | N.by W.½ W.| | -19°+52°+7°13' | | | | -21°11'67" | CL | +6°40' | N.W.½ N. | | -23°+52°+6°50' | +6°34' | Card steady. | | -21°11'67" | T | +5°11' | N.W.½ N. | | -23°+52°+5°40' | | | | -21°12'67" | CL | +6°24' | w. by N. | | +15°+52°+7°31' | +7°37' | Steady. | | -21°12'67" | BN | +6°36' | w. by N. | | +15°+52°+7°43' | | | | -21°01'66" | CL | +6°53' | w. by N. | | +15°+52°+8°00' | | | | -21°01'66" | BN | +6°34' | w. by N. | | +15°+52°+7°41' | +7°46' | | | -21°01'66" | M | +6°30' | w. by N. | | +15°+52°+7°37' | | | | -20°41'63" | M | +7°17' | w. by N. | | +15°+52°+8°24' | | | | -20°38'62" | M | +7°23' | w. by N. | | +15°+52°+8°30' | +8°27' | | | -20°30'59" | CL | +8°40' | w. by N. | | +15°+52°+9°47' | | | | -20°30'59" | BN | +8°12' | w. by N. | | +15°+52°+9°19' | +9°44' | | | -20°30'59" | M | +9°00' | w. by N. | | +15°+52°+10°07' | | | | -19°54'57" | M | +8°15' | w.½ N. | | +20°+52°+9°27' | +9°27' | Very unsteady. | | -20°09'57" | M | +8°31' | On shore. | | +52°+9°23' | +9°44' | Port Louis, Mauritius. | | -20°50'55" | CL | +9°13' | w. | | +52°+10°05' | | | | -20°50'55" | M | +10°47' | w.½ N. | | +26°+52°+10°31' | +11°15' | Card steady. | | -21°30'53" | M | +12°09' | s.w.byw.½ W.| | +20°+52°+11°59' | | | | -22°02'52" | CL | +12°44' | s.w.by w. | | +19°+52°+13°20' | | | | -22°02'52" | B | +12°34' | s.w.by w. | | +16°+52°+13°52' | +13°44' | | | -22°02'52" | M | +12°54' | s.w.by w. | | +16°+52°+13°42' | | | | -23°44'51" | CL | +12°17' | s.w.byw.½ W.| | +16°+52°+14°02' | | | | -23°44'51" | M | +13°28' | s.w.byw.½ W.| | +19°+52°+13°28' | | | | June 1 A.M. | | | | | +19°+52°+14°59' | +14°22' | Card unsteady. | | -25°47'49" | CL | +14°16' | W.S.W. | | +19°+52°+14°39' | | | | -25°47'49" | M | +13°24' | W.S.W. | | +27°+52°+15°35' | +15°09' | Unsteady. | | -26°30'49" | M | +15°38' | N.W. | | +27°+52°+14°43' | | | | -26°30'49" | CL | +15°25' | N.W. | | +01°+52°+16°29' | | | | -26°30'49" | T | +15°32' | N.W. | | +01°+52°+16°16' | +16°23' | | | -27°10'46" | CL | +19°50' | w.by s. | | +01°+52°+16°23' | | | | -27°10'46" | M | +19°01' | w.by s. | | +48°+52°+21°30' | | | | -27°07'46" | M | +17°56' | w.by s. | | +48°+52°+20°41' | | | | -27°14'45" | M | +19°18' | w.by s. | | +48°+52°+19°36' | +20°25' | Very unsteady. | | Sunset | | | | | +48°+52°+20°58' | | | | -27°18'45" | CL | +17°38' | w. | | +51°+52°+19°21' | | | | -28°19'43" | CL | +19°40' | w. | | +31°+52°+21°03' | | | | -28°19'43" | M | +21°14' | w. | | +31°+52°+22°37' | +21°19' | Card very unsteady. | | -28°20'43" | CL | +18°55' | w. | | +31°+52°+20°18' | | | | -28°50'42" | M | +19°58' | N.W.by w. | | +12°+52°+21°02' | | | | -28°49'42" | CL | +19°47' | N.W.by w. | | +12°+52°+20°58' | | | | -28°49'42" | CL | +21°48' | N.W.by w. | | +12°+52°+20°51' | | | | -28°46'42" | M | +22°00' | N.W.by w. | | +12°+52°+22°52' | | | | 7 A.M. | | | | | +12°+52°+22°34' | | | | -28°32'40" | M | +21°48' | w.by N. | | +22°+52°+23°02' | | | | -28°38'40" | CL | +21°29' | w.by N. | | +22°+52°+22°43' | | | | -28°32'40" | CL | +21°04' | w.by N. | | +22°+52°+22°18' | +22°34' | Unsteady. | | -28°40'39" | M | +21°17' | w.by N. | | +22°+52°+22°31' | | | | -28°40'39" | CL | +21°04' | w.by N. | | +22°+52°+22°18' | | | ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|---------| | **1845.** | | | | | | | | | | | June 8 A.M.| -28° | 50' | M. | +21° 41' | w. | | | | | | | -28° | 53' | M. | +22° 17' | w. | | | | | | | -28° | 56' | CL. | +21° 49' | w. | | | | | | | -28° | 56' | T. | +22° 00' | w. | | | | | | | -28° | 58' | M. | +21° 44' | w. | | | | | | 8 P.M. | -29° | 03' | M. | +23° 19' | w. | | | | | | Sunset. | -29° | 03' | CL. | +22° 48' | w. | | | | | | 9 A.M. | -30° | 20' | M. | +25° 36' | w. | | | | | | | -30° | 16' | CL. | +24° 38' | w. | | | | | | 11 A.M. | -30° | 30' | M. | +26° 28' | N.W. by w. | | | | | | 11 P.M. | -30° | 27' | CL. | +24° 42' | w. | | | | | | | -30° | 30' | M. | +27° 05' | S.E. | | | | | | | -30° | 30' | M. | +26° 59' | N.E. | | | | | | | -30° | 33' | BN. | +27° 43' | S.E. | | | | | | | -30° | 33' | CL. | +29° 36' | S.E. | | | | | | 12 A.M. | -30° | 35' | M. | +23° 58' | W. by N. | | | | | | 13 A.M. | -31° | 05' | M. | +25° 15' | W. by s. | | | | | | | -31° | 05' | M. | +25° 22' | W. by s. | | | | | | | -31° | 06' | M. | +25° 13' | W. by s. | | | | | | | -31° | 10' | M. | +25° 25' | W. by s. | | | | | | | -31° | 05' | BN. | +27° 16' | W. by s. | | | | | | | -31° | 05' | CL. | +25° 46' | W. by s. | | | | | | 13 P.M. | -31° | 12' | CL. | +24° 39' | S.W.byw. | | | | | | | -31° | 18' | M. | +25° 06' | S.W.byw. | | | | | | | -31° | 18' | CL. | +25° 26' | S.W.byw. | | | | | | 14 A.M. | -32° | 50' | M. | +28° 06' | S.W.byw. | | | | | | | -32° | 53' | CL. | +27° 02' | W. | | | | | | | -32° | 53' | CL. | +27° 19' | W. | | | | | | | -33° | 00' | CL. | +27° 09' | W. | | | | | | 15 A.M. | -34° | 36' | M. | +27° 06' | W. | | | | | | | -34° | 36' | T. | +26° 23' | W. | | | | | | | -34° | 45' | M. | +26° 08' | W. | | | | | | | -34° | 40' | CL. | +27° 58' | W. | | | | | | | -34° | 40' | BN. | +28° 21' | W. | | | | | | | -34° | 45' | CL. | +26° 52' | W. | | | | | | 15 Noon. | -34° | 51' | M. | +28° 50' | N.W.byw. | | | | | | P.M. | -34° | 51' | M. | +27° 54' | N.W.byw. | | | | | | | -34° | 51' | CL. | +27° 54' | N.W.byw. | | | | | | 16 A.M. | -35° | 36' | M. | +27° 11' | W. | | | | | | | -35° | 36' | CL. | +27° 26' | W. | | | | | | | -35° | 40' | CL. | +28° 06' | W. | | | | | | | -35° | 42' | CL. | +28° 14' | W. | | | | | | | -35° | 43' | CL. | +31° 16' | N. | | | | | | 17 A.M. | -35° | 40' | CL. | +28° 38' | N.W. | | | | | | | -35° | 40' | M. | +28° 21' | N.W.W. | | | | | | 18 A.M. | -35° | 06' | M. | +26° 41' | W. | | | | | | 19 A.M. | -35° | 08' | CL. | +27° 29' | S.W. | | | | | | | -35° | 08' | M. | +27° 43' | S.W. | | | | | | 20 A.M. | -34° | 55' | CL. | +29° 00' | N.W. | | | | | | | -34° | 55' | CL. | +28° 14' | N.W.byw. | | | | | | | -34° | 55' | CL. | +27° 34' | N.W. | | | | | ### Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Corrections | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|-------------|----------------------|---------| | **1845.** | | | | | | | | | | | June 23. | -34° | 12' | M. | +29° 11' | N. | | | | | | | | | M. | +28° 52' | N.N.W. | | | | | | | | | M. | +28° 23' | N.W. | | | | | | | | | M. | +28° 23' | W.N.W. | | | | | | | | | M. | +27° 40' | W. | | | | | | | | | M. | +27° 28' | W.S.W. | | | | | | | | | M. | +27° 14' | S.W. | | | | | | | | | M. | +27° 40' | S.S.W. | | | | | | | | | M. | +28° 36' | S. | | | | | | | | | M. | +29° 30' | S.S.E. | | | | | | | | | M. | +29° 34' | S.E. | | | | | | | | | M. | +29° 47' | E.S.E. | | | | | | | | | M. | +30° 22' | E. | | | | | | | | | M. | +29° 56' | E.N.E. | | | | | | | | | M. | +29° 51' | N.E. | | | | | | | | | M. | +29° 26' | N.N.E. | | | | | | July 1. | -33° | 56' | Cl. | +28° 26' | | | | | | | Magnetic Observatory, Cape of Good Hope. | | | | | | | | | | | | | | Cl. | +28° 11' | | | | | | | | | | Cl. | +28° 07' | | | | | | | | | | Cl. | +28° 20' | | | | | | To obtain the Index Corrections for Cards A and J; true Declination = +29° 07'. Card J. error -52'. Card A. error -47'. Observations of the Inclination made on board Her Majesty's hired Bark "Pagoda," from the 10th of January to the 21st of July 1845, with Needle A (Fox C. 9). Face East. Observer Lieut. T. E. L. Moore, R.N. One hour after Noon. | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections. | Corrected Inclination. | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|--------------|------------------------|--------------------------| | | | | | | | | | | | 1845. | | | | | | | | | | Jan. 10. | -34° 46' | 17° 46' | Direct. | -54° 26' | W. by N. | | | | | | | | Needle N. | -54° 44' | W. by N. | | | | | | | | Needle S. | -53° 27' | W. by N. | | | | | | | | Mag. N. | -54° 22' | W. by N. | | | | | | | | Mag. N.S. | -53° 53' | W. by N. | | | | | | | | Mag. S. | -53° 54' | W. by N. | | | | | | | | Direct. | -54° 32' | W. by N. | | | | | | | | Needle N. | -52° 27' | N.W. by W. | | | Fresh breeze, a head swell. | | | | | Needle S. | -52° 38' | N.W. by W. | | | | | | | | Mag. N.S. | -51° 42' | N.W. by W. | | | | | | | | Mag. N. | -52° 55' | N.W. by W. | | | | | | | | Mag. S. | -52° 15' | N.W. by W. | | | | | | | | Direct. | -52° 09' | N.W. by W. | | | | | | | | Needle N. | -51° 45' | W. ½ S. | | | | | | | | Needle S. | -52° 17' | W. ½ S. | | | | | | | | Mag. N.S. | -51° 20' | W. ½ S. | | | | | | | | Mag. N. | -51° 56' | W. ½ S. | | | | | | | | Mag. S. | -51° 29' | W. ½ S. | | | | | | | | Direct. | -51° 26' | W. ½ S. | | | | | | | | Needle N. | -51° 31' | W. ½ S. | | | | | | | | Needle S. | -51° 38' | S.W. ½ S. | | | | | | | | Mag. N.S. | -51° 31' | S.W. ½ S. | | | | | | | | Mag. N. | -50° 41' | S.W. ½ S. | | | | | | | | Mag. S. | -51° 42' | S.W. ½ S. | | | | | | | | Direct. | -51° 18' | S.W. ½ S. | | | | | | | | Needle N. | -51° 10' | S.W. ½ S. | | | | | | | | Needle S. | -53° 30' | S. by W. ½ W.| | | | | | | | Mag. N.S. | -53° 47' | S. by W. ½ W.| | | | | | | | Mag. N. | -52° 36' | S. by W. ½ W.| | | | | | | | Mag. S. | -53° 38' | S. by W. ½ W.| | | | | | | | Direct. | -53° 19' | S. by W. ½ W.| | | | | | | | Needle N. | -53° 22' | S. by W. ½ W.| | | | | | | | Needle S. | -53° 33' | S. by W. ½ W.| | | | | | | | Mag. N.S. | -54° 03' | S.W.byW.½W.| | | | | | | | Mag. N. | -54° 24' | S.W.byW.½W.| | | | | | | | Mag. S. | -53° 30' | S.W.byW.½W.| | | | | | | | Direct. | -54° 07' | S.W.byW.½W.| | | | | | | | Needle N. | -54° 05' | S.W.byW.½W.| | | | | | | | Needle S. | -53° 58' | S.W.byW.½W.| | | | | | | | Mag. N.S. | -53° 36' | S.W.byW.½W.| | | | | | | | Mag. N. | -55° 17' | W.S.W. | | | | | | | | Mag. S. | -55° 27' | W.S.W. | | | | | | | | Direct. | -54° 47' | W.S.W. | | | | | | | | Needle N. | -55° 22' | W.S.W. | | | | | | | | Needle S. | -55° 39' | S.W. | | | | | | | | Mag. N.S. | -55° 32' | S.W. | | | | | | | | Mag. N. | -55° 15' | S.W. | | | | | | | | Mag. S. | -55° 49' | S.W. | | | | | | | | Direct. | -55° 25' | S.W. | | | | | | | | Needle N. | -55° 31' | S.W. | | | | | | | | Needle S. | -55° 15' | S.W. | | | | | | | | Mag. N.S. | -55° 49' | S.W. | | | | | | | | Mag. N. | -55° 25' | S.W. | | | | | | | | Mag. S. | -55° 31' | S.W. | | | | Corrections: | Ship's attraction. | Index. | Corrected Inclination. | |--------------------|--------|------------------------| | +63 | -26 | -53° 34 | | +80 | -26 | -51° 27 | | +50 | -26 | -51° 16 | | +27 | -26 | -51° 19 | | +18 | -26 | -53° 31 | | +12 | -26 | -54° 12 | | +40 | -26 | -54° 59 | | +24 | -26 | -55° 34 | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Jan. 23 | -50°48'| 10°18'| Direct. | -57°23' s.w.byw.½w. | | | -57°19' | A little motion. | | | | | Needle N. | -57°45' s.w.byw.½w. | | | | | | | | | Needle S. | -57°07' s.w.byw.½w. | | | | | | | | | Mag. N.S. | -57°45' s.w.byw.½w. | | | | | | | | | Mag. N. | -57°28' s.w.byw.½w. | | | | | | | | | Mag. S. | -57°19' s.w.byw.½w. | | | | | | | | | Direct. | -57°25' s.w.byw.½w. | | | | | | | | | Direct. | -57°24' s.w.byw.½w. | | | | Moderate breeze, table steady. | | | | | Needle N. | -57°42' s.w.byw.½w. | | | | | | | | | Direct. | -57°41' s.w.byw.½w. | | | | | | | | | Mag. N.S. | -57°46' s.w.byw.½w. | | | | | | | | | Mag. N. | -57°44' s.w.byw.½w. | | | | | | | | | Direct. | -57°26' s.w.byw.½w. | | | | | | | | | Needle N. | -57°51' s.w.byw.½w. | | | | | | | | | Needle S. | -57°01' s.w.byw.½w. | | | | | | | | | Mag. N.S. | -57°24' s.w.byw.½w. | | | | | | | | | Mag. N. | -57°33' s.w.byw.½w. | | | | | | | | | Mag. S. | -57°21' s.w.byw.½w. | | | | | | | | | Direct. | -57°24' s.w.byw.½w. | | | | | | | | | Direct. | -57°56' w.by n. | | | | | | | | | Needle N. | -57°49' w.by n. | | | | | | | | | Needle S. | -57°02' w.by n. | | | | | | | | | Mag. N.S. | -57°55' w.by n. | | | | | | | | | Mag. N. | -57°05' w.by n. | | | | | | | | | Mag. S. | -57°18' w.by n. | | | | | | | | | Direct. | -57°43' w.by n. | | | | | | | | | Direct. | -57°30' s.s.w.½w. | | | | | | | | | Needle N. | -58°23' s.s.w.½w. | | | | | | | | | Direct. | -57°54' s.s.w.½w. | | | | | | | | | Needle N. | -61°13' s.s.e. | | | | | | | | | Needle S. | -61°41' s.s.e. | | | | | | | | | Mag. N.S. | -60°41' s.s.e. | | | | | | | | | Mag. N. | -61°04' s.s.e. | | | | | | | | | Mag. S. | -60°58' s.s.e. | | | | | | | | | Direct. | -61°26' s.s.e. | | | | | | | | | Direct. | -61°23' s.s.e. | | | | | | | | | Needle N. | -62°56' s.e.by s. | | | | | | | | | Needle S. | -62°41' s.e.by s. | | | | | | | | | Direct. | -62°36' s.e.by s. | | | | | | | | | Needle N. | -63°12' s.e.by s. | | | | | | | | | Needle S. | -63°59' s.e.½e. | | | | | | | | | Direct. | -62°25' s.e.½e. | | | | | | | | | Needle N. | -63°37' s.e.½e. | | | | | | | | | Needle S. | -63°53' s.e.½e. | | | | | | | | | Mag. N.S. | -64°02' s.e.½e. | | | | | | | | | Mag. N. | -63°51' s.e.½e. | | | | | | | | | Mag. S. | -64°09' s.e.½e. | | | | | | | | | Direct. | -65°09' w.s.w. | | | | | | | | | Direct. | -64°49' n.w. | | | | | | | | | Direct. | -65°00' w. | | | | | | | | | Direct. | -64°59' w.s.w. | | | | | | | | | Direct. | -64°44' s.w. | | | | | | | | | Direct. | -64°13' s.w. | | | | | | | | | Needle N. | -64°12' s.w. | | | | | | | | | Needle S. | -63°39' s.w. | | | | | | | | | Needle N.S. | -64°06' s.w. | | | | | | | | | Mag. N. | -63°59' s.w. | | | | | | | | | Mag. S. | -64°06' s.w. | | | | Unsteady. | --- **3D2** ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Feb. 5 | -63°19' | 21°48' | Direct. Needle N. | -65°17' | S.S.E. | -15 | -65°35 | Heavy swell from S.E., light breeze, table steady. | | | | | Needle S. | -64°39' | S.S.E. | | | | | | | | Needle N.S. | -64°29' | S.S.E. | | | | | | | | Mag. N. | -64°39' | S.S.E. | | | | | | | | Mag. S. | -64°46' | S.S.E. | | | | | | | | Direct. | -64°52' | S.S.E. | | | | | | | | | -65°25' | S.S.E. | | | | | Feb. 6 | -64°25' | 24°18' | Direct. Needle N. | -66°17' | S.S.E. ½ E. | -14 | -66°41 | Table steady. | | | | | Needle S. | -66°16' | S.S.E. ½ E. | | | | | | | | Needle N.S. | -65°28' | S.S.E. ½ E. | | | | | | | | Direct. | -65°58' | S.S.E. ½ E. | | | | | | | | | -66°07' | S.S.E. ½ E. | | | | | Feb. 7 | -65°39' | 28°48' | Direct. Needle N. | -67°14' | s. by E. ½ E. | -22 | -67°56 | Table steady. | | | | | Needle S. | -67°19' | s. by E. ½ E. | | | | | | | | Needle N.S. | -66°54' | s. by E. ½ E. | | | | | | | | Mag. N. | -67°05' | s. by E. ½ E. | | | | | | | | Mag. S. | -67°02' | s. by E. ½ E. | | | | | | | | Direct. | -67°10' | s. by E. ½ E. | | | | | | | | | -68°28' | s.e. by E. | | | | | Feb. 8 | -66°27' | 30°45' | Direct. Needle N. | -68°09' | s.e. by E. | +05 | -68°31 | Fresh breeze, table steady. | | | | | Needle S. | -67°49' | s.e. by E. | | | | | | | | Needle N.S. | -68°04' | s.e. by E. | | | | | | | | Mag. N. | -68°08' | s.e. by E. | | | | | | | | Mag. S. | -68°06' | s.e. by E. | | | | | | | | Direct. | -68°26' | s.e. by E. | | | | | | | | | -69°11' | s.e. by E. | | | | | Feb. 9 | -66°36' | 36°50' | Direct. Needle N. | -69°13' | s.e. by E. | +05 | -69°22 | Light breeze, very steady. | | | | | Needle S. | -68°40' | s.e. by E. | | | | | | | | Needle N.S. | -68°47' | s.e. by E. | | | | | | | | Mag. N. | -68°59' | s.e. by E. | | | | | | | | Mag. S. | -69°02' | s.e. by E. | | | | | | | | Direct. | -69°20' | s.e. by E. | | | | | | | | | -70°12' | s. by w. | | | | | Feb. 10 | -67°10' | 38°51' | Direct. Needle N. | -70°53' | s. by w. | -32 | -71°07 | Steady. | | | | | Needle S. | -70°02' | s. by w. | | | | | | | | Needle N.S. | -69°41' | s. by w. | | | | | | | | Mag. N. | -70°00' | s. by w. | | | | | | | | Mag. S. | -70°12' | s. by w. | | | | | | | | Direct. | -70°05' | s. by w. | | | | | | | | | -70°33' | N.E. | +89 | -69°27 | Strong breeze, sailing along a pack of ice, unsteady. | | | | | Needle N. | -70°26' | N.E. | | | | | | | | Needle N. | -69°36' | S. ½ E. | | | | | | | | Needle S. | -69°43' | S. ½ E. | | | | | | | | Needle S. | -68°58' | S. ½ E. | | | | | | | | Needle N.S. | -69°28' | S. ½ E. | | | | | | | | Mag. N. | -69°18' | S. ½ E. | | | | | | | | Mag. S. | -69°03' | S. ½ E. | | | | | | | | Direct. | -69°28' | S. ½ E. | | | | | | | | | -70°12' | E.N.E. | | | | | | | | Needle N. | -70°28' | E.N.E. | | | | | | | | Needle S. | -69°54' | E.N.E. | | | | | | | | Needle N.S. | -70°08' | E.N.E. | | | | | | | | Mag. N. | -70°14' | E.N.E. | | | | | | | | Mag. S. | -70°06' | E.N.E. | | | | | | | | Direct. | -70°13' | E.N.E. | | | | | | | | | | | | | A swell from the eastward, table unsteady. | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |------------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | **1845.** | | | | | | | | | | Feb. 14. | -66° 24' | 40° 01' | Direct. Needle N. | -70° 38' N.E. by N. | | | | | | | | | Needle S. Direct. | -70° 07' N.E. by N. | | | | | | | | | Needle N. Direct. | -70° 10' N.E. by N. | | | | | | | | | Needle S. Direct. | -70° 17' N.E. by N. | | | | | | | | | Needle N. s.by E. | -68° 03' s.by E. | | | | | | | | | Needle S. s.by E. | -68° 13' s.by E. | | | | | | | | | Needle N.S. s.by E.| -67° 20' s.by E. | | | | | | | | | Mag. N. s.by E. | -68° 10' s.by E. | | | | | | | | | Mag. S. s.by E. | -67° 52' s.by E. | | | | | | | | | Direct. | -68° 06' s.by E. | | | | | | | | | Needle N. | -69° 58' N. | | | | | | | | | Needle S. | -70° 02' N. | | | | | | | | | Needle N.S. | -69° 22' N. | | | | | | | | | Mag. N. | -68° 50' N. | | | | | | | | | Mag. S. | -68° 25' N. | | | | | | | | | Direct. | -68° 30' N. | | | | | | | | | Needle N. | -68° 50' N. | | | | | | | | | Needle S. | -70° 13' E.by S. | | | | | | | | | Needle N.S. | -69° 52' E.by S. | | | | | | | | | Direct. | -70° 29' S.E.by E. | | | | | | | | | Needle N. | -69° 51' S.E.by E. | | | | | | | | | Needle S. | -69° 39' S.E.by E. | | | | | | | | | Needle N.S. | -69° 54' S.E.by E. | | | | | | | | | Direct. | -69° 54' S.E. | | | | | | | | | Needle N. | -69° 53' S.E. | | | | | | | | | Needle S. | -69° 06' S.E. | | | | | | | | | Needle N.S. | -69° 50' S.E. | | | | | | | | | Direct. | -69° 38' S.E. | | | | | | | | | Needle N. | -69° 39' S.E. | | | | | | | | | Needle S. | -69° 03' S.E. | | | | | | | | | Needle N.S. | -69° 43' S.E. | | | | | | | | | Direct. | -70° 01' S.E. | | | | | | | | | Needle N. | -70° 02' S.E. | | | | | | | | | Needle S. | -69° 34' S.E. | | | | | | | | | Needle N.S. | -69° 32' S.E. | | | | | | | | | Mag. N. | -69° 37' S.E. | | | | | | | | | Mag. S. | -69° 32' S.E. | | | | | | | | | Direct. | -70° 00' S.E. | | | | | | | | | Needle N. | -70° 44' S.E. | | | | | | | | | Needle S. | -70° 22' S.E. | | | | | | | | | Needle N.S. | -69° 58' S.E. | | | | | | | | | Mag. N. | -70° 08' S.E. | | | | | | | | | Mag. S. | -70° 08' S.E. | | | | | | | | | Direct. | -70° 42' S.E. | | | | | | | | | Needle N. | -71° 03' S.E. | | | | | | | | | Needle S. | -71° 24' S.E. | | | | | | | | | Needle N.S. | -70° 26' S.E. | | | | | | | | | Direct. | -70° 40' S.E. | | | | | | | | | Needle N. | -71° 01' S.E. | | | | | | | | | Needle S. | -71° 22' S.E. | | | | | | | | | Needle N.S. | -70° 30' S.E. | | | | | | | | | Mag. N. | -70° 43' S.E. | | | | | | | | | Mag. S. | -70° 29' S.E. | | | | | | | | | Direct. | -70° 40' S.E. | | | | | **Corrections:** | Ship's attraction. | Index. | Corrected Inclination. | |--------------------|--------|------------------------| | +89 | -26 | -69° 15 | | | | | | +76 | -26 | -68° 18 | | | | | | +10 | -26 | -70° 14 | | | | | | -10 | -26 | -70° 21 | | | | | | -05 | -26 | -70° 49 | | | | | | -07 | -26 | -71° 26 | | | | | | -13 | -26 | -71° 27 | **Remarks:** - Very squally, with thick weather, table unsteady. - A heavy swell, unsteady. - Calm, a heavy sea, not steady. - Observed the inner circle to have moved, table very unsteady. - Strong breezes, with a heavy sea running. - Much motion. - Icchlink to the southward, fresh breezes, table unsteady. - No ice in sight, unsteady. - Fresh breeze, table steady. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|--------------------------| | Feb. 27 | -61° 10' | 64° 20' | Direct. Needle N. | -71° 20' | S.S.E. 3/4 E. | -26 | -72° 18' | Very unsteady. | | | | | Needle S. | -71° 48' | S.S.E. 3/4 E. | | | | | | | | Direct. Needle N.| -71° 10' | S.S.E. 3/4 E. | | | | | | | | Needle S. | -72° 44' | S.S.E. | | | | | | | | Needle N. | -72° 49' | S.S.E. | | | | | | | | Needle S. | -72° 36' | S.S.E. | | | | | | | | Needle N.S. | -72° 43' | S.S.E. | | | Table steady. | | | | | Mag. N. | -72° 34' | S.S.E. | | | | | | | | Mag. S. | -72° 18' | S.S.E. | | | | | | | | Direct. Needle N.| -72° 45' | S.S.E. | | | | | | | | Needle N. | -73° 01' | S.S.E. | | | | | | | | Needle S. | -72° 12' | S.S.E. | | | Steady. | | | | | Needle N.S. | -72° 35' | S.S.E. | | | | | Mar. 1 | -62° 10' | 72° 25' | Direct. Needle N.| -73° 37' | S.E. by s. | -26 | -74° 33' | Calm, table steady. | | | | | Needle S. | -73° 54' | S.E. by s. | | | | | | | | Needle N.S. | -73° 25' | S.E. by s. | | | | | | | | Mag. N. | -73° 42' | S.E. by s. | | | | | | | | Mag. S. | -73° 39' | S.E. by s. | | | | | | | | Direct. Needle N.| -73° 45' | S.E. by s. | | | | | | | | Needle S. | -73° 41' | s. by E. 1/2 E. | | | | | | | | Needle N.S. | -73° 39' | s. by E. 1/2 E. | | | | | | | | Mag. N. | -73° 45' | s. by E. 1/2 E. | | | | | | | | Mag. S. | -73° 48' | s. by E. 1/2 E. | | | | | | | | Direct. Needle N.| -74° 11' | s. by E. 1/2 E. | | | | | | | | Needle S. | -74° 21' | s. | | | | | | | | Needle N.S. | -73° 43' | s. | | | Steady breeze, table steady. | | | | | Direct. Needle N.| -73° 58' | s. | | | | | | | | Needle S. | -74° 10' | s. | | | | | | | | Needle N.S. | -75° 02' | s. by w. 1/2 W. | | | Squalls of snow, fresh breeze, unsteady. | | | | | Direct. Needle N.| -74° 56' | s. by w. 1/2 W. | | | | | | | | Needle S. | -74° 39' | s. by w. 1/2 W. | | | | | | | | Needle N.S. | -74° 41' | s. by w. 1/2 W. | | | | | | | | Direct. Needle N.| -74° 56' | s. by w. 1/2 W. | | | | | | | | Needle S. | -76° 13' | S.E. 1/2 E. | | | Table very unsteady, a strong breeze, aurora visible. | | | | | Needle N.S. | -76° 40' | S.E. 1/2 E. | | | | | | | | Direct. Needle N.| -76° 18' | S.E. 1/2 E. | | | | | | | | Needle S. | -75° 59' | S.E. 1/2 E. | | | | | | | | Needle N.S. | -76° 06' | S.E. 1/2 E. | | | | | | | | Direct. Needle N.| -76° 21' | S.E. | | | | | | | | Needle S. | -76° 41' | S.E. | | | Very unsteady. | | | | | Needle N.S. | -76° 06' | S.E. | | | | | | | | Mag. N. | -75° 46' | S.E. | | | | | | | | Mag. S. | -75° 56' | S.E. | | | | | | | | Direct. Needle N.| -76° 16' | S.E. | | | | | | | | Needle S. | -76° 26' | S.E. | | | | | | | | Needle N.S. | -76° 26' | S.S.W. | | | | | | | | Direct. Needle N.| -77° 02' | S.S.W. | | | | | | | | Needle S. | -76° 12' | S.S.W. | | | | | | | | Needle N.S. | -76° 28' | S.S.W. | | | | | | | | Mag. N. | -76° 13' | S.S.W. | | | | | | | | Mag. S. | -76° 35' | S.S.W. | | | | | | | | Direct. Needle N.| -76° 26' | S.S.W. | | | | | | | | Needle S. | -78° 11' | E. by s. | | | | | | | | Needle N.S. | -77° 39' | E.S.E. | | | | | | | | Direct. Needle N.| -76° 55' | E.S.E. | | | | | | | | Needle S. | -76° 39' | E.S.E. | | | | | | | | Needle N.S. | -76° 59' | E.S.E. | | | | | | | | Direct. Needle N.| -78° 24' | +13 | | | | | | | | Needle S. | -77° 29' | 00 | | | | | | | | Needle N.S. | -77° 57' | | | | | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | 1845 Mar. 9 | -60° 30' | 92° 34' | Direct. Needle N. | -77° 12' E.S.E. | -0° 01' | -26° | -77° 37' | Very unsteady, aurora visible. | | | | | Needle S. | -77° 31' S.E. by E. | | | | | | | | | Needle N.S. | -76° 49' S.E. by E. | | | | | | | | | Direct. Needle N. | -76° 26' S.E. by E. | | | | | | | | | Needle S. | -76° 41' S.E. by E. | | | | | | | | | Direct. Needle N. | -77° 10' S.E. by E. | | | | | | | | | Needle S. | -77° 25' S.E. by E. | | | | | | | | | Direct. Needle N. | -76° 45' S.E. by E. | | | | | | | | | Needle S. | -77° 01' S.E. by E. | | | | | | | | | Direct. Needle N. | -79° 30' E. ½ N. | | | | | | | | | Needle S. | -79° 13' E. ½ N. | | | | | | | | | Needle N.S. | -79° 29' E. ½ N. | | | | | | | | | Mag. N. | -79° 08' E. ½ N. | | | | | | | | | Mag. S. | -79° 45' E. ½ N. | | | | | | | | | Direct. Needle N. | -79° 43' E. ½ N. | | | | | | | | | Needle S. | -79° 35' E. ½ N. | | | | | | | | | Direct. Needle N. | -78° 30' E.N.E. | | | | | | | | | Needle S. | -78° 04' E.N.E. | | | | | | | | | Direct. Needle N. | -78° 00' E.N.E. | | | | | | | | | Needle S. | -78° 20' E.N.E. | | | | | | | | | Direct. Needle N. | -78° 04' E. by s. | | | | | | | | | Needle S. | -78° 21' E. by s. | | | | | | | | | Needle N.S. | -77° 33' E. by s. | | | | | | | | | Direct. Needle N. | -77° 54' E. by s. | | | | | | | | | Needle S. | -77° 58' E. by s. | | | | | | | | | Direct. Needle N. | -78° 30' E.N.E. | | | | | | | | | Needle S. | -78° 53' E.N.E. | | | | | | | | | Needle N.S. | -78° 31' E.N.E. | | | | | | | | | Direct. Needle N. | -78° 53' E.N.E. | | | | | | | | | Needle S. | -78° 30' E.N.E. | | | | | | | | | Direct. Needle N. | -79° 32' E. | | | | | | | | | Needle S. | -79° 29' E. | | | | | | | | | Needle N.S. | -78° 48' E. | | | | | | | | | Direct. Needle N. | -78° 55' E. | | | | | | | | | Needle S. | -79° 13' E. | | | | | | | | | Direct. Needle N. | -79° 17' E. by s. | | | | | | | | | Needle S. | -79° 31' E. by s. | | | | | | | | | Needle N.S. | -78° 38' E. by s. | | | | | | | | | Direct. Needle N. | -78° 56' E. by s. | | | | | | | | | Needle S. | -79° 10' E. by s. | | | | | | | | | Direct. Needle N. | -78° 38' N.E. | | | | | | | | | Needle S. | -78° 51' N.E. | | | | | | | | | Needle N.S. | -78° 39' N.E. | | | | | | | | | Direct. Needle N. | -78° 50' N.E. | | | | | | | | | Needle S. | -78° 25' N.E. | | | | | | | | | Needle N.S. | -78° 04' N.E. | | | | | | | | | Direct. Needle N. | -78° 26' N.E. | | | | | | | | | Needle S. | -78° 30' N.E. | | | | | | | | | Direct. Needle N. | -77° 14' N.E. ½ N. | | | | | | | | | Needle S. | -77° 25' N.E. ½ N. | | | | | | | | | Needle N.S. | -77° 01' N.E. ½ N. | | | | | | | | | Mag. N. | -76° 55' N.E. ½ N. | | | | | | | | | Mag. S. | -76° 51' N.E. ½ N. | | | | | | | | | Direct. Needle N. | -76° 45' N.E. ½ N. | | | | | | | | | Needle S. | -76° 45' N.E. ½ N. | | | | | | | | | Needle N.S. | -76° 55' N.E. ½ N. | | | | | | | | | Mag. N. | -76° 51' N.E. ½ N. | | | | | | | | | Mag. S. | -76° 45' N.E. ½ N. | | | | | **Corrections:** - Ship's attraction: -0° 01' - Ship's Index: -26° **Corrected Inclination:** - -77° 37' to -77° 33' **Remarks:** - Very unsteady, aurora visible. - Table unsteady, aurora still visible. - A heavy sea, very unsteady. - 6 a.m. The aurora seem faintly, very unsteady. - A.m. Aurora visible, unsteady; squally, with snow. - Unsteady. - Heavy squalls, unsteady. - A strong gale, very unsteady. - Unsteady, a heavy swell from the westward, strong breeze. - Too unsteady to continue the observation. - Very unsteady. | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |------------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | 1845. Mar.22. | -47° 21' | 115° 15' | Direct. Needle N. | -76° 42' | N.W. 3/4 N. | +85 | -75° 32' | Light breeze, table steady, thick fog. | | | | | Needle S. | -76° 31' | N.W. 3/4 N. | | | | | | | | Needle N.S. | -76° 11' | N.W. 3/4 N. | | | | | | | | Mag. N. | -76° 28' | N.W. 3/4 N. | | | | | | | | Mag. S. | -76° 38' | N.W. 3/4 N. | | | | | | | | Direct. Needle N. | -76° 29' | N.W. 3/4 N. | | | | | | | | Needle S. | -76° 38' | N.W. 3/4 N. | | | | | | | | Direct. | -74° 31' | N. by E. | +79 | -73° 27' | A heavy sea, ship pitching heavily, very unsteady. | | | | | Needle N. | -74° 12' | N. by E. | | | | | | | | Needle S. | -74° 02' | N. by E. | | | | | | | | Direct. | -74° 37' | N. by E. | | | | | | | | Needle N. | -73° 25' | N. 1/2 E. | | | | | | | | Needle S. | -73° 10' | N. 1/2 E. | | | | | | | | Needle N.S. | -72° 56' | N. 1/2 E. | +76 | -72° 10' | A heavy westerly swell, unsteady. | | | | | Mag. N. | -72° 18' | N. 1/2 E. | | | | | | | | Mag. S. | -72° 26' | N. 1/2 E. | | | | | | | | Direct. Needle N. | -72° 46' | N. 1/2 E. | | | | | | | | Needle S. | -72° 09' | N. by W. | | | | | | | | Needle N. | -71° 50' | N. by W. | +80 | -71° 14' | A heavy westerly swell. | | | | | Needle S. | -71° 55' | N. by W. | | | | | | | | Needle N.S. | -72° 44' | N. by W. | | | | | | | | Mag. N. | -72° 00' | N. by W. | | | | | | | | Mag. S. | -72° 12' | N. by W. | | | | | | | | Direct. Needle N. | -72° 09' | N. by W. | | | | | | | | Needle S. | -69° 08' | N. by E. | +81 | -68° 04' | Table steady. | | | | | Needle N. | -69° 08' | N. by E. | | | | | | | | Needle S. | -68° 38' | N. by E. | | | | | | | | Needle N.S. | -68° 59' | N. by E. | | | | | | | | Direct. Needle N. | -69° 03' | N. by E. | | | | | | | | Needle S. | -67° 24' | N. by E. | | | | | | | | Needle N. | -67° 37' | N. by E. | +80 | -66° 21' | Table steady, cloudy. | | | | | Needle S. | -66° 52' | N. by E. 1/2 E. | | | | | | | | Needle N.S. | -67° 14' | N. by E. 1/2 E. | | | | | | | | Mag. N. | -67° 08' | N. by E. 1/2 E. | | | | | | | | Mag. S. | -67° 18' | N. by E. 1/2 E. | | | | | | | | Direct. Needle N. | -66° 53' | N.N.E. | +84 | -66° 00' | Unsteady. | | | | | Needle S. | -67° 11' | N.N.E. | | | | | | | | Needle N. | -66° 51' | N.N.E. | | | | | | | | Needle S. | -66° 57' | N.N.E. | | | | | | | | Needle N.S. | -66° 15' | N.N.E. | | | | | | | | Direct. Needle N. | -66° 25' | N.N.E. | +84 | -65° 24' | Unsteady. | | | | | Needle S. | -66° 50' | N.N.E. | | | | | | | | Needle N.S. | -65° 59' | N.N.E. | | | | | | | | Direct. Needle N. | -64° 42' | N.N.E. | | | | | | | | Needle S. | -64° 39' | N.N.E. | | | | | | | | Needle N.S. | -64° 08' | N.N.E. | | | | | | | | Mag. N. | -64° 39' | N.N.E. | | | | | | | | Mag. S. | -64° 18' | N.N.E. | | | | | | | | Direct. Needle N. | -64° 29' | N.N.E. | | | | | | | | Needle S. | -65° 22' | N.N.E. | | | | | | | | Needle N. | -65° 04' | N.N.E. | | | | | | | | Needle S. | -64° 48' | N.N.E. | | | | | | | | Needle N.S. | -65° 13' | N.N.E. | +18 | -64° 52' | At the tents, King George's Sound. | | | | | Mag. N. | -65° 11' | N.N.E. | | | | | | | | Mag. S. | -65° 15' | N.N.E. | | | | * Needle A. Face east ............ 64° 29' Face west ............ 65° 13' Needle B. Face west ............ 65° 13' Face east ............ 65° 10' ### Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | 1845. | | | | | | | | | | Apr. 12. | -35° 02 | 117° 56 | Direct. | -65° 34' | | | | | | | | | Needle N. | -65° 39' | | | | | | | | | Needle S. | -65° 07' | | | | | | | | | Needle N.S. | -65° 25' | | | | | | | | | Mag. N. | -65° 21' | | | | | | | | | Mag. S. | -65° 23' | | | | | | | | | Direct. | -65° 15' | | | | | | | | | Needle N. | -64° 55' | | | | | | | | | Needle S. | -64° 32' | | | | | | | | | Direct. | -65° 15' | | | | | | | | | Direct. | -66° 29' s.e. by E.| | +12 | -65° 59' | Unsteady.| | | | | Direct. | -65° 58' s.by E. | | -18 | -65° 59' | | | | | | Direct. | -66° 33' n.w. | | +18 | -64° 54' | Very unsteady.| | | | | Needle N. | -67° 30' n.w. | | | | | | | | | Needle S. | -66° 30' n.w. | | | | | | | | | Needle N.S. | -66° 35' n.w. | | | | | | | | | Direct. | -66° 30' n.w. | | | | | | | | | Direct. | -64° 03' n.w. by N. | | +88 | -62° 22' | Moderate breeze, table steady.| | | | | Needle N. | -64° 22' n.w. by N. | | | | | | | | | Needle S. | -63° 31' n.w. by N. | | | | | | | | | Needle N.S. | -63° 58' n.w. by N. | | | | | | | | | Mag. N. | -64° 43' n.w. by N. | | | | | | | | | Mag. S. | -64° 06' n.w. by N. | | | | | | | | | Direct. | -64° 13' n.w. by N. | | | | | | | | | Direct. | -60° 10' w.n.w. | | | | | | | | | Needle N. | -60° 56' w.n.w. | | | | | | | | | Needle S. | -60° 16' w.n.w. | | | | | | | | | Needle N.S. | -60° 30' w.n.w. | | | | | | | | | Direct. | -60° 53' w.n.w. | | | | | | | | | Direct. | -58° 47' w. by N. | | | | | | | | | Needle N. | -58° 46' w. by N. | | | | | | | | | Needle S. | -58° 51' w. by N. | | | | | | | | | Needle N.S. | -58° 24' w. by N. | | | | | | | | | Mag. N. | -58° 53' w. by N. | | | | | | | | | Mag. S. | -58° 53' w. by N. | | | | | | | | | Direct. | -58° 43' w. by N. | | | | | | | | | Direct. | -56° 54' n.w. | | | | | | | | | Needle N. | -56° 54' n.w. | | | | | | | | | Needle S. | -56° 41' n.w. | | | | | | | | | Direct. | -56° 54' n.w. | | | | | | | | | Direct. | -55° 48' n.w. | | | | | | | | | Needle N. | -55° 30' n.w. | | | | | | | | | Needle S. | -55° 22' n.w. | | | | | | | | | Needle N.S. | -55° 28' n.w. | | | | | | | | | Direct. | -55° 37' w. ½ N. | | | | | | | | | Needle N. | -55° 58' w. ½ N. | | | | | | | | | Needle S. | -55° 01' w. ½ N. | | | | | | | | | Needle N.S. | -55° 32' w. ½ N. | | | | | | May 1. | -23° 58 | 99° 06 | Direct. | -65° 11'5 | | | | | | | | | Needle N. | -65° 16' | | | | | | | | | Needle S. | -65° 10' | | | | | | | | | Needle N.S. | -65° 23' | | | | | * Captain Fitzroy having left a memorandum at King George's Sound stating that he had found local magnetic disturbance at King George's Sound, the Inclination was observed on the opposite side of the bay, on the same day as at the tents: needle B gave as follows (no correction being here applied for Index in either case): At the tents. Face west............. -65° 15' Face east .............. -65° 10' Mean........... -65° 11'5 On the opposite side of the bay. Face west............. -65° 16' Face east .............. -65° 30' Mean........... -65° 23' The distance between the two stations was between three and four miles. MDCCXLVI. | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |------------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|--------------------------| | 1845 May 3 | -23° 50' | 95° 56' | Direct. Needle N. | -55° 38' | W. 1/2 N. | +56 | -54° 26' | Unsteady | | | | | Needle S. | -56° 17' | W. 1/2 N. | | | | | | | | Needle N.S. | -55° 00' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -55° 38' | W. 1/2 N. | | | | | | | | Needle S. | -55° 48' | W. 1/2 N. | | | | | | | | Needle N.S. | -55° 43' | W.N.W. | | | | | | | | Direct. Needle N.| -56° 08' | W.N.W. | | | | | | | | Needle S. | -55° 08' | W.N.W. | | | | | | | | Needle N.S. | -55° 33' | W.N.W. | | | | | | | | Direct. Needle N.| -55° 35' | W.N.W. | | | | | | | | Needle S. | -54° 42' | N.W. | | | | | | | | Needle N.S. | -54° 39' | N.W. | | | Cross sea, with rolling motion. | | | | | Direct. Needle N.| -54° 33' | N.W. | | | | | | | | Needle S. | -53° 33' | N.W. | | | | | | | | Needle N.S. | -53° 47' | N.W. | | | Cross sea, with rolling motion. | | | | | Direct. Needle N.| -53° 03' | N.W. | | | | | | | | Needle S. | -53° 19' | N.W. | | | | | | | | Needle N.S. | -52° 48' | W. 1/2 N. | | | Very unsteady. | | | | | Direct. Needle N.| -52° 18' | W. 1/2 N. | | | | | | | | Needle S. | -51° 58' | W. 1/2 N. | | | | | | | | Needle N.S. | -51° 00' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -50° 45' | W. 1/2 N. | | | | | | | | Needle S. | -50° 37' | W. 1/2 N. | | | | | | | | Needle N.S. | -50° 16' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -50° 18' | W. 1/2 N. | | | | | | | | Needle S. | -50° 20' | W. 1/2 N. | | | | | | | | Needle N.S. | -50° 20' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -50° 31' | W. 1/2 N. | | | | | | | | Needle S. | -50° 19' | W. 1/2 N. | | | | | | | | Needle N.S. | -50° 29' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -50° 10' | W. 1/2 N. | | | | | | | | Needle S. | -50° 03' | W. 1/2 N. | | | | | | | | Needle N.S. | -50° 41' | W. 1/2 N. | | | | | | | | Direct. Needle N.| -50° 17' | W. 1/2 N. | | | | | | | | Needle S. | -50° 15' | W. 1/2 N. | | | | | | | | Needle N.S. | -50° 46' | S. | | | | | | | | Direct. Needle N.| -50° 42' | S.S.W. | | | | | | | | Needle S. | -50° 05' | S.S.W. | | | | | | | | Needle N.S. | -50° 10' | S.W. | | | | | | | | Direct. Needle N.| -50° 57' | S.W. | | | | | | | | Needle S. | -50° 11' | W.S.W. | | | | | | | | Needle N.S. | -50° 30' | W.S.W. | | | | | | | | Direct. Needle N.| -50° 06' | W. | | | | | | | | Needle S. | -50° 34' | W. | | | | | | | | Needle N.S. | -50° 01' | W.N.W. | | | | | | | | Direct. Needle N.| -50° 30' | W.N.W. | | | | | | | | Needle S. | -50° 23' | N.W. | | | | | | | | Needle N.S. | -50° 59' | N.W. | | | | | | | | Direct. Needle N.| -50° 38' | N.N.W. | | | | | | | | Needle S. | -50° 31' | N.N.W. | | | | | | | | Needle N.S. | -50° 49' | N. | | | | The observations at N.W., N.N.W., and N. have not been included in the mean. Light air, table steady. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed. | Observed Inclination. | Ship's head. | Corrections. | Corrected Inclination. | Remarks | |------------|------|-------|------------------|-----------------------|--------------|--------------|------------------------|---------| | **1845.** | | | | | | | | | | May 12. | -20°44' | 78°31' | Direct. | -52°58' | N.E. | +68 | -51°33' | | | | | | Needle N. | -53°04' | N.N.E. | +18 | -51°33' | | | | | | Direct. | -53°18' | N.E. | +86 | -51°40' | | | | | | Needle N. | -53°30' | N.E. | +18 | -51°40' | | | | | | Direct. | -53°15' | E.N.E. | +72 | -52°02' | | | | | | Needle N. | -53°49' | S.E. | +30 | -52°34' | | | | | | Direct. | -53°15' | S.E. | +18 | -52°34' | | | | | | Needle N. | -53°29' | E. | +51 | -52°15' | | | | | | Direct. | -53°25' | E. | +18 | -52°15' | | | | | | Needle N. | -53°41' | N.E. | +86 | -51°42' | | | | | | Direct. | -53°05' | N.E. | +18 | -51°42' | | | | | | Needle N. | -53°47' | N. | +72 | -51°28' | | | | | | Direct. | -52°42' | N. | +18 | -51°28' | | | | | | Needle N. | -53°13' | N.W. | +86 | -51°30' | | | | | | Direct. | -52°58' | N.W. | +18 | -51°30' | | | | | | Needle N. | -53°30' | W. | +51 | -52°16' | | | | | | Direct. | -53°27' | W. | +18 | -52°16' | | | | | | Needle N. | -53°41' | W. by N. | +62 | -52°19' | Unsteady.| | | | | Needle N. | -53°52' | W. by N. | +18 | -52°19' | Unsteady.| | | | | Needle S. | -53°49' | W. by N. | +62 | -52°44' | Very unsteady.| | | | | Needle N.S. | -53°15' | W. by N. | +18 | -52°44' | Very unsteady.| | | | | Direct. | -53°30' | W. by N. | +62 | -52°44' | Very unsteady.| | | | | Needle N. | -54°05' | W. by N. | +18 | -53°18' | Very unsteady.| | | | | Needle S. | -54°10' | W. by N. | +37 | -53°18' | Very unsteady.| | | | | Needle N.S. | -53°52' | W. by N. | +18 | -53°18' | Very unsteady.| | | | | Direct. | -54°01' | W. by N. | +62 | -53°01' | Unsteady.| | | | | Needle N. | -54°10' | W. by N. | +18 | -53°01' | Unsteady.| | | | | Needle N. | -54°41' | S.W. by W. | +62 | -53°46' | Steady.| | | | | Needle S. | -54°23' | S.W. by W. | +18 | -53°46' | Steady.| | | | | Needle N.S. | -54°00' | S.W. by W. | +62 | -53°59' | Table unsteady.| | | | | Mag. N. | -53°58' | S.W. by W. | +18 | -53°59' | Table unsteady.| | | | | Mag. S. | -54°15' | S.W. by W. | +62 | -53°49' | Unsteady.| | | | | Direct. | -54°09' | S.W. by W. | +18 | -53°49' | Unsteady.| | | | | Needle N. | -54°06' | S.W. by W. | +62 | -53°53' | Table steady.| | | | | Needle N. | -54°21' | W. by N. | +18 | -53°53' | Table steady.| ### Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head. | Corrections. | Corrected Inclination. | Remarks | |----------|------|-------|-----------------|----------------------|--------------|---------------|------------------------|---------| | **May 27, 1845** | -20° 09' | 57° 31' | Direct. Needle N. | -53° 53' | -53° 38' | On shore at Mauritius. | | | | | Needle S. | -54° 27' | +18 | -53° 38' | | | | | Needle N.S. | -53° 29' | | -53° 38' | | | | | Mag. N. | -53° 57' | | -53° 38' | | | | | Mag. S. | -53° 52' | | -53° 38' | | **June 3** | -26° 26' | 48° 20' | Direct. Needle N. | -55° 50' | s.w. by w. | Unsteady. | | | | | Needle S. | -56° 20' | +32 | -54° 51' | | | | | Needle N.S. | -55° 05' | +18 | -54° 51' | | | | | Direct. Needle N. | -55° 30' | s.w. by w. | Unsteady. | | | | | Needle S. | -60° 20' | +80 | -58° 46' | | | | | Needle N.S. | -60° 40' | +18 | -58° 46' | | | | | Direct. Needle N. | -59° 57' | n.w. by w. | Very unsteady. | | | | | Needle S. | -60° 38' | +80 | -58° 32' | | | | | Needle N.S. | -60° 02' | +18 | -58° 32' | | **May 30** | -27° 14' | 45° 50' | Direct. Needle N. | -60° 46' | n.w. by w. | Very unsteady. | | | | | Needle S. | -59° 18' | +50 | -59° 14' | | | | | Needle N.S. | -60° 32' | +18 | -59° 14' | | | | | Direct. Needle N. | -59° 48' | n.w. by w. | Steady. | | | | | Needle S. | -60° 02' | +80 | -58° 10' | | | | | Needle N.S. | -60° 30' | +18 | -58° 10' | | | | | Direct. Needle N. | -59° 51' | w. | Very unsteady, a heavy sea. | | | | | Needle S. | -61° 40' | +38 | -57° 24' | | | | | Needle N.S. | -60° 08' | +18 | -57° 24' | | | | | Mag. N. | -60° 02' | | -57° 24' | | | | | Mag. S. | -58° 12' | | -57° 24' | | **June 8** | -28° 02' | 42° 40' | Direct. Needle N. | -58° 03' | w.n.w. | Very unsteady. | | | | | Needle S. | -58° 59' | +72 | -56° 37' | | | | | Needle N.S. | -59° 04' | +18 | -56° 37' | | | | | Mag. N.S. | -57° 33' | +38 | -56° 37' | | | | | Direct. Needle N. | -60° 12' | w. by s. | Very unsteady. | | | | | Needle S. | -58° 55' | +18 | -55° 31' | | | | | Needle N.S. | -56° 56' | +62 | -55° 31' | | | | | Mag. N.S. | -57° 00' | +18 | -55° 31' | | | | | Direct. Needle N. | -56° 39' | w. by n. | | | | | | Needle S. | -56° 49' | +27 | -53° 45' | | | | | Needle N.S. | -53° 29' | +18 | -53° 45' | | **June 11** | -30° 27' | 33° 41' | Direct. Needle N. | -54° 55' | s. | | | | | | Needle S. | -54° 43' | +26 | -53° 37' | | | | | Needle N.S. | -54° 59' | +18 | -53° 37' | | | | | Direct. Needle N. | -54° 38' | e. | | | | | | Needle S. | -54° 44' | +51 | -53° 32' | | | | | Needle N.S. | -54° 40' | +18 | -53° 32' | | | | | Direct. Needle N. | -55° 01' | n.e. | | | | | | Needle S. | -54° 31' | +87 | -53° 06' | | | | | Needle N.S. | -54° 59' | +18 | -53° 06' | | | | | Direct. Needle N. | -54° 45' | n.w. | | | | | | Needle S. | -54° 54' | +88 | -53° 00' | | | | | Needle N.S. | -54° 46' | +18 | -53° 00' | | | | | Direct. Needle N. | -54° 51' | w. | | | | | | Needle S. | -53° 53' | +51 | -53° 39' | | **June 13** | -31° 06' | 31° 26' | Direct. Needle N. | -54° 43' | s.e. | | | | | | Needle S. | -54° 59' | +26 | -53° 37' | | | | | Needle N.S. | -54° 38' | +18 | -53° 37' | | | | | Direct. Needle N. | -54° 44' | e. | | | | | | Needle S. | -54° 40' | +51 | -53° 32' | | | | | Needle N.S. | -55° 01' | +18 | -53° 32' | | | | | Direct. Needle N. | -54° 31' | n.e. | | | | | | Needle S. | -54° 59' | +87 | -53° 06' | | | | | Needle N.S. | -54° 45' | +18 | -53° 06' | | | | | Direct. Needle N. | -54° 54' | n.w. | | | | | | Needle S. | -54° 46' | +88 | -53° 00' | | | | | Needle N.S. | -54° 51' | +18 | -53° 00' | | | | | Direct. Needle N. | -53° 53' | w. | | | | | | Needle S. | -54° 24' | +51 | -53° 39' | | | | | Needle N.S. | -53° 12' | +18 | -53° 39' | | | | | Mag. N.S. | -54° 09' | | -53° 39' | *Simon's Bay, Cape of Good Hope, for local attraction.* *On shore in the Dockyard, in Simon's Bay.* ### Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed. | Observed Inclination. | Ship's head. | Corrections. | Corrected Inclination. | Remarks | |------------|------|-------|------------------|-----------------------|--------------|--------------|------------------------|---------| | **1845.** | | | | | | | | | | June 30. | -33°56' | 18°29' | Direct. | -53°56' | | | | | | | | | Needle N. | -54°15' | | | | | | | | | Needle S. | -52°47' | | | | | | | | | Mag. N.S. | -54°06' | | | | | | | | | Mag. N. | -53°29' | | | | | | | | | Mag. S. | -53°23' | | | | | | | | | Direct. | -53°41' | | | | | | July 2. | -33°56' | 18°29' | Needle N. | -54°11' | | | | | | | | | Needle S. | -52°55' | | | | | | | | | Mag. N.S. | -54°15' | | | | | | | | | Mag. N. | -53°49' | | | | | | | | | Mag. S. | -53°41' | | | | | | | | | Direct. | -53°59' | | | | | | 11. | -33°56' | 18°29' | Needle N. | -54°08' | | | | | | | | | Needle S. | -53°17' | | | | | | | | | Mag. N.S. | -54°12' | | | | | | | | | Mag. N. | -53°54' | | | | | | | | | Mag. S. | -53°59' | | | | | Observed at the Magnetic Observatory, Cape of Good Hope. Observations of the Inclination made on board Her Majesty's hired Bark "Pagoda," with Needle 1 (Fox No. 1). Face West. Time usually two hours before Noon. Observer, Lieut. H. Clerk, Royal Artillery. | Date | Lat. | Long. | Method employed. | Observed Inclination. | Ship's head. | Corrections. | Corrected Inclination. | Remarks | |----------|--------|-------|------------------|-----------------------|--------------|--------------|------------------------|---------| | 1844. Nov. 10. | Magnetic Observatory, Cape of Good Hope. | -33° 56' 18° 29' | Direct. N. | -53° 56' | -53° 25' | Observed on shore. | +08 | -53° 31' | Needle A. used as deflector, adjusted at 40° from the apparent dip. | | | | | S. | -53° 37' | | | | | | | | | Direct. N. | -53° 53' | | | | | | | | | S. | -53° 25' | | | | | | | | | S. | -53° 37' | | | | | | Dec. 19. | -34° 12' 18° 26' | Direct. N. | -54° 15' | -53° 43' | -53° 55' | Observed on shore. | +08 | -53° 50' | Observed in the dock-yard at Simon's Bay. | | | | | S. | -53° 55' | | | | | | 1845. Jan. 9. | Working out of False Bay. | Direct. N. | -54° 28' s.e.by s.½ s. | -54° 03' s.e.by s.½ s. | +22 | +08 | -53° 48' | A strong south-east wind, table very unsteady 2 p.m. | | | | | S. | -54° 25' s.e.by s.½ s. | | | | | | | | | Direct. N. | -54° 48' w.½ s. | | | | | | | | | S. | -53° 58' w.½ s. | | | | | | | | | S. | -54° 10' w.½ s. | | | | | | | | | Direct. N. | -54° 18' w. by N. | | | | | | | | | N. | -53° 48' w. by N. | | | | | | | | | S. | -54° 08' w. by N. | | | | | | | | | Direct. N. | -52° 33' s.w.by w. | | | | | | | | | N. | -52° 03' s.w.by w. | | | | | | | | | S. | -52° 25' s.w.by w. | | | | | | | | | Direct. N. | -52° 48' s.w.by w. | | | | | | | | | N. | -51° 54' s.w.by w. | | | | | | | | | S. | -52° 05' s.w.by w. | | | | | | | | | N.S. | -52° 08' s.w.by w. | | | | | | | | | Direct. N. | -54° 58' n.w.by w. | | | | | | | | | N. | -53° 48' n.w.by w. | | | | | | | | | S. | -54° 03' n.w.by w. | | | | | | | | | N.S. | -53° 58' n.w.by w. | | | | | | | | | Direct. N. | -55° 33' s.w.by w.½ w.| | | | | | | | | N. | -54° 20' s.w.by w.½ w.| | | | | | | | | S. | -54° 58' s.w.by w.½ w.| | | | | | | | | N.S. | -55° 18' s.w.by w.½ w.| | | | | | | | | Direct. N. | -56° 18' s.w.by w. | | | | | | | | | N. | -55° 40' s.w.by w. | | | | | | | | | S. | -55° 52' s.w.by w. | | | | | | | | | N.S. | -56° 00' s.w.by w. | | | | | | | | | Direct. N. | -56° 38' s.s.w. | | | | | | | | | N. | -55° 40' s.s.w. | | | | | | | | | S. | -55° 48' s.s.w. | | | | | | | | | N.S. | -55° 50' s.s.w. | | | | | | | | | Direct. N. | -57° 18' s.w.by s. | | | | | | | | | N. | -56° 25' s.w.by s. | | | | | | | | | S. | -56° 35' s.w.by s. | | | | | | | | | N.S. | -56° 30' s.w.by s. | | | | | | | | | Direct. N. | -56° 43' s.by e. | | | | | | | | | N. | -56° 50' s.by e. | | | | | Up to the 13th of January the deflectors were set at minimum dip; on and after the 14th they were at the dip, so that the above observations gave dip and intensity. Very unsteady. Much motion. Much motion. Much motion. A calm, very unsteady. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Jan. 22 | -48° 35' | 10° 51' | Direct. | -57° 23 | s.w. by s. | +15 | -56° 44 | Table steady. | | | | | N. | -57° 17 | s.w. by s. | | | | | | | | S. | -57° 03 | s.w. by s. | | | | | | | | N.S. | -57° 05 | s.w. by s. | | | | | 23 | -50° 30' | 10° 25' | Direct. | -57° 33 | s.w. ½ s. | +15 | -57° 02 | Table steady. | | | | | N. | -57° 33 | s.w. ½ s. | | | | | | | | S. | -57° 45 | s.w. ½ s. | | | | | | | | N.S. | -57° 10 | s.w. ½ s. | | | | | 24 | -51° 48' | 9° 33' | Direct. | -58° 13 | s.w. by w. | +25 | -57° 13 | 1 p.m. table steady. | | | | | N. | -57° 55 | s.w. by w. | | | | | | | | S. | -57° 37 | s.w. by w. | | | | | | | | N.S. | -57° 40 | s.w. by w. | | | | | 25 | -52° 53' | 7° 53' | Direct. | -58° 13 | s.w. by w. | +25 | -57° 03 | Table rather unsteady. | | | | | N. | -57° 20 | s.w. by w. | | | | | | | | S. | -57° 40 | s.w. by w. | | | | | | | | N.S. | -57° 30 | s.w. by w. | | | | | 26 | -53° 52' | 6° 07' | Direct. | -58° 23 | w. by s. | +46 | -57° 01 | Table very steady. | | | | | N. | -57° 55 | w. by s. | | | | | | | | S. | -57° 40 | w. by s. | | | | | | | | N.S. | -58° 03 | w. by s. | | | | | 27 | -55° 08' | 5° 50' | Direct. | -58° 38 | s.s.w. ½ w.| +16 | -57° 26 | Table very unsteady. | | | | | N. | -57° 28 | s.s.w. ½ w.| | | | | | | | S. | -57° 25 | s.s.w. ½ w.| | | | | | | | N.S. | -58° 10 | s.s.w. ½ w.| | | | | 30 | -60° 43' | 4° 00' | Direct. | -61° 23 | s. | -08 | -61° 06 | Table unsteady. | | | | | N. | -61° 03 | s.e. by e. | +22 | -60° 14 | | | | | | S. | -60° 58 | s.e. by e. | | | | | | | | N.S. | -60° 08 | n. | +85 | -58° 35 | | | | | | N.S. | -60° 40 | n. | | | | | 31 | -61° 05' | 9° 03' | Direct. | -61° 32 | s.e. by s. | 00 | -61° 01 | Table steady. | | | | | N. | -61° 35 | s.e. by s. | | | | | | | | S. | -61° 13 | s.e. by s. | | | | | | | | N.S. | -60° 35 | s.e. by s. | | | | | Feb. 2 | -61° 54' | 16° 23' | Direct. | -64° 18 | E.S.E. | +30 | -63° 00 | Table unsteady. | | | | | N. | -63° 30 | E.S.E. | | | | | | | | S. | -63° 30 | E.S.E. | | | | | | | | N.S. | -63° 33 | E.S.E. | | | | | 3 | -61° 50' | 19° 13' | Direct. | -65° 13 | E.S.E. | +25 | -63° 55 | Table very steady. | | | | | N. | -64° 18 | E.S.E. | | | | | | | | S. | -64° 28 | E.S.E. | | | | | | | | N.S. | -64° 13 | E.S.E. | | | | | 4 | -62° 00' | 20° 25' | Direct. | -65° 33 | S.S.E. | -15 | -64° 55 | Table very steady. | | | | | N. | -64° 43 | S.S.E. | | | | | | | | S. | -64° 35 | S.S.E. | | | | | | | | N.S. | -64° 40 | S.S.E. | | | | | 6 | -64° 20' | 24° 05' | Direct. | -67° 03 | S.S.E. | -18 | -66° 37 | Table very steady. | | | | | N. | -66° 13 | S.S.E. | | | | | | | | S. | -66° 20 | S.S.E. | | | | | | | | N.S. | -66° 30 | S.S.E. | | | | | 7 | -65° 34' | 28° 30' | Direct. | -67° 18 | S.S.E. ½ E.| -16 | -66° 59 | Table very steady. | | | | | N. | -67° 00 | S.S.E. ½ E.| | | | | | | | S. | -66° 40 | S.S.E. ½ E.| | | | | | | | N.S. | -66° 45 | S.S.E. ½ E.| | | | | 9 | -66° 30' | 36° 46' | Direct. | -69° 13 | E. | +40 | -68° 16 | Table very steady. | | | | | N. | -69° 10 | E. | | | | | | | | S. | -69° 03 | E. | | | | | | | | N.S. | -69° 08 | E. | | | | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Feb. 10 | -66° 43' | 38° 49' | Direct. | -69° 28' | S.S.W. | -26 + 13 | -69° 22' | Table very steady. | | | | | N. | -69° 08' | S.S.W. | | | | | | | | S. | -69° 03' | S.S.W. | | | | | | | | N.S. | -68° 58' | S.S.W. | | | | | | | | Direct. | -71° 28' | N.E. | +89 + 13 | -69° 49' | Table very steady 8 p.m. | | | | | N. | -71° 43' | N.E. | | | | | | | | S. | -71° 23' | N.E. | | | | | | | | Direct. | -70° 08' | S.S.E. | -30 + 13 | -70° 12' | Table very unsteady. | | | | | N. | -70° 10' | S.S.E. | | | | | | | | S. | -69° 45' | S.S.E. | | | | | | | | N.S. | -69° 35' | S.S.E. | | | | | | | | Direct. | -70° 43' | E.N.E. | +66 + 13 | -69° 39' | Table steady. | | | | | N. | -71° 10' | E.N.E. | | | | | | | | S. | -71° 28' | E.N.E. | | | | | | | | N.S. | -70° 30' | E.N.E. | | | | | | | | Direct. | -68° 32' | N.N.E. | +85 + 32 | -66° 35' | Table very unsteady, ship pitching much. | | | | | Direct. | -68° 53' | S. ½ E. | -26 + 13 | -68° 40' | | | | | | N. | -68° 08' | S. ½ E. | | | | | | | | S. | -68° 20' | S. ¾ E. | | | | | | | | Direct. | -70° 08' | N. by W. | +80 + 13 | -68° 44' | Table very unsteady, heavy swell. | | | | | N. | -70° 32' | N. by W. | | | | | | | | S. | -70° 25' | N. by W. | | | | | | | | N.S. | -70° 02' | N. by W. | | | | | | | | Direct. | -68° 13' | S. by E. | -29 + 13 | -68° 40' | Table very unsteady. | | | | | N. | -68° 25' | S. by E. | | | | | | | | S. | -68° 35' | S. by E. | | | | | | | | Direct. | -70° 33' | E. by S. | +28 + 13 | -69° 36' | Table very unsteady 6 p.m. | | | | | N. | -70° 03' | E. by S. | | | | | | | | S. | -70° 20' | E. by S. | | | | | | | | N.S. | -70° 13' | E. by S. | | | | | | | | Direct. | -70° 53' | S.E. by E. ½ E. | +13 + 21 | -70° 03' | Table very unsteady. | | | | | S. | -70° 25' | S.E. by E. ½ E. | | | | | | | | N.S. | -70° 33' | S.E. by E. ½ E. | | | | | | | | Direct. | -70° 03' | S.S.E. | -28 + 13 | -70° 02' | Table unsteady. | | | | | N. | -70° 18' | S.S.E. | | | | | | | | S. | -69° 35' | S.S.E. | | | | | | | | N.S. | -69° 10' | S.S.E. | | | | | | | | Direct. | -69° 48' | E. | +41 + 24 | -68° 39' | Taken at 10 A.M., table very unsteady, ship pitching violently. Taken at 5 P.M. | | | | | N.S. | -69° 40' | E. | | | | | | | | Direct. | -70° 28' | E. | +41 + 13 | -69° 46' | | | | | | N. | -70° 13' | E. | | | | | | | | S. | -71° 20' | E. | | | | | | | | Direct. | -71° 28' | E.S.E. | +12 + 13 | -70° 46' | Table unsteady. | | | | | N. | -71° 18' | E.S.E. | | | | | | | | S. | -71° 00' | E.S.E. | | | | | | | | N.S. | -70° 58' | E.S.E. | | | | | | | | Direct. | -72° 13' | S.E. ½ E. | -11 + 13 | -72° 01' | Table unsteady. | | | | | N. | -72° 43' | S.E. ½ E. | | | | | | | | S. | -71° 48' | S.E. ½ E. | | | | | | | | N.S. | -71° 28' | S.E. ½ E. | | | | | | | | Direct. | -73° 28' | S.E. ½ S. | -21 + 13 | -73° 27' | Table steady. | | | | | N. | -73° 15' | S.E. ½ S. | | | | | | | | S. | -73° 38' | S.E. ½ S. | | | | | | | | N.S. | -72° 55' | S.E. ½ S. | | | | | | | | Direct. | -73° 43' | S.S.E. | -38 + 13 | -74° 02' | Table unsteady, heavy swell. | * Error, probably in the degree noted; result not included in the mean. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | 1845 Mar. 1. | -62° 10' | 72° 25' | Direct. | -74° 13' | S.S.E. | -38 +13 | -74° 35 | Table steady. | | | | | N. | -74° 23' | S.S.E. | | | | | | | | S. | -74° 20' | S.S.E. | | | | | | | | N.S. | -73° 43' | S.S.E. | | | | | | | | Direct. | -74° 28' | S. | -46 +13 | -74° 50 | Table very steady. | | | | | N. | -74° 13' | S. | | | | | | | | S. | -74° 23' | S. | | | | | | | | N.S. | -74° 03' | S. | | | | | 3. -64° 20' | 79° 38' | | Direct. | -75° 53' s.by w. ½ w. | | | | Table unsteady. | | | | | N. | -76° 45' s.by w. ½ w. | | | | | | | | | S. | -76° 27' s.by w. ½ w. | | | | | | | | | N.S. | -75° 10' s.by w. ½ w. | | | | | | 5. -61° 38' | 84° 40' | | Direct. | -76° 13' s.E. | | -23 +13 | -76° 27 | Table unsteady. | | | | | N. | -76° 10' s.E. | | | | | | | | | S. | -76° 38' s.E. | | | | | | | | | N.S. | -76° 08' s.E. | | | | | | 6. -60° 42' | 80° 12' | | Direct. | -77° 23' N.E. ½ N. | | +82 +13 | -75° 43 | Table unsteady. | | | | | N. | -77° 08' N.E. ½ N. | | | | | | | | | S. | -77° 23' N.E. ½ N. | | | | | | | | | N.S. | -77° 18' N.E. ½ N. | | | | | | 7. -61° 20' | 91° 09' | | Direct. | -76° 28' s.by E. | | -49 +13 | -77° 23 | Table very unsteady, taken at 10 A.M. | | | | | N. | -77° 20' s.by E. | | | | Taken at 8 P.M. in consequence of the A.M. observations being unsatisfactory. The aurora was very brilliant all the previous and succeeding nights. | | | | | S. | -77° 18' s.by E. | | | | | | | | | N.S. | -76° 02' s.by E. | | | | | | | | | Direct. | -77° 18' s.w.by S. | | -35 +13 | -77° 46 | Table steady, light N.W. swell. | | | | | N. | -77° 28' s.w.by S. | | | | | | | | | S. | -77° 50' s.w.by S. | | | | | | | | | N.S. | -77° 00' s.w.by S. | | | | | | 8. -61° 14' | 92° 03' | | Direct. | -79° 03' E. | | +26 +13 | -78° 26 | Table steady. | | | | | N. | -79° 43' E. | | | | | | | | | S. | -79° 05' E. | | | | | | | | | N.S. | -78° 30' E. | | | | | | 9. -60° 35' | 92° 25' | | Direct. | -78° 13' E. | | +26 +13 | -77° 30 | Table unsteady. | | | | | N. | -78° 25' E. | | | | | | | | | S. | -78° 15' E. | | | | | | | | | N.S. | -77° 42' E. | | | | | | 10. -60° 03' | 95° 36' | | Direct. | -76° 27' S.E. ½ S. | | -37 +13 | -77° 35 | Table very unsteady. | | | | | N. | -77° 30' S.E. ½ S. | | | | | | | | | S. | -77° 35' S.E. ½ S. | | | | | | | | | N.S. | -80° 03' E. ½ S. | | | | | | 11. -59° 52' | 99° 30' | | Direct. | -80° 23' E. ½ S. | | +15 +13 | -79° 21 | Table very unsteady, taken at 10 A.M. | | | | | N. | -79° 25' E. ½ S. | | | | Table steady, taken at 6 P.M. | | | | | S. | -79° 23' E. ½ S. | | | | | | | | | N.S. | -80° 28' E. ½ N. | | | | | | | | | Direct. | -81° 05' E. ½ N. | | +30 +13 | -79° 51 | | | | | | N. | -80° 50' E. ½ N. | | | | | | | | | S. | -79° 53' E. ½ N. | | | | | | | | | N.S. | -79° 18' E. by S. | | +11 +14 | -78° 36 | Table very unsteady, taken at 6 P.M. | | | | | N.S. | -79° 03' E. by S. | | | | | | | | | Direct. | -78° 33' E. by S. | | +12 +13 | -78° 40 | Table very unsteady. | | | | | N. | -79° 38' E. by S. | | | | | | | | | S. | -79° 22' E. by S. | | | | | | | | | N.S. | -78° 48' E. by S. | | | | | | 15. -55° 52' | 103° 06' | | Direct. | -79° 18' E. by N. | | +39 +13 | -78° 56 | Table very unsteady. | | | | | N. | -80° 28' E. by N. | | | | | | | | | S. | -80° 03' E. by N. | | | | | | | | | N.S. | -79° 23' E. by N. | | | | | MDCCCXLVI. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Mar. 16 | -54° 48' | 106° 04' | Direct. | -79° 33' | N.E. | +78 | -78° 09' | Table very unsteady. | | | | | N. | -80° 03' | N.E. | +13 | | | | | | | S. | -79° 25' | N.E. | | | | | | | | N.S. | -79° 38' | N.E. | | | | | | | | Direct. | -78° 23' | S.E. | -30 | -79° 16' | Table very unsteady, ship pitching violently. | | | | | N. | -79° 38' | S.E. | +13 | -78° 49' | | | | | | S. | -78° 55' | S.E. | | | | | | | | Direct. | -78° 38' | E. | +24 | -78° 21' | | | | | | N. | -78° 58' | E. | +13 | | | | | | | S. | -79° 18' | E. | | | | | Mar. 17 | -54° 17' | 108° 05' | Direct. | -79° 28' | N.N.E. ½ E.| +82 | -77° 28' | Table very unsteady. | | | | | N. | -78° 55' | N.N.E. ½ E.| +13 | | | | | | | S. | -78° 48' | N.N.E. ½ E.| | | | | | | | N.S. | -79° 00' | N.N.E. ½ E.| | | | | Mar. 18 | -53° 00' | 110° 08' | Direct. | -78° 08' | N.N.E. ½ E.| +85 | -76° 41' | Table very unsteady, heavy swell. | | | | | N. | -78° 48' | N.N.E. ½ E.| +21 | | | | | | | S. | -78° 25' | N.N.E. ½ E.| | | | | | | | N.S. | -77° 38' | N.E. by N. | +82 | -76° 30' | Table unsteady, very heavy swell. | | | | | N. | -78° 38' | N.E. by N. | +13 | | | | | | | S. | -78° 30' | N.E. by N. | | | | | | | | N.S. | -77° 33' | N.E. by N. | | | | | Mar. 19 | -51° 20' | 111° 23' | Direct. | -76° 43' | E.N.E. | +58 | -75° 31' | Table steady, light swell. | | | | | N. | -77° 13' | E.N.E. | +13 | | | | | | | S. | -77° 03' | E.N.E. | | | | | | | | N.S. | -75° 48' | E.N.E. | | | | | Mar. 20 | -49° 01' | 111° 47' | Direct. | -73° 23' | N. ½ E. | +76 | -72° 45' | Table very unsteady, heavy swell from W. | | | | | N. | -75° 45' | N. ½ E. | +13 | | | | | | | S. | -74° 48' | N. ½ E. | | | | | | | | N.S. | -72° 58' | N. ½ E. | | | | | Mar. 21 | -47° 21' | 115° 15' | Direct. | -71° 33' | N. by w. | +80 | -70° 11' | Table unsteady, light swell. | | | | | N. | -71° 33' | N. by w. | +13 | | | | | | | S. | -72° 15' | N. by w. | | | | | | | | N.S. | -71° 33' | N. by w. | | | | | Mar. 22 | -38° 52' | 116° 15' | Direct. | -70° 23' | N. by w. | +80 | -68° 49' | Table steady. | | | | | N. | -70° 45' | N. by w. | +13 | | | | | | | S. | -70° 50' | N. by w. | | | | | | | | N.S. | -69° 28' | N. by w. | | | | | Mar. 23 | -37° 03' | 116° 57' | Direct. | -68° 33' | N. by E. | +83 | -66° 46' | Table very steady, nearly calm. | | | | | N. | -68° 48' | N. by E. | +13 | | | | | | | S. | -68° 13' | N. by E. | | | | | | | | N.S. | -67° 53' | N. by E. | | | | | Mar. 24 | -36° 12' | -116° 50' | Direct. | -67° 30' | N.N.E. | +84 | -65° 28' | Table unsteady. | | | | | N. | -67° 13' | N.N.E. | +13 | | | | | | | S. | -66° 55' | N.N.E. | | | | | | | | N.S. | -66° 43' | N.N.E. | | | | | Mar. 25 | -35° 18' | 117° 07' | Direct. | -67° 28' | N.E. ½ E. | +86 | -65° 48' | Table unsteady. | | | | | N. | -68° 00' | N.E. ½ E. | +13 | | | | | | | S. | -67° 48' | N.E. ½ E. | | | | | | | | N.S. | -66° 30' | N.E. ½ E. | | | | | April 7 | -35° 02' | 117° 56' | Direct. | -65° 28' | Observed | +13 | -65° 11' | The observations were made at the same place that was used by Captains Flinders and Fitzroy. | | | | | N. | -65° 36' | on shore. | | | | | | | | S. | -65° 30' | | | | | | | | | N.S. | -65° 03' | | | | | | | | | Direct. | -65° 28' | Observed | +13 | -65° 11' | | | | | | N. | -65° 28' | on shore. | | | | | | | | S. | -65° 31' | | | | | | | | | N.S. | -65° 09' | | | | | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed. | Observed Inclination. | Ship's head. | Corrections. | Corrected Inclination. | Remarks. | |------------|------|-------|------------------|-----------------------|--------------|--------------|------------------------|----------| | **1845.** | | | | | | | | | | April 19. | | | Direct. | -65° 0' | S.S.W. | -16 | +24 | -64° 46 | | | | | | N.S. | -64° 46 | S.S.W. | | | -64° 46 | | | | | | Direct. | -65° 49 | S.W. | +01 | +24 | -65° 12 | | | | | | N.S. | -65° 25 | S.W. | | | -65° 12 | | | | | | Direct. | -65° 54 | W.S.W. | +23 | +24 | -64° 57 | | | | | | N.S. | -65° 33 | W.S.W. | | | -64° 57 | | | | | | Direct. | -66° 02 | W. | +46 | +24 | -64° 41 | | | | | | N.S. | -65° 39 | W. | | | -64° 41 | | | | | | Direct. | -66° 23 | W.N.W. | +70 | +24 | -64° 39 | | | | | | N.S. | -66° 03 | W.N.W. | | | -64° 39 | | | | | | Direct. | -66° 35 | N.W. | +92 | +24 | -64° 30 | | | | | | N.S. | -66° 16 | N.W. | | | -64° 30 | | | | | | Direct. | -66° 50 | N.N.W. | +84 | +24 | -64° 52 | | | | | | N.S. | -66° 29 | N.N.W. | | | -64° 52 | | | | | | Direct. | -66° 29 | N. | +84 | +24 | -64° 34 | | | | | | N.S. | -66° 14 | N. | | | -64° 34 | | | | | | Direct. | -66° 48 | N.N.E. | +83 | +24 | -64° 50 | | | | | | N.S. | -66° 26 | N.N.E. | | | -64° 50 | | | | | | Direct. | -66° 35 | N.E. | +92 | +24 | -64° 26 | | | | | | N.S. | -66° 09 | N.E. | | | -64° 26 | | | | | | Direct. | -66° 27 | E.N.E. | +70 | +24 | -64° 40 | | | | | | N.S. | -66° 00 | E.N.E. | | | -64° 40 | | | | | | Direct. | -66° 37 | E. | +46 | +24 | -65° 19 | | | | | | N.S. | -66° 21 | E. | | | -65° 19 | | | | | | Direct. | -66° 16 | E.S.E. | +23 | +24 | -65° 11 | | | | | | N.S. | -65° 40 | E.S.E. | | | -65° 11 | | | | | | Direct. | -65° 52 | S.E. | +01 | +24 | -65° 11 | | | | | | N.S. | -65° 19 | S.E. | | | -65° 11 | | | | | | Direct. | -65° 13 | S.S.E. | -16 | +24 | -64° 58 | | | | | | N.S. | -64° 58 | S.S.E. | | | -64° 58 | | | | | | Direct. | -65° 11 | S. | -21 | +24 | -64° 57 | | | | | | N.S. | -64° 46 | S. | | | -64° 57 | | | | | | Direct. | -66° 53 | N.W. | +92 | +13 | -65° 28 | Table unsteady. | | | | | N. | -67° 45 | N.W. | | | -65° 28 | Table unsteady. | | | | | S. | -67° 40 | N.W. | | | -65° 28 | Table unsteady. | | | | | N.S. | -66° 33 | N.W. | | | -65° 28 | Table unsteady. | | | | | Direct. | -66° 33 | N.W. by N. | +88 | +13 | -64° 44 | Table unsteady. | | | | | N. | -66° 28 | N.W. by N. | | | -64° 44 | Table unsteady. | | | | | S. | -66° 25 | N.W. by N. | | | -64° 44 | Table unsteady. | | | | | N.S. | -66° 15 | N.W. by N. | | | -64° 44 | Table unsteady. | | | | | Direct. | -63° 48 | N.W. by N. | +88 | +13 | -62° 14 | Table unsteady. | | | | | N. | -64° 25 | N.W. by N. | | | -62° 14 | Table unsteady. | | | | | S. | -63° 55 | N.W. by N. | | | -62° 14 | Table unsteady. | | | | | N.S. | -63° 33 | N.W. by N. | | | -62° 14 | Table unsteady. | | | | | Direct. | -60° 58 | W.N.W. | +72 | +13 | -59° 19 | Table steady. | | | | | N. | -61° 05 | W.N.W. | | | -59° 19 | Table steady. | | | | | S. | -60° 20 | W.N.W. | | | -59° 19 | Table steady. | | | | | N.S. | -60° 33 | W.N.W. | | | -59° 19 | Table steady. | | | | | Direct. | -58° 28 | N.by W.½ W. | +76 | +13 | -57° 17 | Table very unsteady, heavy swell. | | | | | N. | -58° 10 | N.by W.½ W. | | | -57° 17 | Table very unsteady, heavy swell. | | | | | S. | -58° 25 | N.by W.½ W. | | | -57° 17 | Table very unsteady, very heavy swell. | | | | | N.S. | -60° 00 | N.by W.½ W. | | | -55° 09 | Table very unsteady, very heavy swell. | The table was very steady during these observations. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | | | | | | | | | | | 1845 May 1 | -24° 00' | 99° 23' | Direct. N. S. N.S. | -55° 18' -55° 55' -56° 13' -54° 43' | W. W. W. W. | +51 +51 +56 +87 | -54° 28' -54° 03' -54° 16' -52° 49' | Table very unsteady, considerable motion. | | | | | | | | | | | | 2 | -24° 01' | 97° 30' | Direct. N. S. N.S. | -55° 03' -55° 20' -55° 28' -54° 35' | W. W. W. W. | +51 +51 +56 +87 | -54° 03' -54° 16' -54° 17' -52° 17' | Table steady. | | | | | | | | | | | | 3 | -24° 00' | 96° 06' | Direct. N. S. N.S. | -55° 18' -55° 13' -55° 30' -55° 38' | W.½ N. W.½ N. W.½ N. W.½ N. | +56 +56 +56 +87 | -54° 16' -54° 16' -54° 16' -52° 49' | Table steady. | | | | | | | | | | | | 6 | -22° 47' | 91° 00' | Direct. N. S. N.S. | -54° 28' -54° 40' -54° 28' -54° 18' | N.W. N.W. N.W. N.W. | +87 +87 +87 +87 | -52° 49' -52° 49' -52° 49' -52° 49' | Table very unsteady, heavy swell from W. | | | | | | | | | | | | 7 | -21° 50' | 89° 44' | Direct. N. S. N.S. | -53° 28' -53° 53' -54° 08' -54° 13' | N.W. N.W. N.W. N.W. | +86 +86 +86 +86 | -52° 17' -52° 17' -52° 17' -52° 17' | Table very unsteady, heavy W. swell. | | | | | | | | | | | | 8 | -20° 46' | 87° 59' | Direct. N. S. N.S. | -52° 28' -53° 03' -52° 58' -52° 13' | N.W. by w. N.W. by w. N.W. by w. N.W. by w. | +82 +82 +82 +82 | -51° 06' -51° 06' -51° 06' -51° 06' | Table steady. Observer Mr. Burdon, R.N. | | | | | | | | | | | | 9 | -20° 38' | 85° 26' | Direct. N. S. N.S. | -52° 03' -52° 35' -52° 15' -52° 38' | W.½ N. W.½ N. W.½ N. W.½ N. | +56 +56 +56 +56 | -51° 14' -51° 14' -51° 14' -51° 14' | Table steady. | | | | | | | | | | | | 10 | -20° 26' | 82° 22' | Direct. N. S. N.S. | -52° 43' -53° 00' -52° 58' -52° 33' | W.½ N. W.½ N. W.½ N. W.½ N. | +56 +56 +56 +56 | -51° 40' -51° 40' -51° 40' -51° 40' | Table very unsteady, heavy swell. | | | | | | | | | | | | 11 | -20° 36' | 79° 22' | Direct. N. S. N.S. | -52° 49' -52° 47' -52° 25' -52° 50' | W.½ N. W.½ N. W.½ N. W.½ N. | +53 +53 +53 +53 | -51° 37' -51° 37' -51° 37' -51° 37' | Table very unsteady. Observer Mr. Burdon, R.N. | | | | | | | | | | | | 12 | -20° 44' | 78° 31' | Direct. N. S. N.S. | -54° 08' -53° 55' -53° 38' -53° 23' | W. W.N.W. W.N.W. W.N.W. W.N.W. | +51 +72 +86 +68 | -52° 47' -51° 55' -51° 37' -51° 20' | Table very unsteady. Observer Mr. Burdon, R.N. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | | | | | | | Ship's attraction | Index | | | | 1845. | | | | | | +68 | +24 | -51 54 | -52 03 | | May 12. | -20° 44′ | 78° 31′ | Direct. | -53° 48′ | N.N.E. | +15 | +24 | -52 01 | | | | | | N.S. | -53 03 | N.N.E. | +19 | +24 | -52 46 | | | | | | Direct. | -52° 48′ | S. | +30 | +24 | -52 29 | | | | | | N.S. | -52 33 | S. | +44 | +24 | -52 35 | | | | | | Direct. | -53° 48′ | S.S.W. | +51 | +24 | -52 42 | | | | | | N.S. | -53 10 | S.S.W. | +86 | +24 | -51 30 | | | | | | Direct. | -53° 43′ | S.W. | +70 | +24 | -51 18 | | | | | | N.S. | -53 03 | S.W. | +86 | +24 | -51 24 | | | | | | Direct. | -53° 48′ | W.S.W. | +51 | +24 | -52 27 | | | | | | N.S. | -53 38 | W.S.W. | +30 | +24 | -52 34 | | | | | | Direct. | -53° 48′ | W. | +56 | +13 | -52 13 | | | | | | N.S. | -54 05 | W. | +56 | +13 | -52 20 | | | | | | Direct. | -53° 28′ | N.W. | +53 | +13 | -52 51 | | | | | | N.S. | -53 13 | N.W. | +44 | +13 | -53 10 | | | | | | Direct. | -52° 58′ | N. | +77 | +13 | -52 54 | | | | | | N.S. | -52 45 | N. | +77 | +13 | -53 10 | | | | | | Direct. | -53° 23′ | N.E. | +53 | +13 | -52 46 | | | | | | N.S. | -53 05 | N.E. | +53 | +13 | -52 51 | | | | | | Direct. | -53° 53′ | E. | +53 | +13 | -52 51 | | | | | | N.S. | -53 30 | E. | +53 | +13 | -52 51 | | | | | | Direct. | -53° 48′ | S.E. | +53 | +13 | -52 51 | | | | | | N.S. | -53 08 | S.E. | +53 | +13 | -52 51 | | | | | | Direct. | -53° 08′ | W. ½ N. | +53 | +13 | -52 51 | | | | | | N. | -53 00 | W. ½ N. | +53 | +13 | -52 51 | | | | | | S. | -53 35 | W. ½ N. | +53 | +13 | -52 51 | | | | | | N.S. | -53 43 | W. ½ N. | +53 | +13 | -52 51 | | | | | | Direct. | -53° 38′ | W. ½ N. | +53 | +13 | -52 51 | | | | | | N. | -53 48 | W. ½ N. | +53 | +13 | -52 51 | | | | | | S. | -53 50 | W. ½ N. | +53 | +13 | -52 51 | | | | | | N.S. | -53 08 | W. ½ N. | +53 | +13 | -52 51 | | | | | | Direct. | -54° 08′ | W. ¼ N. | +53 | +13 | -52 51 | | | | | | N. | -54 48 | W. ¼ N. | +53 | +13 | -52 51 | | | | | | S. | -53 53 | W. ¼ N. | +53 | +13 | -52 51 | | | | | | N.S. | -53 58 | W. ¼ N. | +53 | +13 | -52 51 | | | | | | Direct. | -54° 43′ | W.S.W. | +53 | +13 | -52 51 | | | | | | N. | -54 45 | W.S.W. | +53 | +13 | -52 51 | | | | | | S. | -54 05 | W.S.W. | +53 | +13 | -52 51 | | | | | | N.S. | -53 53 | W.S.W. | +53 | +13 | -52 51 | | | | | | Direct. | -54° 28′ | N.W. by N. | +53 | +13 | -52 51 | | | | | | N. | -54 35 | N.W. by N. | +53 | +13 | -52 51 | | | | | | S. | -54 23 | N.W. by N. | +53 | +13 | -52 51 | | | | | | N.S. | -54 08 | N.W. by N. | +53 | +13 | -52 51 | | | | | | Direct. | -54° 53′ | N.W. by N. | +53 | +13 | -52 51 | | | | | | N. | -54 45 | N.W. by N. | +53 | +13 | -52 51 | | | | | | S. | -54 38 | N.W. by N. | +53 | +13 | -52 51 | | | | | | N.S. | -54 23 | N.W. by N. | +53 | +13 | -52 51 | | | | | | Direct. | -55° 03′ | W. by N. | +53 | +13 | -52 51 | | | | | | N. | -54 58 | W. by N. | +53 | +13 | -52 51 | | | | | | S. | -55 08 | W. by N. | +53 | +13 | -52 51 | | | | | | N.S. | -54 58 | W. by N. | +53 | +13 | -52 51 | | | | | | Direct. | -54° 58′ | W. by N. | +53 | +13 | -52 51 | | | | | | N. | -54 45 | W. by N. | +53 | +13 | -52 51 | | | | | | S. | -55 00 | W. by N. | +53 | +13 | -52 51 | | | | | | N.S. | -54 28 | W. by N. | +53 | +13 | -52 51 | | To obtain corrections for the ship's attraction. Calm, table very unsteady, considerable rolling motion. Table very unsteady. Observer Mr. Burdon, R.N. Table steady. Table very unsteady. Observer Mr. Burdon, R.N. Table steady, nearly calm. Table steady, Observer Mr. Burdon, R.N. Table steady. Table steady, Observer Mr. Burdon, R.N. ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |----------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | | | | | | | | | | | 1845. | | | | | | | | | | May 21. | −21° 02′ | 66° 02′ | Direct. | −55° 28′ | w. by n. | +63 | −54° 03′ | Table steady. | | | | | N. | −55° 13′ | w. by n. | | | | | | | | S. | −55° 23′ | w. by n. | | | | | | | | N.S. | −55° 13′ | w. by n. | | | | | | | | Direct. | −55° 28′ | w. by n. | | | | | | | | N. | −55° 00′ | w. by n. | +63 | −53° 59′ | Table very unsteady. | | | | | S. | −55° 23′ | w. by n. | | | | | | | | N.S. | −55° 07′ | w. by n. | | | | | | | | Direct. | −54° 27′ | | | | | | | | | N. | −54° 22′ | | | | | | | | | S. | −54° 59′ | | | | | | | | | N.S. | −54° 01′ | | | | | | | | | Port Louis, | Observed | | | | | | | | | Mauritius. | on shore. | | | | | | | | | | | | | | | | | | | Direct. | −55° 33′ | | | | | | | | | N. | −55° 20′ | | | | | | | | | S. | −55° 28′ | | | | | | | | | N.S. | −55° 35′ | | | | | | | | | Direct. | −60° 33′ | | | | | | | | | N. | −59° 50′ | | | | | | | | | S. | −60° 05′ | | | | | | | | | N.S. | −60° 10′ | | | | | | | | | Direct. | −59° 48′ | | | | | | | | | N. | −59° 18′ | | | | | | | | | S. | −59° 48′ | | | | | | | | | N.S. | −59° 58′ | | | | | | | | | Direct. | −59° 43′ | | | | | | | | | N. | −59° 53′ | | | | | | | | | S. | −60° 18′ | | | | | | | | | N.S. | −59° 48′ | | | | | | | | | Direct. | −60° 33′ | | | | | | | | | N. | −60° 25′ | | | | | | | | | S. | −60° 23′ | | | | | | | | | N.S. | −60° 23′ | | | | | | | | | Direct. | −59° 58′ | | | | | | | | | N. | −59° 56′ | | | | | | | | | S. | −60° 28′ | | | | | | | | | N.S. | −59° 50′ | | | | | | | | | Direct. | −60° 38′ | | | | | | | | | N. | −59° 45′ | | | | | | | | | S. | −60° 25′ | | | | | | | | | N.S. | −60° 02′ | | | | | | | | | Direct. | −59° 03′ | | | | | | | | | N. | −58° 30′ | | | | | | | | | S. | −58° 43′ | | | | | | | | | N.S. | −58° 38′ | | | | | | | | | Direct. | −58° 33′ | | | | | | | | | N. | −58° 20′ | | | | | | | | | S. | −58° 35′ | | | | | | | | | N.S. | −58° 05′ | | | | | | | | | Direct. | −58° 38′ | | | | | | | | | N. | −58° 25′ | | | | | | | | | S. | −59° 08′ | | | | | | | | | N.S. | −58° 20′ | | | | | | | | | Direct. | −58° 23′ | | | | | | | | | N. | −58° 08′ | | | | | | | | | S. | −58° 45′ | | | | | | | | | N.S. | −57° 45′ | | | | | | June 2. | −26° 25′ | 49° 12′ | Direct. | −58° 36′ | | | | | | | | | N. | −58° 52′ | | | | | | | | | S. | −58° 44′ | | | | | | | | | N.S. | −58° 52′ | | | | | | | | | Direct. | −58° 54′ | | | | | | | | | N. | −59° 08′ | | | | | | | | | S. | −59° 08′ | | | | | | | | | N.S. | −59° 08′ | | | | | | | | | Direct. | −57° 19′ | | | | | | | | | N. | −57° 28′ | | | | | | | | | S. | −57° 34′ | | | | | | | | | N.S. | −57° 06′ | | | | | | | | | Direct. | −57° 06′ | | | | | | | | | N. | −57° 06′ | | | | | | | | | S. | −57° 06′ | | | | | | | | | N.S. | −57° 06′ | | | | | ## Observations of Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |------------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | **1835.** | | | | | | | | | | June 16. | −35°46′| 23°35′| Direct. | −57°38′ | w. by N. | +63 | +13 | −56°08 | Table steady, fresh breeze. | | | | | N. | −57°23′ | w. by N. | | | | | | | | S. | −57°15′ | w. by N. | | | | | | | | N.S. | −57°20′ | w. by N. | | | | | | | | Direct. | −56°48′ | w. by N. | +72 | +13 | −55°18 | Table steady. | | | | | N. | −56°43′ | w. by N. | | | | | | | | S. | −56°40′ | w. by N. | | | | | | | | N.S. | −56°40′ | w. by N. | | | | | | | | Direct. | −56°18′ | w. by s. | +46 | +13 | +55°08 | Table steady. | | | | | N. | −55°45′ | w. by s. | | | | | | | | S. | −56°08′ | w. by s. | | | | | | | | N.S. | −56°18′ | w. by s. | | | | | | | | Direct. | −54°17′ | Observed on shore. | +24 | −53°37 | −53°37 | Observed in the dockyard at Simon's Bay. | | | | | N.S. | −53°45′ | | | | | | | | | Direct. | −54°12′ | | | | | | | | | N. | −53°13′ | Observed on shore. | +13 | −53°32 | −53°32 | Monthly mean dip by Robinson's needles | | | | | S. | −53°46′ | | | | | | | | | N.S. | −53°51′ | | | | | | | | | Direct. | −54°08′ | Observed on shore. | +13 | −53°30 | −53°30 | A1 53°24 | | | | | N. | −53°15′ | | | | | | | | | S. | −53°46′ | | | | | | | | | N.S. | −53°44′ | | | | | | July 2. | | | Magnetic Observatory, Cape of Good Hope. | | | | | | | | | | Direct. | −53°59′ | s. | +09 | +24 | −53°20 | A2 53°24 | | | | | N.S. | −53°46′ | s. | | | | | | | | Direct. | −53°50′ | s.s.w. | +14 | +24 | −52°56 | Mean 53°24 | | | | | N.S. | −53°17′ | s.s.w. | | | | | | | | Direct. | −54°25′ | s.w. | +26 | +24 | −53°20 | | | | | | N.S. | −53°54′ | s.w. | | | | | | | | Direct. | −55°04′ | w.s.w. | +41 | +24 | −53°50 | | | | | | N.S. | −54°46′ | w.s.w. | | | | | | | | Direct. | −55°18′ | w. | +51 | +24 | −53°54 | | | | | | N.S. | −55°01′ | w. | | | | | | | | Direct. | −55°34′ | w.n.w. | +72 | +24 | −53°36 | | | | | | N.S. | −54°49′ | w.n.w. | | | | | | | | Direct. | −55°30′ | n.w. | +88 | +24 | −53°28 | | | | | | N.S. | −55°10′ | n.w. | | | | | | | | Direct. | −55°07′ | n.n.w. | +71 | +24 | −53°25 | | | | | | N.S. | −54°52′ | n.n.w. | | | | | | | | Direct. | −54°36′ | n. | +75 | +24 | −52°46 | | | | | | N.S. | −54°14′ | n. | | | | | | | | Direct. | −55°10′ | n.n.e. | +71 | +24 | −53°14 | | | | | | N.S. | −54°28′ | n.n.e. | | | | | | | | Direct. | −55°16′ | n.e. | +87 | +24 | −53°10 | | | | | | N.S. | −54°46′ | n.e. | | | | | | | | Direct. | −55°34′ | e.n.e. | +72 | +24 | −53°41 | | | | | | N.S. | −54°59′ | e.n.e. | | | | | | | | Direct. | −55°22′ | e. | +51 | +24 | −53°55 | | | | | | N.S. | −54°58′ | e. | | | | | | | | Direct. | −55°05′ | e.s.e. | +41 | +24 | −53°43 | | | | | | N.S. | −54°31′ | e.s.e. | | | | | | | | Direct. | −54°24′ | s.e. | +26 | +24 | −53°26 | | | | | | N.S. | −54°07′ | s.e. | | | | | | | | Direct. | −54°39′ | s.s.e. | +14 | +24 | −53°37 | | | | | | N.S. | −53°50′ | s.s.e. | | | | At anchor in Simon's Bay, Cape of Good Hope. To obtain corrections for the ship's attraction. Observations of the Magnetic Force made on board Her Majesty's hired Bark "Pagoda," from the 10th of January 1845 to the 20th of June 1845, with Needle A. of C. 9. one hour after Noon. Observer, Lieut. T. E. L. Moore, R.N. | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head. | Intensity | Corrections | Corrected intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|--------------|-----------|-------------|---------------------|---------| | 1845. | | | | | | | | | | | | Jan. 10. | -34° 46' | 17° 46' | Def. N. | 48° 19' | 64° | w. by n. | 0·988 | -0·008 | 0·980 | | | | | | Def. S. | 49° 15' | 64° | w. by n. | 0·975 | -0·008 | 0·967 | | | | | | Def. N.S. | 67° 36' | 64° | w. by n. | 0·988 | -0·008 | 0·979 | | | | | | Def. N. | 46° 11' | 64° | w. by n. | 1·001 | -0·008 | 0·993 | | | | | | Def. S. | 45° 42' | 64° | w. by n. | 1·014 | -0·008 | 1·006 | | | | | | Def. N. | 49° 23' | 68° | n.w. by w. | 0·960 | +0·002 | 0·962 | | | | | | Def. S. | 49° 22' | 68° | n.w. by w. | 0·973 | +0·002 | 0·975 | | | | | | Def. N.S. | 68° 57' | 68° | n.w. by w. | 0·956 | +0·002 | 0·958 | | | | | | Mag. N. | 47° 00' | 66° | n.w. by w. | 0·969 | +0·002 | 0·971 | | | | | | Mag. S. | 46° 54' | 66° | n.w. by w. | 0·966 | +0·002 | 0·968 | | | | | | wt. 1 gr. | 19° 56' | 66° | n.w. by w. | 0·922 | +0·002 | 0·924 | | | | | | wt. 2 grs. | 42° 14' | 66° | n.w. by w. | 0·978 | +0·002 | 0·980 | | | 12. | -35° 17' | 14° 00' | Def. N. | 49° 55' | 78° | w. s. | 0·950 | -0·016 | 0·934 | | | | | | Def. S. | 50° 42' | 78° | w. s. | 0·929 | -0·016 | 0·913 | | | | | | Def. N.S. | 69° 27' | 78° | w. s. | 0·944 | -0·016 | 0·928 | | | | | | Mag. N. | 48° 03' | 78° | w. s. | 0·930 | -0·016 | 0·914 | | | | | | Mag. S. | 47° 16' | 78° | w. s. | 0·952 | -0·016 | 0·936 | | | 13. | -35° 24' | 13° 23' | Mag. N. | 48° 59' | 72° | s.w. s. | 0·971 | -0·033 | 0·938 | | | | | | Mag. S. | 50° 00' | 72° | s.w. s. | 0·952 | -0·033 | 0·929 | | | | | | Mag. N.S. | 68° 30' | 72° | s.w. s. | 0·965 | -0·033 | 0·932 | | | | | | Mag. N. | 47° 13' | 72° | s.w. s. | 0·961 | -0·033 | 0·928 | | | | | | Mag. S. | 46° 58' | 72° | s.w. s. | 0·966 | -0·033 | 0·931 | | | | | | wt. 1 gr. | 19° 17' | 72° | s.w. s. | 0·952 | -0·033 | 0·929 | | | | | | wt. 1½ gr. | 30° 42' | 76° | s.w. s. | 0·981 | -0·033 | 0·958 | | | | | | wt. 2 grs. | 42° 46' | 76° | s.w. s. | 0·968 | -0·033 | 0·935 | | | 15. | -38° 42' | 14° 27' | Def. N. | 47° 18' | 64° | s.by w. s.w.| 1·019 | -0·038 | 0·981 | | | | | | Def. S. | 48° 25' | 64° | s.by w. s.w.| 1·005 | -0·038 | 0·967 | | | | | | Def. N.S. | 66° 52' | 64° | s.by w. s.w.| 1·006 | -0·038 | 0·970 | | | | | | Mag. N. | 45° 49' | 64° | s.by w. s.w.| 1·018 | -0·038 | 0·980 | | | | | | Mag. S. | 45° 21' | 64° | s.by w. s.w.| 1·031 | -0·038 | 0·993 | | | 16. | -39° 10' | 14° 38' | Def. N. | 48° 27' | 70° | s.w.byw.s.w.| 0·984 | -0·024 | 0·960 | | | | | | Def. S. | 48° 53' | 70° | s.w.byw.s.w.| 0·988 | -0·024 | 0·964 | | | | | | Def. N.S. | 67° 27' | 70° | s.w.byw.s.w.| 0·992 | -0·024 | 0·968 | | | | | | Mag. N. | 46° 37' | 70° | s.w.byw.s.w.| 0·985 | -0·024 | 0·961 | | | | | | Mag. S. | 46° 04' | 70° | s.w.byw.s.w.| 0·997 | -0·024 | 0·971 | | | | | | Mag. N.S. | 47° 52' | 68° | w.s.w. | 1·000 | -0·024 | 0·976 | | | | | | Mag. S. | 48° 16' | 68° | w.s.w. | 1·009 | -0·024 | 0·983 | | | | | | Mag. N.S. | 66° 22' | 68° | w.s.w. | 1·020 | -0·024 | 0·994 | | | 21. | -50° 21' | 10° 31' | Mag. N. | 45° 42' | 45° | s.w. | 1·074 | -0·032 | 1·042 | | | | | | Mag. S. | 46° 14' | 45° | s.w. | 1·076 | -0·032 | 1·044 | | | | | | Mag. N.S. | 63° 54' | 45° | s.w. | 1·086 | -0·032 | 1·058 | | | | | | Mag. N. | 44° 19' | 45° | s.w. | 1·082 | -0·032 | 1·051 | | | | | | Mag. S. | 44° 07' | 45° | s.w. | 1·090 | -0·032 | 1·059 | | | 23. | -50° 48' | 10° 18' | Mag. N. | 44° 45' | 43° | s.w.byw.s.w.| 1·110 | -0·024 | 1·086 | | | | | | Mag. S. | 44° 54' | 43° | s.w.byw.s.w.| 1·120 | -0·024 | 1·097 | | | | | | Mag. N.S. | 63° 39' | 43° | s.w.byw.s.w.| 1·125 | -0·024 | 1·100 | | | | | | Mag. N. | 43° 44' | 42° | s.w.byw.s.w.| 1·108 | -0·024 | 1·085 | | | | | | Mag. S. | 43° 43' | 42° | s.w.byw.s.w.| 1·112 | -0·024 | 1·089 | | | 24. | -51° 44' | 9° 36' | Mag. N. | 44° 15' | 49° | s.w. by w. | 1·128 | -0·024 | 1·105 | | | | | | Mag. N.S. | 62° 19' | 50° | s.w.byw.s.w.| 1·136 | -0·024 | 1·115 | | | | | | wt. 1 gr. | 17° 12' | 50° | s.w.byw.s.w.| 1·063 | -0·024 | 1·038* | | | | | | wt. 2 grs. | 35° 29' | 50° | s.w.byw.s.w.| 1·132 | -0·024 | 1·107 | | * Omitted in mean. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|---------------------|-------------|------------|-----------|--------------|---------------------|---------| | Jan. 25. | -53° | 21' | Def. N. | 43° | s.w.byw.½w. | 1·145 | -0·24 | +0·01 | 1·122 | Table steady; passing through streams of ice. | | | | | Def. S. | 43° | s.w.byw.½w. | 1·152 | -0·24 | +0·01 | 1·129 | | | | | | Def. N.S. | 61° | s.w.byw.½w. | 1·147 | -0·24 | +0·06 | 1·129 | | | | | | Mag. N. | 42° | s.w.byw.½w. | 1·159 | -0·24 | +0·02 | 1·137 | | | | | | Mag. S. | 42° | s.w.byw.½w. | 1·174 | -0·24 | +0·02 | 1·152 | | | | | | Def. N. | 43° | w. by n. | 1·148 | -0·12 | +0·01 | 1·137 | | | | | | Def. S. | 44° | w. by n. | 1·145 | -0·12 | +0·01 | 1·134 | | | | | | Def. N.S. | 62° | w. by n. | 1·142 | -0·12 | +0·06 | 1·136 | | | | | | Mag. N. | 43° | w. by n. | 1·142 | -0·12 | +0·02 | 1·132 | | | | | | Mag. S. | 42° | w. by n. | 1·164 | -0·12 | +0·02 | 1·154 | | | | | | wt. 1 gr. | 16° | w. by n. | 1·096 | -0·12 | +0·02 | 1·085* | | | | | | wt. 2 grs. | 34° | w. by n. | 1·164 | -0·12 | +0·02 | 1·154 | | | Feb. 1. | -62° | 06' | Def. N. | 42° | s.s.w.½w. | 1·184 | -0·42 | +0·01 | 1·143 | Ship pitching heavily, fresh breeze. | | | | | Def. S. | 39° | s.s.e. | 1·324 | -0·42 | +0·02 | 1·284 | | | | | | Def. N.S. | 57° | s.s.e. | 1·331 | -0·42 | +0·08 | 1·297 | | | | | | Mag. N. | 39° | s.s.e. | 1·310 | -0·42 | +0·03 | 1·271 | | | | | | Mag. S. | 39° | s.s.e. | 1·349 | -0·42 | +0·03 | 1·310 | | | | | | Def. N. | 38° | s.e. by s. | 1·398 | -0·40 | +0·02 | 1·360 | Much motion, table unsteady. | | | | | Def. S. | 38° | s.e. by s. | 1·376 | -0·40 | +0·02 | 1·338 | | | | | | Def. N.S. | 39° | s.e.½e. | 1·341 | -0·36 | +0·02 | 1·307 | | | | | | Mag. N. | 39° | s.e.½e. | 1·357 | -0·36 | +0·02 | 1·323 | Heavy snow, a head sea, ship pitching violently. | | | | | Mag. S. | 39° | s.e.½e. | 1·358 | -0·36 | +0·09 | 1·331 | | | | | | Def. N. | 38° | s.½e. | 1·339 | -0·36 | +0·03 | 1·306 | | | | | | Def. S. | 38° | s.½e. | 1·372 | -0·36 | +0·03 | 1·339 | | | | | | Def. N.S. | 38° | s.½e. | 1·391 | -0·51 | +0·01 | 1·341 | | | | | | Mag. N. | 38° | s.½e. | 1·395 | -0·51 | +0·01 | 1·345 | | | | | | Mag. S. | 38° | s.½e. | 1·376 | -0·51 | +0·08 | 1·333 | Water very clear from ice, a little motion. Vibration great. | | | | | wt. 1 gr. | 13° | s.½e. | 1·406 | -0·51 | +0·02 | 1·357 | | | | | | wt. 2 grs. | 27° | s.½e. | 1·353 | -0·51 | -0·02 | 1·300* | | | Feb. 5. | -63° | 19' | Def. N. | 38° | s.s.e. | 1·376 | -0·46 | +0·02 | 1·332 | A heavy swell from S.E., light breezes, table steady. | | | | | Def. S. | 38° | s.s.e. | 1·405 | -0·46 | +0·02 | 1·361 | | | | | | Def. N.S. | 55° | s.s.e. | 1·397 | -0·46 | +0·09 | 1·360 | | | | | | Mag. N. | 38° | s.s.e. | 1·396 | -0·46 | +0·03 | 1·353 | | | | | | Mag. S. | 38° | s.s.e. | 1·407 | -0·46 | +0·03 | 1·364 | | | | | | wt. 1 gr. | 13° | s.s.e. | 1·313 | -0·46 | -0·03 | 1·264* | | | | | | wt. 2 grs. | 26° | s.s.e. | 1·450 | -0·46 | -0·03 | 1·401 | | | Feb. 6. | -64° | 25' | Def. N. | 37° | s.s.e.½e. | 1·447 | -0·45 | +0·01 | 1·403 | | | | | | Def. S. | 37° | s.s.e.½e. | 1·436 | -0·45 | +0·01 | 1·392 | Water perfectly smooth, very steady. | | | | | Def. N.S. | 54° | s.s.e.½e. | 1·436 | -0·45 | +0·08 | 1·399 | | | | | | Mag. N. | 36° | s.by e.½e. | 1·487 | -0·51 | +0·01 | 1·437 | | | | | | Mag. S. | 37° | s.by e.½e. | 1·472 | -0·51 | +0·01 | 1·422 | | | | | | Def. N.S. | 37° | s.by e.½e. | 1·466 | -0·51 | +0·08 | 1·423 | | | | | | Mag. N. | 37° | s.by e.½e. | 1·499 | -0·51 | +0·02 | 1·450 | | | | | | Mag. S. | 37° | s.by e.½e. | 1·487 | -0·51 | +0·02 | 1·438 | | | | | | wt. 1 gr. | 13° | s.s.e. | 1·392 | -0·50 | -0·02 | 1·340* | | | | | | wt. 2 grs. | 26° | s.s.e. | 1·475 | -0·50 | -0·02 | 1·423 | | | Feb. 8. | -66° | 27' | Def. N. | 36° | s.e. by e. | 1·494 | -0·42 | +0·02 | 1·454 | | | | | | Def. S. | 36° | s.e. by e. | 1·483 | -0·42 | +0·02 | 1·443 | | | | | | Def. N.S. | 54° | s.e. by e. | 1·474 | -0·42 | +0·11 | 1·443 | | | | | | Mag. N. | 37° | s.e. by e. | 1·499 | -0·42 | +0·04 | 1·461 | | | | | | Mag. S. | 37° | s.e. by e. | 1·475 | -0·42 | +0·04 | 1·437 | | * Omitted in mean. MDCCCXLVI. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed. | Angle of deflection. | Temperature. | Ship's head. | Intensity. | Corrections. | Corrected Intensity. | Remarks. | |--------|------|-------|------------------|----------------------|--------------|--------------|------------|--------------|----------------------|----------| | Feb. 9 | -66°36'36"50" | Def. N. | 36°06'39" | s.e. by e. | 1·514 | -0·042 | +0·001 | 1·473 | Light breeze, very steady, water smooth. | | | | Def. S. | 36°43'39" | s.e. by e. | 1·508 | -0·042 | +0·001 | 1·467 | | | | | Def. N.S. | 53°41'36" | s.e. by e. | 1·505 | -0·042 | +0·010 | 1·473 | | | | | Mag. N. | 36°55'35" | s.e. by e. | 1·505 | -0·042 | +0·003 | 1·466 | | | | | Mag. S. | 36°59'34" | s.e. by e. | 1·509 | -0·042 | +0·003 | 1·470 | | | | | Def. N. | 35°39'34" | s. by w. | 1·540 | -0·050 | +0·002 | 1·492 | Steady, water very smooth. | | | | Def. S. | 36°31'34" | s. by w. | 1·509 | -0·050 | +0·002 | 1·461 | | | | | Def. N.S. | 52°45'34" | s. by w. | 1·549 | -0·050 | +0·009 | 1·508 | | | | | Mag. N. | 36°27'34" | s. by w. | 1·540 | -0·050 | +0·003 | 1·493 | | | | | Mag. S. | 37°02'34" | s. by w. | 1·509 | -0·050 | +0·003 | 1·462 | | | | | Def. N. | 36°10'35" | N.E. | 1·510 | -0·016 | +0·002 | 1·496 | Sailing along a pack of ice, unsteady. | | | | Def. S. | 35°30'32" | s.½ E. | 1·548 | -0·050 | +0·003 | 1·501 | | | | | Def. N.S. | 53°16'32" | s.½ E. | 1·533 | -0·050 | +0·003 | 1·486 | | | | | Mag. N. | 36°37'32" | s.½ E. | 1·520 | -0·050 | +0·013 | 1·483 | Fresh breeze, table unsteady. | | | | Mag. S. | 36°03'32" | s.½ E. | 1·575 | -0·050 | +0·004 | 1·529 | | | | | Def. N. | 36°00'34" | E.N.E. | 1·519 | -0·025 | +0·002 | 1·496 | | | | | Def. S. | 36°37'34" | E.N.E. | 1·504 | -0·025 | +0·002 | 1·481 | | | | | Def. N.S. | 53°29'33" | E.N.E. | 1·506 | -0·025 | +0·011 | 1·492 | Swell from E., table unsteady. | | | | Mag. N. | 36°43'33" | E.N.E. | 1·521 | -0·025 | +0·004 | 1·500 | | | | | Mag. S. | 37°06'33" | E.N.E. | 1·503 | -0·025 | +0·004 | 1·482 | | | | | Def. N. | 36°18'34" | N.E. by N. | 1·502 | -0·016 | +0·002 | 1·488 | Table unsteady, very squally. | | | | Def. S. | 36°24'34" | N.E. by N. | 1·515 | -0·016 | +0·002 | 1·501 | | | | | Def. N.S. | 53°59'41" | s. by e. | 1·520 | -0·050 | +0·001 | 1·471 | | | | | Def. S. | 36°56'41" | s. by e. | 1·487 | -0·050 | +0·001 | 1·438 | | | | | Def. N.S. | 53°48'41" | s. by e. | 1·490 | -0·050 | +0·008 | 1·448 | Thick weather, a heavy swell, unsteady. | | | | Mag. N. | 37°07'40" | s. by e. | 1·493 | -0·050 | +0·003 | 1·446 | | | | | Mag. S. | 37°15'40" | s. by e. | 1·492 | -0·050 | +0·003 | 1·445 | | | | | Def. N. | 36°34'36" | N. | 1·487 | -0·018 | +0·002 | 1·471 | | | | | Def. S. | 37°08'36" | N. | 1·475 | -0·018 | +0·002 | 1·459 | Calm, a heavy sea, not steady. | | | | Def. N.S. | 53°18'38" | N. | 1·518 | -0·018 | +0·010 | 1·510 | | | | | Mag. N. | 36°53'38" | N. | 1·505 | -0·018 | +0·003 | 1·490 | | | | | Mag. S. | 37°13'37" | N. | 1·495 | -0·018 | +0·003 | 1·480 | | | | | Def. N. | 36°35'37" | s.e. by s. | 1·486 | -0·035 | +0·002 | 1·453 | Very unsteady, a swell from N. | | | | Def. N.S. | 36°12'45" | s.e.by E.½ E. | 1·507 | -0·040 | +0·001 | 1·468 | | | | | Def. S. | 37°10'46" | s.e.by E.½ E. | 1·474 | -0·040 | +0·001 | 1·435 | | | | | Def. N.S. | 53°40'46" | s.e.by E.½ E. | 1·497 | -0·040 | +0·006 | 1·463 | | | | | Def. N. | 36°08'44" | s.e. | 1·511 | -0·046 | +0·001 | 1·466 | A heavy swell, strong breeze, with a heavy sea running. | | | | Def. S. | 36°33'42" | s.e. | 1·507 | -0·046 | +0·001 | 1·462 | | | | | Def. N.S. | 53°22'39" | s.e. | 1·514 | -0·046 | +0·009 | 1·477 | | | | | Def. N. | 36°00'40" | s.e. | 1·519 | -0·046 | +0·001 | 1·474 | | | | | Def. S. | 36°33'39" | s.e. | 1·507 | -0·046 | +0·001 | 1·462 | | | | | Def. N.S. | 53°23'39" | s.e. | 1·513 | -0·046 | +0·009 | 1·476 | | | | | Def. N. | 36°01'40" | s.e. | 1·518 | -0·046 | +0·001 | 1·473 | Table unsteady, much motion. | | | | Def. S. | 36°37'40" | s.e. | 1·505 | -0·046 | +0·001 | 1·460 | | | | | Def. N.S. | 53°26'39" | s.e. | 1·511 | -0·046 | +0·009 | 1·474 | | | | | Mag. N. | 36°39'39" | s.e. | 1·525 | -0·046 | +0·003 | 1·482 | | | | | Mag. S. | 37°09'39" | s.e. | 1·500 | -0·046 | +0·003 | 1·457 | | | | | Def. N. | 35°41'42" | s.e.½ E. | 1·537 | -0·044 | +0·001 | 1·494 | | | | | Def. S. | 36°13'42" | s.e.½ E. | 1·527 | -0·044 | +0·001 | 1·484 | | | | | Def. N.S. | 53°21'40" | s.e.½ E. | 1·515 | -0·044 | +0·009 | 1·480 | Fresh breeze, table steady. | | | | Mag. N. | 36°14'39" | s.e.½ E. | 1·558 | -0·044 | +0·003 | 1·517 | | | | | Mag. S. | 36°19'39" | s.e.½ E. | 1·557 | -0·044 | +0·003 | 1·516 | | ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|-------------|-----------|--------------|---------------------|---------| | **1845** | | | | | | | | | | | | Feb. 26 | -61° 29' 57" 33" | Def. N. | 35° 11' 40" | S.E. ½ E. | 1·566 | -0·044 | +0·001 | 1·523 | Fresh breezes, table steady. | | | | | Def. S. | 35° 46' 40" | S.E. ½ E. | 1·552 | -0·044 | +0·001 | 1·509 | | | | | | Def. N.S. | 52° 55' 40" | S.E. ½ E. | 1·541 | -0·044 | +0·009 | 1·506 | | | | | | Def. N. | 35° 07' 40" | S.E. | 1·571 | -0·046 | +0·001 | 1·526 | | | | | | Def. S. | 35° 57' 40" | S.E. | 1·540 | -0·046 | +0·001 | 1·495 | | | | | | Def. N.S. | 52° 58' 40" | S.E. | 1·540 | -0·046 | +0·009 | 1·503 | | | | | | Mag. N. | 36° 24' 39" | S.E. | 1·543 | -0·046 | +0·003 | 1·500 | | | | | | Mag. S. | 36° 22' 38" | S.E. | 1·553 | -0·046 | +0·003 | 1·510 | | | | | | wt. 1 gr. | 12° 41' 38" | S.E. | 1·432 | -0·046 | -0·003 | 1·383* | | | | | | wt. 2 grs. | 25° 29' 38" | S.E. | 1·528 | -0·046 | -0·003 | 1·479 | | | | | | Def. N. | 34° 35' 39" | S.S.E. ½ E. | 1·602 | -0·048 | +0·002 | 1·556 | | | | | | Def. S. | 34° 49' 39" | S.S.E. ½ E. | 1·610 | -0·048 | +0·002 | 1·564 | Very unsteady. | | | | | Def. N. | 34° 47' 38" | S.S.E. | 1·651 | -0·049 | +0·002 | 1·604 | | | | | | Def. S. | 34° 15' 38" | S.S.E. | 1·644 | -0·049 | +0·002 | 1·597 | Very unsteady. | | | | | Def. N.S. | 51° 17' 37" | S.S.E. | 1·635 | -0·049 | +0·010 | 1·596 | | | | | | Mag. N. | 34° 35' 37" | S.S.E. | 1·680 | -0·049 | +0·003 | 1·634 | | | | | | Mag. S. | 35° 15' 35" | S.S.E. | 1·637 | -0·049 | +0·003 | 1·591 | | | | | | Def. N. | 33° 26' 35" | S.S.E. | 1·675 | -0·049 | +0·002 | 1·628 | Table steady. | | | | | Def. S. | 34° 27' 35" | S.S.E. | 1·632 | -0·049 | +0·002 | 1·585 | | | | | | Def. N.S. | 51° 05' 35" | S.S.E. | 1·646 | -0·049 | +0·011 | 1·608 | | | Mar. 1 | -62° 10' 72" 25" | Def. N. | 33° 14' 46" | S.E. by s. | 1·687 | -0·047 | +0·002 | 1·642 | Calm, table steady. | | | | | Def. S. | 33° 31' 46" | S.E. by s. | 1·692 | -0·047 | +0·002 | 1·647 | | | | | | Def. N.S. | 50° 33' 46" | S.E. by s. | 1·680 | -0·047 | +0·006 | 1·639 | | | | | | Mag. N. | 34° 24' 46" | S.E. by s. | 1·695 | -0·047 | +0·002 | 1·650 | | | | | | Mag. S. | 34° 49' 46" | S.E. by s. | 1·673 | -0·047 | +0·002 | 1·628 | | | | | | wt. 1 gr. | 10° 37' 46" | S.E. by s. | 1·706 | -0·047 | -0·002 | 1·657* | | | | | | wt. 2 grs. | 22° 49' 46" | S.E. by s. | 1·695 | -0·047 | -0·002 | 1·646 | | | | | | Def. N. | 33° 15' 42" | S.E.by E.½ E. | 1·687 | -0·047 | +0·001 | 1·641 | | | | | | Def. S. | 33° 30' 42" | S.E.by E.½ E. | 1·693 | -0·041 | +0·001 | 1·653 | | | | | | Def. N.S. | 50° 26' 42" | S.E.by E.½ E. | 1·686 | -0·041 | +0·008 | 1·653 | | | | | | Mag. N. | 34° 15' 42" | S.E.by E.½ E. | 1·706 | -0·041 | +0·003 | 1·668 | | | | | | Mag. S. | 34° 40' 42" | S.E.by E.½ E. | 1·685 | -0·041 | +0·003 | 1·647 | | | | | | wt. 1 gr. | 11° 02' 42" | S.E.by E.½ E. | 1·643 | -0·041 | -0·003 | 1·599* | Steady breeze, table steady. | | | | | wt. 2 grs. | 22° 31' 42" | S.E.by E.½ E. | 1·716 | -0·041 | -0·003 | 1·672 | | | | | | Def. N. | 32° 46' 42" | S. | 1·717 | -0·056 | +0·002 | 1·663 | | | | | | Def. S. | 33° 30' 42" | S. | 1·693 | -0·056 | +0·002 | 1·639 | | | | | | Def. N.S. | 50° 24' 42" | S. | 1·688 | -0·056 | +0·008 | 1·640 | | | | | | Def. N. | 32° 32' 34" | S.by w.½ w. | 1·732 | -0·054 | +0·003 | 1·681 | | | | | | Def. S. | 32° 58' 32" | S.by w.½ w. | 1·728 | -0·054 | +0·003 | 1·677 | Fresh breeze, unsteady, thick, with squalls of snow. | | | | | Def. N.S. | 49° 56' 31" | S.by w.½ w. | 1·717 | -0·054 | +0·014 | 1·677 | | | | | | Def. N. | 31° 35' 36" | S.E. ½ E. | 1·795 | -0·049 | +0·002 | 1·748 | Unsteady; aurora visible. | | | | | Def. S. | 32° 09' 37" | S.E. ½ E. | 1·783 | -0·049 | +0·002 | 1·736 | | | | | | Def. N.S. | 49° 35' 37" | S.E. ½ E. | 1·742 | -0·049 | +0·012 | 1·705 | | | | | | Def. N. | 31° 34' 39" | S.E. | 1·796 | -0·051 | +0·002 | 1·747 | | | | | | Def. S. | 32° 27' 39" | S.E. | 1·762 | -0·051 | +0·002 | 1·713 | | | | | | Def. N.S. | 49° 32' 38" | S.E. | 1·746 | -0·051 | +0·011 | 1·706 | Very unsteady, with thick weather. | | | | | Mag. N. | 32° 38' 37" | S.E. | 1·833 | -0·051 | +0·004 | 1·786 | | | | | | Mag. S. | 33° 01' 37" | S.E. | 1·830 | -0·051 | +0·004 | 1·783 | | | | | | Def. N. | 31° 46' 41" | S.S.W. | 1·783 | -0·053 | +0·002 | 1·732 | | | | | | Def. S. | 32° 14' 42" | S.S.W. | 1·779 | -0·053 | +0·002 | 1·728 | | | | | | Def. N.S. | 49° 00' 42" | S.S.W. | 1·785 | -0·053 | +0·009 | 1·741 | | | | | | Mag. N. | 32° 54' 42" | S.S.W. | 1·811 | -0·053 | +0·003 | 1·761 | | | | | | Mag. S. | 32° 57' 42" | S.S.W. | 1·834 | -0·053 | +0·003 | 1·784 | | * Omitted in mean. | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|------------|-----------|-------------|---------------------|-------------------------| | 1845. Mar. 8. | -61° 07' | 92° 10' | Def. N. | 31° 13' 41" | E.S.E. | 1·824 | -0·046 | +0·002 | 1·780 | Unsteady, with snow. | | | | | Def. S. | 32° 04' 40" | E.S.E. | 1·790 | -0·046 | +0·002 | 1·746 | | | | | | Def. N.S. | 49° 04' 38" | E.S.E. | 1·782 | -0·046 | +0·011 | 1·747 | | | | | | Def. N. | 31° 19' 40" | S.E. by E. | 1·817 | -0·048 | +0·002 | 1·771 | Very unsteady. | | | | | Def. S. | 32° 09' 41" | S.E. by E. | 1·784 | -0·048 | +0·002 | 1·738 | | | | | | Def. N.S. | 49° 08' 41" | S.E. by E. | 1·780 | -0·048 | +0·010 | 1·742 | | | | | | Def. N. | 31° 08' 39" | E.S.E. | 1·832 | -0·046 | +0·002 | 1·788 | | | | | | Def. S. | 31° 56' 38" | E.S.E. | 1·796 | -0·046 | +0·002 | 1·752 | | | | | | Def. N. | 29° 54' 35" | E. ½ N. | 1·919 | -0·041 | +0·002 | 1·880 | | | | | | Def. S. | 30° 31' 34" | E. ½ N. | 1·908 | -0·041 | +0·002 | 1·869 | | | | | | Def. N.S. | 48° 58' 34" | E. ½ N. | 1·788 | -0·041 | +0·013 | 1·760 | | | | | | Mag. N. | 32° 21' 34" | E. ½ N. | 1·855 | -0·041 | +0·004 | 1·818 | | | | | | Mag. S. | 32° 23' 34" | E. ½ N. | 1·888 | -0·041 | +0·004 | 1·851 | | | | | | Def. N. | 30° 34' 46" | E.N.E. | 1·870 | -0·039 | +0·001 | 1·832 | | | | | | Def. S. | 31° 28' 46" | E.N.E. | 1·831 | -0·039 | +0·001 | 1·793 | | | | | | Def. N. | 30° 31' 40" | E. by S. | 1·876 | -0·047 | +0·002 | 1·831 | | | | | | Def. S. | 31° 20' 41" | E. by S. | 1·842 | -0·047 | +0·002 | 1·797 | | | | | | Def. N.S. | 48° 35' 41" | E. by S. | 1·816 | -0·047 | +0·010 | 1·779 | | | | | | Def. N. | 30° 30' 41" | E.N.E. | 1·876 | -0·039 | +0·002 | 1·839 | | | | | | Def. S. | 31° 10' 41" | E.N.E. | 1·854 | -0·039 | +0·002 | 1·817 | | | | | | Def. N.S. | 48° 34' 41" | E.N.E. | 1·817 | -0·039 | +0·010 | 1·788 | | | | | | Def. N. | 30° 03' 39" | E. | 1·909 | -0·045 | +0·002 | 1·866 | | | | | | Def. S. | 31° 18' 38" | E. | 1·844 | -0·045 | +0·002 | 1·801 | | | | | | Def. N.S. | 48° 34' 38" | E. | 1·817 | -0·045 | +0·012 | 1·784 | | | | | | Def. N. | 29° 59' 39" | E. by S. | 1·913 | -0·047 | +0·002 | 1·868 | | | | | | Def. S. | 31° 05' 40" | E. by S. | 1·860 | -0·047 | +0·002 | 1·815 | | | | | | Def. N.S. | 48° 34' 40" | E. by S. | 1·817 | -0·047 | +0·011 | 1·781 | | | | | | Def. N. | 30° 28' 44" | N.E. | 1·878 | -0·036 | +0·002 | 1·844 | | | | | | Def. S. | 31° 14' 44" | N.E. | 1·849 | -0·036 | +0·002 | 1·815 | | | | | | Def. N.S. | 48° 30' 43" | N.E. | 1·822 | -0·036 | +0·009 | 1·795 | | | | | | Mag. N. | 31° 55' 43" | N.E. | 1·889 | -0·036 | +0·003 | 1·856 | | | | | | Mag. S. | 32° 48' 43" | N.E. | 1·850 | -0·036 | +0·003 | 1·817 | | | | | | Def. N. | 30° 52' 47" | N.E. ½ N. | 1·849 | -0·035 | +0·001 | 1·815 | | | | | | Def. S. | 31° 26' 48" | N.E. ½ N. | 1·834 | -0·035 | +0·001 | 1·800 | | | | | | Def. N.S. | 48° 22' 48" | N.E. ½ N. | 1·831 | -0·035 | +0·006 | 1·802 | | | | | | Mag. N. | 32° 20' 49" | N.E. ½ N. | 1·857 | -0·035 | +0·002 | 1·824 | | | | | | Mag. S. | 32° 58' 49" | N.E. ½ N. | 1·835 | -0·035 | +0·002 | 1·802 | | | | | | wt. 1 gr. | 9° 59' 50" | N.E. ½ N. | 1·813 | -0·035 | -0·003 | 1·776* | | | | | | wt. 2 grs. | 20° 01' 50" | N.E. ½ N. | 1·920 | -0·035 | -0·002 | 1·883 | | | | | | wt. 3 grs. | 31° 32' 50" | N.E. ½ N. | 1·859 | -0·035 | -0·002 | 1·822 | | | | | | Def. N. | 30° 38' 50" | N.W. ½ N. | 1·866 | -0·029 | +0·001 | 1·838 | | | | | | Def. S. | 30° 34' 50" | N.W. ½ N. | 1·897 | -0·029 | +0·001 | 1·869 | | | | | | Def. N.S. | 48° 29' 50" | N.W. ½ N. | 1·821 | -0·029 | +0·005 | 1·797 | | | | | | Mag. N. | 32° 07' 50" | N.W. ½ N. | 1·876 | -0·029 | +0·002 | 1·849 | | | | | | Mag. S. | 32° 26' 50" | N.W. ½ N. | 1·885 | -0·029 | +0·002 | 1·858 | | | | | | Def. N. | 31° 01' 49" | N. by E. | 1·840 | -0·020 | +0·001 | 1·821 | | | | | | Def. S. | 31° 21' 50" | N. by E. | 1·838 | -0·020 | +0·001 | 1·819 | | | | | | Def. N.S. | 31° 06' 55" | N. ½ E. | 1·833 | -0·020 | +0·000 | 1·813 | | | | | | Def. S. | 31° 49' 55" | N. ½ E. | 1·807 | -0·020 | +0·000 | 1·787 | | | | | | Def. N.S. | 48° 57' 55" | N. ½ E. | 1·789 | -0·020 | +0·002 | 1·771 | | | | | | Mag. N. | 32° 33' 55" | N. ½ E. | 1·840 | -0·020 | +0·001 | 1·821 | | | | | | Mag. S. | 33° 24' 56" | N. ½ E. | 1·793 | -0·020 | +0·001 | 1·774 | | | | | | wt. 1 gr. | 10° 20' 56" | N. ½ E. | 1·753 | -0·020 | -0·001 | 1·732* | | | | | | wt. 2 grs. | 20° 30' 56" | N. ½ E. | 1·877 | -0·020 | -0·001 | 1·856 | | * Omitted in mean. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|------------|-----------|-------------|---------------------|---------| | **1845.** | | | | | | | | | | | | Mar. 26. | -41° | 00' | Def. N. | 31° 40' 56" | N. by w. | 1·790 | -0·020 | 1·770 | | | | | | | Def. S. | 31° 37' 56" | N. by w. | 1·821 | -0·020 | 1·801 | | | | | | | Def. N.S. | 49° 41' 56" | N. by w. | 1·736 | -0·020 | +0·002 | 1·718 | | | | | | Mag. N. | 33° 19' 56" | N. by w. | 1·780 | -0·020 | +0·001 | 1·761 | | | | | | Mag. S. | 33° 46' 56" | N. by w. | 1·759 | -0·020 | +0·001 | 1·740 | | | 27. | -38° | 40' | Def. N. | 32° 33' 62" | N. by E. | 1·731 | -0·012 | 1·719 | | | | | | | Def. S. | 32° 35' 62" | N. by E. | 1·752 | -0·012 | 1·740 | | | | | | | Def. N.S. | 49° 55' 62" | N. by E. | 1·720 | -0·012 | 1·707 | | | | 28. | -37° | 00' | Def. N. | 33° 12' 63" | N. by E. | 1·689 | -0·012 | 1·677 | | | | | | | Def. S. | 33° 34' 64" | N. by E.½ E.| 1·687 | -0·012 | 1·675 | | | | | | | Def. N.S. | 50° 42' 64" | N. by E.½ E.| 1·670 | -0·012 | 1·656 | | | | | | | Mag. N. | 34° 06' 68" | N. by E.½ E.| 1·717 | -0·012 | 1·704 | | | | | | | Mag. S. | 34° 41' 68" | N. by E.½ E.| 1·681 | -0·012 | 1·668 | | | | | | | wt. 1 gr. | 11° 08' 68" | N. by E.½ E.| 1·628 | -0·012 | +0·001 | 1·617* | | | | | | wt. 2 grs. | 22° 48' 68" | N. by E.½ E.| 1·696 | -0·012 | +0·001 | 1·685 | | | | | | wt. 3 grs. | 35° 19' 65" | N. by E.½ E.| 1·682 | -0·012 | +0·001 | 1·671 | | | 29. | -36° | 11' | Def. N. | 33° 12' 67" | N.N.E. | 1·689 | -0·012 | 1·676 | | | | | | | Def. S. | 33° 21' 67" | N.N.E. | 1·702 | -0·012 | 1·689 | | | | | | | Def. N.S. | 50° 51' 68" | N.N.E. | 1·661 | -0·012 | 1·646 | | | | 30. | -35° | 07' | Def. N. | 32° 54' 66" | N.N.E. | 1·708 | -0·012 | 1·695 | | | | | | | Def. S. | 33° 13' 66" | N.N.E. | 1·712 | -0·012 | 1·699 | | | | | | | Def. N.S. | 50° 12' 66" | N.N.E. | 1·701 | -0·012 | 1·687 | | | | April 7. | | | Def. N. | 33° 11' 68" | N.N.E. | 1·690 | .... | 1·689 | | | | | | | Def. S. | 33° 32' 68" | N.N.E. | 1·690 | .... | 1·689 | | | | | | | Def. N.S. | 50° 24' 68" | N.N.E. | 1·689 | .... | 1·686 | | | | | | | Mag. N. | 34° 30' 68" | N.N.E. | 1·687 | .... | 1·686 | | | | | | | Mag. S. | 34° 34' 69" | Observed | 1·691 | .... | 1·690 | | | | | | | wt. 1 gr. | 10° 44' 69" | on shore. | 1·688 | .... | 1·689 | | | | | | | wt. 1½ gr. | 17° 16' 69" | on shore. | 1·688 | .... | 1·689 | | | | | | | wt. 2 grs. | 22° 56' 69" | on shore. | 1·688 | .... | 1·689 | | | | | | | wt. 2½ grs. | 28° 18' 69" | on shore. | 1·688 | .... | 1·689 | | | | | | | wt. 3 grs. | 35° 11' 69" | on shore. | 1·688 | .... | 1·689 | | | ### Needle B. | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|------------|-----------|-------------|---------------------|---------| | 12. | -35° | 02' | Def. N. | 29° 23' 64" | 1·711 | .... | 0·000 | 1·711 | | | | | | | Def. S. | 35° 31' 64" | 1·657 | .... | 0·000 | 1·657 | | | | | | | Def. N.S. | 50° 11' 64" | 1·679 | .... | 0·000 | 1·679 | | | | | | | Mag. N. | 31° 37' 64" | 1·658 | .... | 0·000 | 1·658 | | | | | | | Mag. S. | 36° 25' 62" | 1·653 | .... | 0·000 | 1·653 | | | | | | | wt. 1 gr. | 16° 13' 62" | 1·693 | .... | 0·000 | 1·693 | | | | | | | wt. 1½ gr. | 24° 39' 62" | 1·672 | .... | 0·000 | 1·672 | | | | | | | wt. 2 grs. | 33° 27' 62" | 1·698 | .... | 0·000 | 1·698 | | | | 23. | -35° | 30' | Def. N. | 30° 03' 66" | N.W. | 1·670 | -0·011 | 1·659 | | | | | | | Def. S. | 35° 01' 66" | N.W. | 1·687 | -0·011 | 1·675 | | | | | | | Def. N.S. | 49° 55' 66" | N.W. | 1·696 | -0·011 | 1·683 | | | | 25. | -32° | 24' | Def. N. | 31° 07' 69" | N.W. by N. | 1·602 | -0·011 | 1·590 | | | | | | | Def. S. | 36° 26' 69" | N.W. by N. | 1·603 | -0·011 | 1·591 | | | | | | | Def. N.S. | 51° 30' 69" | N.W. by N. | 1·599 | -0·011 | 1·584 | | | | | | | Mag. N. | 33° 14' 69" | N.W. by N. | 1·547 | -0·011 | 1·535 | | | | | | | Mag. S. | 37° 23' 69" | N.W. by N. | 1·577 | -0·011 | 1·565 | | | | 27. | -29° | 16' | Def. N. | 32° 17' 72" | W.N.W. | 1·534 | -0·015 | 1·518 | | | | | | | Def. S. | 37° 53' 72" | W.N.W. | 1·515 | -0·015 | 1·499 | | | | | | | Def. N.S. | 53° 15' 72" | W.N.W. | 1·501 | -0·015 | 1·481 | | | * Omitted in mean. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|---------| | 1845. | | | Def. N. | 33° 30' 75" | N. by w. | 1·467 | +·002 | −·001 | 1·468 | Unsteady, a heavy swell. | | | | | Def. S. | 37° 36' 76" | N. by w. | 1·532 | +·002 | −·001 | 1·533 | | | | | | Def. N.S. | 53° 30' 76" | N. by w. | 1·483 | +·002 | −·006 | 1·479 | | | | | | Mag. N. | 34° 36' 76" | N. by w. | 1·459 | +·002 | −·002 | 1·459 | | | | | | Mag. S. | 39° 06' 76" | N. by w. | 1·451 | +·002 | −·002 | 1·451 | | | | | | Def. N. | 33° 47' 68" | N.W. | 1·450 | −·003 | −·001 | 1·446 | Very unsteady. | | | | | Def. S. | 39° 02' 68" | W. | 1·453 | −·003 | −·001 | 1·449 | | | | | | Def. N. | 34° 30' 68" | W. | 1·414 | −·022 | −·001 | 1·391 | Unsteady. | | | | | Def. S. | 39° 54' 68" | W. | 1·407 | −·022 | −·001 | 1·384 | | | | | | Def. N.S. | 55° 14' 68" | W. | 1·394 | −·022 | −·003 | 1·369 | | | | | | Def. N. | 34° 32' 72" | W. ½ N. | 1·412 | −·019 | −·001 | 1·392 | Unsteady. | | | | | Def. S. | 40° 02' 72" | W. ½ N. | 1·402 | −·019 | −·001 | 1·382 | | | | | | Def. N.S. | 55° 15' 72" | W. ½ N. | 1·394 | −·019 | −·005 | 1·370 | | | | | | Def. N. | 35° 00' 76" | W. ½ N. | 1·388 | −·019 | −·001 | 1·368 | | | | | | Def. S. | 40° 16' 76" | W. ½ N. | 1·389 | −·019 | −·001 | 1·369 | | | | | | Def. N.S. | 55° 38' 76" | W. ½ N. | 1·378 | −·019 | −·006 | 1·353 | | | | | | wt. 1 gr. | 19° 28' 76" | W. ½ N. | 1·419 | −·019 | +·001 | 1·401 | Steady. | | | | | wt. 1½ gr. | 29° 58' 76" | W. ½ N. | 1·396 | −·019 | +·001 | 1·378 | | | | | | wt. 2 grs. | 41° 30' 76" | W. ½ N. | 1·413 | −·019 | +·001 | 1·395 | | | | | | Def. N. | 35° 21' 76" | W.N.W. | 1·371 | −·010 | −·001 | 1·360 | Unsteady. | | | | | Def. S. | 41° 05' 76" | W.N.W. | 1·350 | −·010 | −·001 | 1·339 | | | | | | Def. N.S. | 55° 45' 76" | W.N.W. | 1·369 | −·010 | −·001 | 1·358 | | | | | | Def. N. | 35° 51' 73" | N.W. | 1·347 | +·008 | −·001 | 1·354 | Cross sea, much rolling motion. | | | | | Def. S. | 40° 37' 73" | N.W. | 1·373 | +·008 | −·001 | 1·367 | | | | | | Def. N. | 36° 30' 73" | N.W. ½ W. | 1·316 | +·004 | −·001 | 1·319 | Table unsteady. | | | | | Def. S. | 42° 13' 73" | N.W. ½ W. | 1·298 | +·004 | −·001 | 1·314 | | | | | | Def. N.S. | 56° 45' 73" | N.W. ½ W. | 1·322 | +·004 | −·005 | 1·321 | | | | | | Def. N. | 36° 39' 77" | N.W. ½ W. | 1·309 | +·004 | −·001 | 1·312 | Unsteady. | | | | | Def. S. | 42° 49' 77" | N.W. ½ W. | 1·270 | +·004 | −·001 | 1·273 | | | | | | Def. N.S. | 56° 58' 77" | N.W. ½ W. | 1·312 | +·004 | −·006 | 1·310 | | | | | | Def. N. | 36° 56' 77" | N.W. ½ N. | 1·295 | −·015 | −·001 | 1·279 | Heavy swell. | | | | | Def. S. | 42° 49' 77" | N.W. ½ N. | 1·270 | −·015 | −·001 | 1·254 | | | | | | Def. N.S. | 57° 46' 77" | N.W. ½ N. | 1·276 | −·015 | −·006 | 1·253 | | | | | | Def. N. | 37° 46' 77" | N.W. ½ N. | 1·260 | −·012 | −·001 | 1·247 | | | | | | Def. S. | 42° 48' 76" | N.W. ½ N. | 1·270 | −·012 | −·001 | 1·257 | | | | | | Def. N.S. | 57° 46' 76" | N.W. ½ N. | 1·276 | −·012 | −·006 | 1·258 | Heavy swell. | | | | | Mag. N. | 38° 04' 76" | N.W. ½ N. | 1·256 | −·012 | −·001 | 1·243 | | | | | | Mag. S. | 42° 13' 76" | N.W. ½ N. | 1·249 | −·012 | −·001 | 1·236 | | | | | | Def. N. | 39° 00' 78" | N.W. ½ N. | 1·207 | −·012 | −·001 | 1·194 | | | | | | Def. S. | 43° 29' 78" | N.W. ½ N. | 1·239 | −·012 | −·001 | 1·226 | | | | | | Def. N.S. | 58° 28' 78" | N.W. ½ N. | 1·247 | −·012 | −·007 | 1·228 | | | | | | Mag. S. | 42° 44' 78" | N.W. ½ N. | 1·220 | −·012 | −·002 | 1·206 | | | | | | Def. N. | 37° 23' 87" | S. | 1·275 | −·040 | −·002 | 1·233 | | | | | | Def. N. | 37° 12' 87" | S.S.W. | 1·283 | −·036 | −·002 | 1·245 | | | | | | Def. N. | 37° 14' 87" | S.W. | 1·252 | −·032 | −·002 | 1·248 | | | | | | Def. N. | 38° 13' 87" | W.S.W. | 1·241 | −·023 | −·002 | 1·216 | | | | | | Def. N. | 38° 28' 87" | W. | 1·229 | −·016 | −·002 | 1·211 | | | | | | Def. N. | 38° 27' 87" | W.N.W. | 1·230 | −·007 | −·002 | 1·221 | | | | | | Def. N. | 37° 47' 86" | N.W. | 1·230 | −·001 | −·002 | 1·221 | | | | | | Def. N. | 38° 14' 84" | N.N.W. | 1·258 | −·001 | −·002 | 1·255 | | | | | | Def. N. | 38° 11' 80" | N. | 1·242 | +·002 | −·001 | 1·243 | | | | | | Def. N. | 38° 28' 78" | N.N.E. | 1·229 | +·000 | −·001 | 1·228 | | | | | | Def. N. | 38° 17' 78" | N.E. | 1·236 | −·001 | −·001 | 1·234 | | | | | | Def. N. | 38° 00' 78" | E.N.E. | 1·249 | −·007 | −·001 | 1·241 | | These observations were made to determine the effect of the ship's iron at sea. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|---------------------|------------|------------|-----------|-------------|---------------------|---------| | 1845. May 13. | -20° 39' | 77° 43' | Def. N. | 37° 41' | S.E. | 1·262 | -0·032 | -0·001 | 1·229 | Made to determine the effect of the ship's iron at sea. | | | | | Def. N. | 38° 00' | E. | 1·249 | -0·016 | -0·001 | 1·232 | | | | | | Def. N. | 37° 40' | N.E. | 1·264 | -0·001 | -0·001 | 1·262 | | | | | | Def. N. | 38° 24' | N. | 1·232 | +0·002 | -0·001 | 1·233 | | | | | | Def. N. | 38° 31' | N.W. | 1·238 | -0·001 | -0·001 | 1·226 | A rolling motion, not very steady at some points. | | | | | Def. N. | 38° 20' | W. | 1·235 | -0·016 | -0·001 | 1·218 | | | | | | Def. N. | 38° 40' | W. by N. | 1·221 | -0·011 | -0·001 | 1·209 | | | | | | Def. S. | 43° 52' | W. by N. | 1·221 | -0·011 | -0·001 | 1·209 | | | | | | Def. N.S. | 59° 26' | W. by N. | 1·214 | -0·011 | -0·007 | 1·196 | | | | | | Def. N. | 38° 37' | W. by N. | 1·222 | -0·011 | -0·001 | 1·210 | | | | | | Def. S. | 43° 59' | W. by N. | 1·217 | -0·011 | -0·001 | 1·205 | | | | | | Def. N.S. | 59° 09' | W. by N. | 1·222 | -0·011 | -0·007 | 1·204 | | | | | | Def. N. | 38° 09' | S.W.by.W.½W.| 1·243 | -0·030 | -0·001 | 1·212 | | | | | | Def. S. | 43° 17' | S.W.by.W.½W.| 1·248 | -0·030 | -0·001 | 1·217 | | | | | | Def. N.S. | 58° 34' | S.W.by.W.½W.| 1·243 | -0·030 | -0·007 | 1·206 | | | | | | Mag. N. | 38° 23' | S.W.by.W.½W.| 1·237 | -0·030 | -0·002 | 1·205 | | | | | | Mag. S. | 42° 07' | S.W.by.W.½W.| 1·253 | -0·030 | -0·002 | 1·221 | | | | | | Def. N. | 38° 57' | N.W. | 1·209 | -0·001 | -0·001 | 1·207 | | | | | | Def. S. | 44° 17' | N.W. | 1·203 | -0·001 | -0·001 | 1·201 | Unsteady. | | | | | Def. N.S. | 59° 54' | N.W. | 1·196 | -0·001 | -0·005 | 1·190 | | | | | | Mag. N. | 38° 52' | N.W. | 1·211 | -0·001 | -0·001 | 1·209 | | | | | | wt. 1 gr. | 22° 44' | N.W. | 1·223 | -0·001 | +0·001 | 1·223 | | | | | | wt. 1½ gr. | 35° 01' | N.W. | 1·215 | -0·001 | +0·001 | 1·215 | Steady. | | | | | wt. 2 grs. | 51° 35' | N.W. | 1·195 | -0·001 | +0·001 | 1·195 | | | | | | Def. N. | 39° 02' | W. by N. | 1·205 | -0·012 | -0·001 | 1·192 | | | | | | Def. S. | 44° 03' | W. by N. | 1·212 | -0·012 | -0·001 | 1·199 | | | | | | Def. N.S. | 59° 59' | W. by N. | 1·194 | -0·012 | -0·004 | 1·178 | | | | | | Def. N. | 39° 03' | W. by N. | 1·204 | -0·012 | -0·001 | 1·191 | | | | | | Def. S. | 44° 29' | W. by N. | 1·195 | -0·012 | -0·001 | 1·182 | | | | | | Def. N.S. | 59° 40' | W. by N. | 1·204 | -0·012 | -0·005 | 1·187 | | | | | | Mag. N. | 39° 14' | W. by N. | 1·194 | -0·012 | -0·001 | 1·181 | | | | | | Mag. S. | 43° 48' | W. by N. | 1·163 | -0·012 | -0·001 | 1·150 | | | | | | Def. N. | 39° 28' | W. by N. | 1·189 | -0·012 | -0·001 | 1·176 | | | | | | Def. S. | 45° 01' | W. by N. | 1·173 | -0·012 | -0·001 | 1·160 | | | | | | Def. N.S. | 59° 41' | W. by N. | 1·203 | -0·012 | -0·005 | 1·186 | | | | | | Mag. N. | 39° 28' | W. by N. | 1·181 | -0·012 | -0·001 | 1·168 | | | | | | Def. N. | 40° 07' | W. by N. | 1·165 | -0·001 | -0·001 | 1·164 | | | | | | Def. S. | 45° 28' | W. by N. | 1·153 | -0·001 | -0·001 | 1·152 | | | | | | Def. N.S. | 60° 43' | W. by N. | 1·167 | -0·006 | -0·001 | 1·161 | | | | | | Mag. N. | 39° 55' | On shore | 1·158 | -0·001 | -0·001 | 1·157 | Steady. | | | | | Mag. S. | 44° 14' | at Mauritius.| 1·138 | -0·001 | -0·001 | 1·137 | | | | | | wt. 1 gr. | 23° 59' | | 1·163 | +0·001 | -0·001 | 1·164 | | | | | | wt. 1½ gr.* | 33° 46' | | 1·255 | +0·001 | -0·001 | 1·256* | Steady. | | | | | wt. 2 grs. | 54° 42' | | 1·147 | +0·001 | -0·001 | 1·148 | | | | | | Def. N. | 39° 41' | S.W.by.W. | 1·182 | -0·027 | -0·001 | 1·154 | Unsteady. | | | | | Def. S. | 44° 25' | S.W.by.W. | 1·198 | -0·027 | -0·001 | 1·170 | | | | | | Def. N.S. | 59° 59' | S.W.by.W. | 1·194 | -0·027 | -0·008 | 1·159 | | | | | | Def. N. | 39° 31' | N.W.by.W. | 1·187 | -0·005 | -0·001 | 1·181 | | | | | | Def. S. | 45° 18' | N.W.by.W. | 1·161 | -0·005 | -0·001 | 1·155 | | | | | | Def. N.S. | 60° 41' | N.W.by.W. | 1·168 | -0·005 | -0·006 | 1·157 | | | | | | Def. N. | 39° 44' | W. | 1·179 | -0·018 | -0·001 | 1·160 | | | | | | Def. S. | 44° 39' | W. | 1·188 | -0·018 | -0·001 | 1·169 | | | | | | Def. N.S. | 60° 38' | W. | 1·169 | -0·018 | -0·003 | 1·148 | | * This observation is evidently wrong, and is omitted in the mean. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|--------|--------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|-----------------| | 1845. | | | | | | | | | | | | June 8. | -28° 57' | 37° 55' | Def. N. | 40° 36' 74° | w. | 1·147 | -·018 | -·001 | 1·128 | | | | | | Def. S. | 46° 11' 76° | w. | 1·124 | -·018 | -·001 | 1·105 | Steady. | | | | | Def. N.S. | 61° 44' 77° | w. | 1·131 | -·018 | -·005 | 1·108 | | | | | | Mag. N. | 40° 27' 77° | w. | 1·132 | -·018 | -·001 | 1·113 | | | | | | Mag. S. | 44° 33' 77° | w. | 1·121 | -·018 | -·001 | 1·102 | | | 11. | -30° 27' | 33° 41' | Def. N. | 41° 32' 79° | W.N.W. | 1·114 | -·008 | -·001 | 1·105 | Very unsteady. | | 13. | -31° 06' | 31° 26' | Def. N. | 41° 58' 79° | W. by s. ½ s. | 1·098 | -·024 | -·001 | 1·073 | | | | | | Def. S. | 47° 30' 79° | W. by s. ½ s. | 1·079 | -·024 | -·001 | 1·054 | | | | | | Def. N.S. | 61° 41' 79° | W. by s. ½ s. | 1·131* | -·024 | -·006 | 1·101* | | | 17. | -35° 40' | 21° 40' | Def. N. | 43° 12' 62° | W. by N. | 1·053 | -·013 | -·000 | 1·040 | | | | | | Def. N.S. | 64° 49' 62° | W. by N. | 1·038 | -·013 | -·000 | 1·025 | Unsteady. | | 23. | Simon's Bay, | Cape of Good Hope. | Def. N. | 43° 22' 68° | S. | 1·047 | -·040 | -·001 | 1·006 | | | | | | Def. N. | 43° 41' 67° | S.E. | 1·036 | -·032 | -·000 | 1·004 | | | | | | Def. N. | 44° 14' 67° | E. | 1·117 | -·016 | -·000 | 1·001 | | | | | | Def. N. | 44° 35' 67° | N.E. | 1·004 | -·001 | -·000 | 1·003 | | | | | | Def. N. | 44° 40' 67° | N. | 1·001 | +·002 | -·000 | 1·001 | | | | | | Def. N. | 44° 46' 67° | N.W. | 1·997 | -·001 | -·000 | 0·996 | | | | | | Def. N. | 44° 20' 70° | W. | 1·013 | -·016 | -·001 | 0·996 | | | | | | Def. N. | 43° 50' 70° | S.W. | 1·032 | -·032 | -·001 | 0·999 | | | 24. | Simon's Bay, | at the Dock Yard. | Def. N. | 44° 38' 68° | Face East, on shore. | 1·004 | -·001 | -·001 | 1·003 | | | | | | Def. N. | 50° 14' 68° | Face East, on shore. | 0·990* | -·001 | -·001 | 0·989* | | | | | | Def. N.S. | 66° 16' 68° | On shore. | 1·002 | -·002 | -·000 | 1·000 | | | | | | Needle N. | 45° 01' 61° | On shore. | 0·989 | -·000 | -·000 | 0·989 | | | | | | Needle S. | 49° 59' 62° | On shore. | 0·996 | -·000 | -·000 | 0·996 | | | | | | Mag. N.S. | 66° 20' 63° | On shore. | 0·997 | -·001 | -·001 | 0·996 | | | | | | Mag. N. | 43° 45' 64° | On shore. | 0·989 | -·000 | -·000 | 0·989 | | | | | | Mag. S. | 47° 23' 64° | On shore. | 0·997 | -·000 | -·000 | 0·997 | | | | | | Needle S. | 44° 33' 61° | On shore. | 1·005 | -·000 | -·000 | 1·005 | | | | | | Needle S. | 49° 42' 62° | On shore. | 1·005 | -·000 | -·000 | 1·005 | | | | | | Needle N.S. | 66° 16' 63° | On shore. | 0·998 | -·061 | -·001 | 0·997 | | | | | | Mag. N. | 43° 15' 63° | On shore. | 1·006 | -·000 | -·000 | 1·006 | | | | | | Mag. S. | 47° 20' 64° | On shore. | 0·999 | -·000 | -·000 | 0·999 | | | | | | wt. 1 gr. | 28° 26' 56° | On shore. | 0·993 | -·000 | -·000 | 0·993 | | | | | | wt. 1½ gr. | 44° 16' 57° | On shore. | 0·999 | -·000 | -·000 | 0·999 | | | | | | wt. 2 grs. | 69° 15' 58° | On shore. | 1·001 | -·000 | -·000 | 1·001 | | | | | | Def. N. | 44° 31' 75° | On shore. | 1·006 | -·001 | -·001 | 1·005 | | | | | | Def. S. | 49° 48' 75° | On shore. | 1·002 | -·001 | -·001 | 1·001 | | | | | | Mag. N.S. | 66° 02' 75° | On shore. | 1·003 | -·004 | -·001 | 0·999 | | | | | | Mag. N. | 43° 21' 76° | On shore. | 1·002 | -·001 | -·001 | 1·001 | | | | | | Mag. S. | 47° 13' 76° | On shore. | 1·004 | -·001 | -·001 | 1·003 | | | | | | wt. 1 gr. | 28° 00' 76° | On shore. | 1·007 | +·001 | -·001 | 1·008 | | | | | | wt. 1½ gr. | 44° 10' 76° | On shore. | 1·001 | +·001 | -·001 | 1·002 | | | | | | wt. 2 grs. | 69° 31' 76° | On shore. | 0·999 | +·001 | -·001 | 1·000 | | * Not included in mean. Observations of the Magnetic Force made on board Her Majesty's hired Bark "Pagoda," from the 1st of December 1844 to the 2nd of July 1845. Needle 1. Fox No. 1.; Face West; time usually two hours before Noon. Observer, Lieut. H. Clerk, R.A. | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|--------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|---------| | 1844. Dec. 1. | -33° 56' 18" 29" | Def. N. | 39° 06' 65° | 1·006 | -0·001 | 1·006 | | | | | Def. S. | 40° 38' 67° | 1·001 | -0·001 | 1·000 | | | | | Def. N.S. | 59° 23' 68° | 0·981 | -0·001 | 0·980 | | | | | wt. 1 gr. | 21° 29' 70° | 1·009 | +0·001 | 1·010 | | | | | wt. 2 grs. | 46° 54' 71° | 0·995 | +0·001 | 0·996 | | | | | wt. 2½ grs. | 65° 22' 72° | Observed | +0·001 | 1·001 | 0·999 | | | | Def. N. | 39° 01' 72° | 1·008 | -0·001 | 1·007 | | | | | Def. S. | 40° 37' 72° | 1·001 | -0·001 | 1·000 | | | | | Def. N.S. | 59° 22' 73° | 0·983 | -0·003 | 0·980 | | | | | wt. 1 gr. | 21° 34' 74° | 1·006 | +0·001 | 1·007 | | | | | wt. 2 grs. | 46° 33' 74° | 1·001 | +0·001 | 1·002 | | | | | wt. 2½ grs. | 65° 19' 74° | 1·007 | -0·001 | 1·006 | | | | | Def. N. | 39° 04' 74° | 1·007 | -0·001 | 1·006 | | | | | Def. S. | 40° 25' 76° | 1·007 | -0·001 | 1·006 | | | | | Def. N.S. | 59° 11' 78° | Observed | +0·001 | 1·005 | | | | | wt. 1 gr. | 21° 04' 78° | 1·029 | +0·001 | 1·030 | | | | | wt. 2 grs. | 46° 30' 78° | 1·002 | +0·001 | 1·003 | | | | | wt. 2½ grs. | 65° 49' 78° | 0·997 | +0·001 | 0·998 | | | 1845. Jan. 10. | -34° 44' 17" 50" | Def. N. | 39° 42' 70° | w. by n. | 0·986 | -0·009 | 0·976 | Table unsteady. | | | | Def. S. | 40° 39' 70° | w. by n. | 1·000 | -0·009 | 0·990 | | | | | Def. N.S. | 59° 11' 70° | w. by n. | 0·988 | -0·009 | 0·977 | | | | | Def. N. | 40° 02' 72° | s.w. by w. | 0·976 | -0·030 | 0·945 | | | | | Def. S. | 40° 40' 72° | s.w. by w. | 0·999 | -0·030 | 0·968 | | | | | Def. N.S. | 59° 25' 75° | s.w. ½ w. | 0·980 | -0·040 | 0·937 | | | | | wt. 1 gr. | 22° 00' 70° | s.w. ½ w. | 0·987 | -0·040 | 0·948 | Table steady. | | | | wt. 2 grs. | 47° 02' 69° | s.w. ½ w. | 0·992 | -0·040 | 0·953 | | | | | wt. 2½ grs. | 67° 01' 68° | s.w. ½ w. | 0·987 | -0·040 | 0·948 | | | | | Def. N. | 38° 52' 65° | s. by w. | 1·013 | -0·042 | 0·971 | Table unsteady. | | | | Def. S. | 40° 22' 65° | s. by w. | 1·009 | -0·042 | 0·967 | | | | | Def. N.S. | 58° 50' 65° | s. by w. | 1·000 | -0·042 | 0·957 | | | | | Def. N. | 38° 55' 62° | n.w.by w. | 1·012 | +0·003 | 1·015 | Very unsteady. | | | | Def. S. | 39° 55' 62° | n.w.by w. | 1·023 | +0·003 | 1·026 | | | | | Def. N.S. | 59° 25' 66° | n.w.by w. | 0·980 | +0·003 | 0·982 | | | | | Def. N. | 38° 47' 63° | s.w.byw.½w. | 1·016 | -0·026 | 0·990 | | | | | Def. S. | 39° 35' 63° | s.w.byw.½w. | 1·034 | -0·026 | 1·008 | | | | | Def. N.S. | 58° 30' 63° | s.w.byw.½w. | 1·009 | -0·026 | 0·982 | | | | | wt. 1 gr. | 21° 32' 64° | s.w.byw.½w. | 1·008 | -0·026 | 0·982 | Table steady. | | | | wt. 2 grs. | 45° 22' 65° | s.w.byw.½w. | 1·021 | -0·026 | 0·995 | | | | | wt. 2½ grs. | 64° 42' 67° | s.w.byw.½w. | 1·005 | -0·026 | 0·979 | | | | | Def. N. | 38° 42' 64° | s.w.by w. | 1·019 | -0·029 | 0·990 | Much motion. | | | | Def. S. | 39° 25' 65° | s.w.by w. | 1·039 | -0·029 | 1·010 | | | | | Def. N.S. | 58° 27' 65° | s.w.by w. | 1·011 | -0·029 | 0·981 | | | | | Def. N. | 38° 32' 60° | s.s.w. | 1·025 | -0·040 | 0·985 | Much motion. | | | | Def. S. | 38° 35' 59° | s.s.w. | 1·066 | -0·040 | 1·026 | | | | | Def. N.S. | 58° 07' 58° | s.s.w. | 1·021 | -0·040 | 0·981 | | | | | Def. N. | 38° 17' 48° | s.w.by s. | 1·033 | -0·037 | 0·997 | Much motion. | | | | Def. S. | 39° 02' 45° | s.w.by s. | 1·051 | -0·037 | 1·015 | | | | | Def. N.S. | 57° 27' 44° | s.w.by s. | 1·044 | -0·037 | 1·010 | | MDCCCXLVI. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|--------------------|-------------|------------|-----------|--------------|---------------------|---------| | Jan. 21 | -47° 40' | 12° 25' | Def. N. | 36° 30' | s. by E. | 1-091 | -0.041 | +0.001 | 1-051 | Very unsteady. | | | -48° 35' | 10° 51' | Def. N. | 36° 15' | s.w. by s. | 1-101 | -0.037 | +0.001 | 1-065 | Table steady. | | | | | Def. S. | 37° 35' | s.w. by s. | 1-104 | -0.037 | +0.001 | 1-068 | Table steady. | | | | | Def. N.S. | 56° 28' | s.w. by s. | 1-080 | -0.037 | +0.003 | 1-046 | Table steady. | | | | | Def. N. | 35° 10' | s.w. by s. | 1-140 | -0.036 | +0.001 | 1-105 | Table steady. | | | | | Def. S. | 36° 37' | s.w. by s. | 1-141 | -0.036 | +0.001 | 1-106 | Table steady. | | | | | Def. N.S. | 55° 47' | s.w. by s. | 1-105 | -0.036 | +0.003 | 1-072 | Table steady. | | | | | Def. N. | 34° 47' | s.w. by w. | 1-154 | -0.029 | +0.001 | 1-126 | Table steady. | | | | | Def. S. | 36° 10' | s.w. by w. | 1-158 | -0.029 | +0.001 | 1-130 | Table steady. | | | | | Def. N.S. | 55° 07' | s.w. by w. | 1-131 | -0.029 | +0.003 | 1-105 | Table steady. | | | | | Def. N. | 34° 57' | s.w. by w. | 1-148 | -0.029 | +0.001 | 1-120 | Rather unsteady. | | | | | Def. S. | 35° 47' | s.w. by w. | 1-173 | -0.029 | +0.001 | 1-145 | Table steady. | | | | | Def. N.S. | 55° 17' | s.w. by w. | 1-125 | -0.029 | +0.004 | 1-100 | Very steady. | | | | | Def. N. | 34° 22' | w. by s. | 1-171 | -0.020 | +0.001 | 1-152 | Table steady. | | | | | Def. S. | 35° 42' | w. by s. | 1-175 | -0.020 | +0.001 | 1-156 | Table steady. | | | | | Def. N.S. | 54° 30' | w. by s. | 1-155 | -0.020 | +0.003 | 1-138 | Table steady. | | | | | wt. 1 gr. | 18° 12' | w. by s. | 1-185 | -0.020 | +0.001 | 1-164 | Table steady. | | | | | wt. 2 grs. | 39° 40' | w. by s. | 1-138 | -0.020 | +0.001 | 1-117 | Table steady. | | | | | wt. 2½ grs. | 51° 50' | w. by s. | 1-155 | -0.020 | +0.001 | 1-134 | Table steady. | | | | | Def. N. | 33° 05' | s.s.w. by s.| 1-221 | -0.038 | +0.002 | 1-185 | Table steady. | | | | | Def. S. | 35° 52' | s.s.w. by s.| 1-201 | -0.038 | +0.002 | 1-165 | Table steady. | | | | | Def. N.S. | 54° 12' | s.s.w. by s.| 1-167 | -0.038 | +0.005 | 1-134 | Table steady. | | | | | Def. N.S. | 51° 57' | s. | 1-262 | -0.049 | +0.006 | 1-219 | Table steady. | | | | | Def. N.S. | 51° 35' | s.e. by E. | 1-282 | -0.034 | +0.006 | 1-254 | Table steady. | | | | | Def. N.S. | 52° 22' | N. | 1-246 | -0.004 | +0.006 | 1-248 | Table steady. | | | | | Def. N. | 30° 57' | s.e. by s. | 1-320 | -0.044 | +0.002 | 1-278 | Table steady. | | | | | Def. S. | 31° 55' | s.e. by s. | 1-339 | -0.044 | +0.002 | 1-297 | Table steady. | | | | | Def. N.S. | 51° 22' | s.e. by s. | 1-294 | -0.044 | +0.005 | 1-255 | Table steady. | | | | | wt. 1 gr. | 16° 02' | s.e. by s. | 1-340 | -0.044 | +0.001 | 1-295 | Table steady. | | | | | wt. 2 grs. | 32° 22' | s.e. by s. | 1-343 | -0.044 | +0.001 | 1-298 | Table steady. | | | | | wt. 2½ grs. | 43° 02' | s.e. by s. | 1-332 | -0.044 | +0.001 | 1-287 | Table steady. | | | | | Def. N. | 29° 57' | E.S.E. | 1-368 | -0.032 | +0.003 | 1-339 | Table steady. | | | | | Def. S. | 30° 57' | E.S.E. | 1-384 | -0.032 | +0.003 | 1-355 | Table steady. | | | | | Def. N.S. | 50° 45' | E.S.E. | 1-325 | -0.032 | +0.006 | 1-299 | Table steady. | | | | | Def. N. | 30° 10' | E.S.E. | 1-348 | -0.032 | +0.002 | 1-318 | Table steady. | | | | | Def. S. | 31° 20' | E.S.E. | 1-366 | -0.032 | +0.002 | 1-336 | Table steady. | | | | | Def. N.S. | 50° 20' | E.S.E. | 1-346 | -0.032 | +0.006 | 1-320 | Table steady. | | | | | wt. 1 gr. | 15° 05' | E.S.E. | 1-420 | -0.032 | +0.002 | 1-386 | Table steady. | | | | | wt. 2 grs. | 31° 55' | E.S.E. | 1-376 | -0.032 | +0.002 | 1-342 | Table steady. | | | | | wt. 2½ grs. | 42° 57' | E.S.E. | 1-336 | -0.032 | +0.002 | 1-302 | Table steady. | | | | | Def. N. | 29° 30' | S.S.E. | 1-388 | -0.046 | +0.003 | 1-345 | Table steady. | | | | | Def. S. | 30° 37' | S.S.E. | 1-401 | -0.046 | +0.003 | 1-358 | Table steady. | | | | | Def. N.S. | 49° 27' | S.S.E. | 1-396 | -0.046 | +0.006 | 1-356 | Table steady. | | | | | Def. N. | 28° 00' | S.S.E. | 1-461 | -0.050 | +0.003 | 1-414 | Table steady. | | | | | Def. S. | 29° 57' | S.S.E. | 1-435 | -0.050 | +0.003 | 1-388 | Table steady. | | | | | Def. N.S. | 49° 02' | S.S.E. | 1-422 | -0.050 | +0.007 | 1-379 | Table steady. | | | | | wt. 1 gr. | 14° 17' | S.S.E. | 1-499 | -0.050 | +0.002 | 1-447 | Table steady. | | | | | wt. 2 grs. | 30° 00' | S.S.E. | 1-454 | -0.050 | +0.002 | 1-402 | Table steady. | | | | | wt. 2½ grs. | 39° 40' | S.S.E. | 1-425 | -0.050 | +0.002 | 1-373 | Table steady. | | | | | Def. N. | 27° 37' | S.S.E. by s.| 1-481 | -0.049 | +0.002 | 1-434 | Table steady. | | | | | Def. S. | 28° 57' | S.S.E. by s.| 1-486 | -0.049 | +0.002 | 1-439 | Table steady. | | | | | Def. N.S. | 48° 17' | S.S.E. by s.| 1-466 | -0.049 | +0.005 | 1-422 | Table steady. | | | | | Def. N. | 26° 52' | E. | 1-519 | -0.026 | +0.004 | 1-497 | Table steady. | | | | | Def. S. | 28° 35' | E. | 1-506 | -0.026 | +0.004 | 1-484 | Table steady. | | | | | Def. N.S. | 48° 00' | E. | 1-483 | -0.026 | +0.008 | 1-465 | Table steady. | | | | | Def. N. | 26° 15' | S.S.W. | 1-553 | -0.050 | +0.004 | 1-507 | Table steady. | | | | | Def. S. | 28° 00' | S.S.W. | 1-538 | -0.050 | +0.004 | 1-492 | Table steady. | | | | | Def. N.S. | 47° 30' | S.S.W. | 1-516 | -0.050 | +0.007 | 1-473 | Table steady. | ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|--------|-------|-----------------|---------------------|-------------|------------|-----------|-------------|---------------------|------------------| | Feb. 11 | -67° 35' 39" 31' | Def. N. | 26° 35' 33" | N.E. | 1·534 | -0·016 | +0·004 | 1·522 | Very unsteady. | | | | Def. S. | 27° 55' 32" | N.E. | 1·544 | -0·016 | +0·004 | 1·532 | | | | | Def. N.S. | 47° 35' 31" | N.E. | 1·510 | -0·016 | +0·008 | 1·502 | | | | | Def. N. | 26° 12' 37" | S.S.E. | 1·556 | -0·049 | +0·003 | 1·510 | | | | | Def. S. | 28° 17' 37" | S.S.E. | 1·522 | -0·049 | +0·003 | 1·476 | Very unsteady. | | | | Def. N.S. | 47° 12' 37" | S.S.E. | 1·537 | -0·049 | +0·007 | 1·495 | | | | | Def. N. | 26° 22' 37" | E.N.E. | 1·547 | -0·025 | +0·003 | 1·525 | | | | | Def. S. | 28° 10' 36" | E.N.E. | 1·529 | -0·025 | +0·003 | 1·507 | | | | | Def. N.S. | 47° 42' 35" | E.N.E. | 1·504 | -0·025 | +0·007 | 1·486 | | | | | wt. 1 gr. | 14° 00' 32" | E.N.E. | 1·529 | -0·025 | +0·002 | 1·502 | Table steady. | | | | wt. 2 grs. | 28° 17' 32" | E.N.E. | 1·534 | -0·025 | +0·002 | 1·507 | | | | | wt. 2½ grs. | 37° 27' 32" | E.N.E. | 1·496 | -0·025 | +0·002 | 1·469 | | | Feb. 12 | -66° 45' 39" 23' | Def. N. | 27° 10' 37" | S. ¾ E. | 1·504 | -0·053 | +0·003 | 1·454 | Very unsteady. | | | | Def. S. | 28° 02' 37" | S. ¾ E. | 1·536 | -0·053 | +0·003 | 1·486 | | | | | Def. N. | 27° 34' 38" | N. by W. | 1·488 | -0·019 | +0·003 | 1·472 | | | | | Def. S. | 29° 12' 38" | N. by W. | 1·473 | -0·019 | +0·003 | 1·457 | Very unsteady. | | | | Def. N.S. | 48° 10' 38" | N. by W. | 1·473 | -0·019 | +0·006 | 1·460 | | | Feb. 13 | -67° 00' 40" 07' | Def. N. | 26° 52' 38" | S. by E. | 1·519 | -0·053 | +0·003 | 1·469 | Very unsteady. | | | | Def. S. | 28° 42' 37" | S. by E. | 1·500 | -0·053 | +0·003 | 1·450 | | | | | Def. N. | 28° 35' 39" | E. by S. | 1·431 | -0·053 | +0·003 | 1·399 | Very unsteady. | | | | Def. S. | 29° 47' 37" | E. by S. | 1·443 | -0·035 | +0·003 | 1·411 | | | | | Def. N.S. | 48° 15' 36" | E. by S. | 1·468 | -0·035 | +0·006 | 1·439 | | | Feb. 14 | -64° 52' 38" 37' | Def. N. | 29° 02' 44" | S.E. by E. ½ E. | 1·482 | -0·049 | +0·002 | 1·435 | Very unsteady. | | | | Def. N.S. | 48° 00' 45" | S.E. by E. ½ E. | 1·483 | -0·049 | +0·005 | 1·439 | | | Feb. 15 | -63° 22' 45" 35' | Def. N. | 27° 00' 42" | S.S.E. | 1·512 | -0·049 | +0·002 | 1·465 | | | | | Def. S. | 28° 37' 41" | S.S.E. | 1·505 | -0·049 | +0·002 | 1·458 | Table unsteady. | | | | Def. N.S. | 47° 52' 41" | S.S.E. | 1·491 | -0·049 | +0·006 | 1·448 | | | Feb. 16 | -62° 36' 51" 40' | Def. N. | 47° 54' 36" | E. | 1·490 | -0·031 | +0·007 | 1·466 | Very unsteady. | | | | Def. N.S. | 46° 45' 36" | E. | 1·526 | -0·031 | +0·003 | 1·498 | | | | | Def. S. | 29° 27' 34" | E. | 1·460 | -0·031 | +0·004 | 1·433 | | | Feb. 17 | -61° 25' 53" 38' | Def. N. | 27° 05' 40" | E.S.E. | 1·507 | -0·039 | +0·003 | 1·471 | | | | | Def. S. | 28° 32' 39" | E.S.E. | 1·510 | -0·039 | +0·003 | 1·474 | Unsteady. | | | | Def. N.S. | 47° 30' 38" | E.S.E. | 1·516 | -0·039 | +0·006 | 1·483 | | | Feb. 18 | -61° 17' 57" 28' | Def. N. | 25° 30' 41" | S.E. ½ E. | 1·595 | -0·044 | +0·002 | 1·553 | Table unsteady. | | | | Def. S. | 27° 30' 42" | S.E. ½ E. | 1·566 | -0·044 | +0·002 | 1·524 | | | | | Def. N.S. | 46° 45' 44" | S.E. ½ E. | 1·567 | -0·044 | +0·005 | 1·528 | | | Feb. 19 | -61° 00' 64" 03' | Def. N. | 25° 17' 37" | S.E. ½ S. | 1·607 | -0·050 | +0·003 | 1·560 | | | | | Def. S. | 26° 30' 36" | S.E. ½ S. | 1·622 | -0·050 | +0·004 | 1·576 | Table steady. | | | | Def. N.S. | 46° 47' 35" | S.E. ½ S. | 1·564 | -0·050 | +0·008 | 1·582 | | | Feb. 20 | -61° 36' 70" 46' | Def. N. | 24° 22' 40" | S.S.E. | 1·660 | -0·052 | +0·003 | 1·611 | Table unsteady. | | | | Def. S. | 25° 57' 39" | S.S.E. | 1·654 | -0·052 | +0·003 | 1·605 | | | | | Def. N.S. | 45° 42' 38" | S.S.E. | 1·640 | -0·052 | +0·007 | 1·595 | | | Mar. 1 | -62° 10' 72" 25' | Def. N. | 23° 10' 44" | S.S.E. | 1·731 | -0·058 | +0·002 | 1·681 | | | | | Def. S. | 25° 37' 44" | S.S.E. | 1·674 | -0·052 | +0·002 | 1·624 | | | | | Def. N.S. | 44° 50' 44" | S.S.E. | 1·705 | -0·052 | +0·005 | 1·658 | | | | | wt. 1 gr. | 11° 37' 44" | S.S.E. | 1·837 | -0·052 | +0·001 | 1·784* | Table steady. | | | | wt. 2 grs. | 25° 00' 43" | S.S.E. | 1·719 | -0·052 | +0·001 | 1·666 | | | | | wt. 2½ grs. | 32° 12' 43" | S.S.E. | 1·708 | -0·052 | +0·001 | 1·655 | | | | | Def. N. | 23° 50' 42" | S. | 1·693 | -0·056 | +0·002 | 1·639 | | | | | Def. S. | 25° 10' 42" | S. | 1·699 | -0·056 | +0·002 | 1·645 | | | | | Def. N.S. | 44° 45' 41" | S. | 1·710 | -0·056 | +0·006 | 1·660 | | | | | wt. 1 gr. | 11° 35' 39" | S. | 1·838 | -0·056 | +0·001 | 1·781* | | | | | wt. 2 grs. | 24° 47' 39" | S. | 1·733 | -0·056 | +0·001 | 1·676 | | | | | wt. 2½ grs. | 32° 00' 39" | S. | 1·718 | -0·056 | +0·001 | 1·661 | | * Not included in the mean; angle of deflection become too small. 3 H 2 ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|--------------------------| | 1845 Mar. 3. | -64°20' | 79°38' | Def. N. | 22°38' | s. by w. ½ w. | 1·763 | -0·055 | +0·04 | 1·712 | Table unsteady. | | | | | Def. S. | 24°17' | s. by w. ½ w. | 1·754 | -0·055 | +0·04 | 1·703 | | | | | | Def. N.S. | 44°12' | s. by w. ½ w. | 1·750 | -0·055 | +0·09 | 1·704 | | | | | | Def. N. | 23°02' | s.e. | 1·740 | -0·051 | +0·03 | 1·692 | | | | | | Def. S. | 24°20' | s.e. | 1·752 | -0·051 | +0·03 | 1·704 | | | | | | Def. N.S. | 44°40' | s.e. | 1·716 | -0·051 | +0·07 | 1·672 | | | | | | Def. N. | 22°40' | N.E. ½ N. | 1·761 | -0·025 | +0·04 | 1·740 | | | | | | Def. S. | 23°55' | N.E. ½ N. | 1·780 | -0·025 | +0·04 | 1·759 | | | | | | Def. N.S. | 44°50' | N.E. ½ N. | 1·705 | -0·025 | +0·08 | 1·688 | | | | | | Def. N. | 22°02' | s. by E. | 1·800 | -0·055 | +0·03 | 1·748 | | | | | | Def. S. | 23°05' | s. by E. | 1·831 | -0·055 | +0·03 | 1·779 | | | | | | Def. N.S. | 43°30' | s. by E. | 1·805 | -0·055 | +0·07 | 1·757 | | | | | | Def. N. | 22°00' | s.w. by s. | 1·801 | -0·054 | +0·04 | 1·751 | | | | | | Def. S. | 23°22' | s.w. by s. | 1·812 | -0·054 | +0·04 | 1·762 | | | | | | Def. N.S. | 43°37' | s.w. by s. | 1·800 | -0·054 | +0·08 | 1·754 | | | | | | Def. N. | 22°05' | E. | 1·795 | -0·042 | +0·04 | 1·757 | | | | | | Def. S. | 23°37' | E. | 1·796 | -0·042 | +0·04 | 1·758 | | | | | | Def. N.S. | 43°32' | E. | 1·804 | -0·042 | +0·08 | 1·770 | | | | | | wt. 1 gr. | 11°17' | E. | 1·890 | -0·045 | +0·02 | 1·843* | | | | | | wt. 2 grs. | 23°50' | E. | 1·801 | -0·045 | +0·02 | 1·754* | | | | | | wt. 2½ grs. | 29°05' | E. | 1·870 | -0·045 | +0·02 | 1·823* | | | | | | Def. N. | 22°17' | E. | 1·783 | -0·045 | +0·03 | 1·741 | | | | | | Def. S. | 23°55' | E. | 1·780 | -0·045 | +0·04 | 1·739 | | | | | | Def. N.S. | 43°40' | E. | 1·791 | -0·045 | +0·08 | 1·754 | | | | | | Def. N. | 20°57' | S.E. ½ S. | 1·867 | -0·055 | +0·04 | 1·816 | | | | | | Def. S. | 23°07' | S.E. ½ S. | 1·831 | -0·055 | +0·04 | 1·780 | | | | | | Def. N. | 21°05' | E. ½ S. | 1·810 | -0·047 | +0·04 | 1·767 | | | | | | Def. S. | 22°57' | E. ½ S. | 1·839 | -0·047 | +0·04 | 1·796 | | | | | | Def. N.S. | 43°45' | E. ½ S. | 1·785 | -0·047 | +0·09 | 1·747 | | | | | | Def. N. | 21°42' | E. ½ N. | 1·820 | -0·042 | +0·04 | 1·782 | | | | | | Def. S. | 23°32' | E. ½ N. | 1·804 | -0·042 | +0·04 | 1·766 | | | | | | Def. N.S. | 43°25' | E. ½ N. | 1·813 | -0·042 | +0·08 | 1·779 | | | | | | wt. 1 gr. | 11°20' | E. ½ N. | 1·884 | -0·042 | +0·03 | 1·839* | | | | | | wt. 2 grs. | 23°42' | E. ½ N. | 1·810 | -0·042 | +0·03 | 1·763 | | | | | | wt. 2½ grs. | 30°02' | E. ½ N. | 1·820 | -0·042 | +0·03 | 1·775 | | | | | | Def. N.S. | 41°05' | E. by s. | 2·006 | -0·047 | +0·09 | 1·968 | | | | | | Def. N. | 21°15' | E. by s. | 1·848 | -0·047 | +0·03 | 1·804 | | | | | | Def. S. | 22°57' | E. by s. | 1·839 | -0·047 | +0·03 | 1·795 | | | | | | Def. N.S. | 43°35' | E. by s. | 1·800 | -0·047 | +0·07 | 1·760 | | | | | | Def. N. | 21°15' | E. by N. | 1·848 | -0·042 | +0·04 | 1·810 | | | | | | Def. S. | 22°35' | E. by N. | 1·864 | -0·042 | +0·04 | 1·826 | | | | | | Def. N.S. | 43°00' | E. by N. | 1·845 | -0·042 | +0·08 | 1·811 | | | | | | Def. N. | 21°30' | N.E. | 1·832 | -0·036 | +0·04 | 1·800 | | | | | | Def. S. | 22°52' | N.E. | 1·844 | -0·036 | +0·04 | 1·812 | | | | | | Def. N.S. | 43°20' | N.E. | 1·819 | -0·036 | +0·08 | 1·791 | | | | | | Def. N. | 20°20' | S.E. | 1·912 | -0·054 | +0·04 | 1·862 | | | | | | Def. S. | 22°22' | S.E. | 1·878 | -0·054 | +0·04 | 1·828 | | | | | | Def. N. | 21°35' | E. | 1·826 | -0·045 | +0·04 | 1·785 | | | | | | Def. S. | 23°10' | E. | 1·830 | -0·045 | +0·04 | 1·789 | | | | | | Def. N. | 21°37' | N.N.E. ½ E. | 1·825 | -0·034 | +0·04 | 1·795 | | | | | | Def. S. | 22°40' | N.N.E. ½ E. | 1·858 | -0·034 | +0·04 | 1·828 | | | | | | Def. N.S. | 42°57' | N.N.E. ½ E. | 1·846 | -0·034 | +0·08 | 1·820 | | | | | | Def. S. | 23°20' | N.N.E. ½ E. | 1·816 | -0·034 | +0·04 | 1·786 | | | | | | Def. N.S. | 43°22' | N.N.E. ½ E. | 1·818 | -0·034 | +0·04 | 1·788 | | * Not included in the mean. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed. | Angle of deflection. | Thermometer. | Ship's head. | Intensity. | Corrections. | Corrected Intensity. | Remarks. | |------------|------|-------|------------------|----------------------|--------------|--------------|------------|---------------|----------------------|----------| | 1845. | | | Def. N. | 21° 20' 45" | N.E. by N. | 1·843 | -0·027 | +0·003 | 1·819 | | | Mar.20. | -49° | 111° 47' | Def. S. | 23 32 45 | N.E. by N. | 1·805 | -0·027 | +0·003 | 1·781 | | | | | | Def. N.S. | 43 15 45 | N.E. by N. | 1·825 | -0·027 | +0·006 | 1·804 | | | | | | wt. 1 gr. | 11 10 44 | N.E. by N. | 1·911 | -0·027 | -0·002 | 1·882 | 1·798 | | | | | wt. 2 grs. | 23 32 44 | N.E. by N. | 1·823 | -0·027 | -0·002 | 1·794 | | | | | | wt. 2½ grs. | 30 02 45 | N.E. by N. | 1·820 | -0·027 | -0·002 | 1·791 | | | 22. | -47° | 21 115 15 | Def. N. | 21 05 49 | E.N.E. | 1·857 | -0·035 | +0·002 | 1·824 | | | | | | Def. S. | 22 10 49 | E.N.E. | 1·892 | -0·035 | +0·002 | 1·859 | 1·825 | | | | | Def. N.S. | 43 20 48 | E.N.E. | 1·821 | -0·035 | +0·005 | 1·791 | | | 25. | -43° | 20 116 52 | Def. N. | 23 27* 51 | N. ½ E. | 1·712 | -0·025 | +0·002 | 1·689 | | | | | | Def. S. | 23 35 51 | N. ½ E. | 1·799 | -0·025 | +0·002 | 1·776 | | | | | | Def. N.S. | 43 45 51 | N. ½ E. | 1·785 | -0·025 | +0·003 | 1·763 | | | | | | wt. 1 gr. | 12 07 50 | N. ½ E. | 1·764 | -0·025 | -0·001 | 1·738 | | | | | | wt. 2 grs. | 23 32 50 | N. ½ E. | 1·823 | -0·025 | -0·001 | 1·797 | | | | | | wt. 2½ grs. | 31 17 50 | N. ½ E. | 1·752 | -0·025 | -0·001 | 1·726 | | | 26. | -41° | 18 116 09 | Def. N. | 22 30 54 | N. by W. | 1·771 | -0·020 | +0·001 | 1·752 | | | | | | Def. S. | 23 57 54 | N. by W. | 1·776 | -0·020 | +0·001 | 1·757 | | | | | | Def. N.S. | 44 15 54 | N. by W. | 1·747 | -0·020 | +0·002 | 1·729 | | | 27. | -38° | 52 116 15 | Def. N. | 22 37 58 | N. by W. | 1·765 | -0·012 | -0·000 | 1·753 | | | | | | Def. S. | 23 52 58 | N. by W. | 1·770 | -0·012 | -0·000 | 1·758 | | | | | | Def. N.S. | 44 40 60 | N. by W. | 1·716 | -0·012 | -0·000 | 1·704 | | | 28. | -37° | 03 116 57 | Def. N. | 23 25 59 | N. by E. | 1·718 | -0·012 | -0·000 | 1·706 | | | | | | Def. S. | 24 45 60 | N. by E. | 1·725 | -0·012 | -0·000 | 1·713 | | | | | | Def. N.S. | 44 30 61 | N. by E. | 1·728 | -0·012 | -0·000 | 1·716 | | | | | | wt. 1 gr. | 12 45 62 | N. by E. | 1·678 | -0·012 | -0·000 | 1·666 | | | | | | wt. 2 grs. | 25 40 62 | N. by E. | 1·678 | -0·012 | -0·000 | 1·666 | | | | | | wt. 2½ grs. | 32 07 63 | N. by E. | 1·714 | -0·012 | -0·000 | 1·702 | | | 29. | -36° | 12 116 50 | Def. N. | 23 40 66 | N.N.E. | 1·701 | -0·012 | -0·001 | 1·688 | | | | | | Def. S. | 25 37 67 | N.N.E. | 1·673 | -0·012 | -0·001 | 1·660 | | | | | | Def. N.S. | 45 05 68 | N.N.E. | 1·685 | -0·012 | -0·003 | 1·670 | | | 30. | -35° | 18 117 07 | Def. N. | 23 22 66 | N.E. ½ E. | 1·719 | -0·012 | -0·001 | 1·706 | | | | | | Def. S. | 24 45 66 | N.E. ½ E. | 1·725 | -0·012 | -0·001 | 1·712 | | | | | | Def. N.S. | 44 52 66 | N.E. ½ E. | 1·701 | -0·012 | -0·002 | 1·687 | | | April 7. | -35° | 02 117 56 | Def. N. | 23 50 68 | | 1·692 | -0·001 | -0·001 | 1·691 | | | | | | Def. S. | 25 18 68 | | 1·692 | -0·001 | -0·001 | 1·691 | | | | | | Def. N.S. | 45 06 69 | | 1·685 | -0·001 | -0·001 | 1·684 | | | | | | wt. 1 gr. | 12 22 69 | | 1·726 | -0·001 | -0·001 | 1·727† | | | | | | wt. 2 grs. | 25 24 69 | | 1·695 | -0·001 | -0·001 | 1·696 | | | | | | wt. 2½ grs. | 32 52 68 | | 1·676 | -0·001 | -0·001 | 1·677 | | | 11. | King George's Sound, West Australia. | Def. N. | 23 42 82 | | 1·700 | -0·002 | -0·002 | 1·698 | | | | | | Def. S. | 25 12 82 | | 1·697 | -0·002 | -0·002 | 1·695 | | | | | | Def. N.S. | 44 59 83 | | 1·692 | -0·005 | -0·005 | 1·687 | | | | | | wt. 1 gr. | 12 37 84 | | 1·692 | +0·001 | +0·001 | 1·693 | | | | | | wt. 2 grs. | 25 30 84 | | 1·689 | +0·001 | +0·001 | 1·690 | | | | | | wt. 2½ grs. | 33 01 85 | | 1·670 | +0·003 | +0·003 | 1·672 | | | 19. | At Anchor in the Sound. Swinging the ship for local attraction. | Def. N.S. | 44 09 54 | S.S.W. | 1·754 | -0·056 | +0·001 | 1·699 | | | | | | Def. N.S. | 44 20 54 | S.W. | 1·740 | -0·051 | +0·001 | 1·690 | | | | | | Def. N.S. | 44 30 54 | W.S.W. | 1·728 | -0·041 | +0·001 | 1·688 | | | | | | Def. N.S. | 44 44 54 | W. | 1·710 | -0·032 | +0·001 | 1·679 | | | | | | Def. N.S. | 44 50 54 | W.N.W. | 1·702 | -0·022 | +0·001 | 1·681 | | | | | | Def. N.S. | 45 04 54 | N.W. | 1·687 | -0·012 | +0·001 | 1·676 | | | | | | Def. N.S. | 45 01 54 | N.N.W. | 1·691 | -0·012 | +0·001 | 1·680 | | | | | | Def. N.S. | 44 59 57 | N. | 1·692 | -0·012 | +0·001 | 1·681 | | | | | | Def. N.S. | 45 03 58 | N.N.E. | 1·688 | -0·012 | -0·000 | 1·676 | | * The degree should probably be 22°; not included. † Not included in the mean. The observations were made on the same spot where Captains Flinders and Fitzroy had previously observed. The table was very steady during these observations. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |----------|------|-------|-----------------|---------------------|-------------|------------|-----------|-------------|---------------------|---------| | Apr.19 | | | Def. N.S. | 45° 01' | N.E. | 1·691 | -0·012 | -0·000 | 1·679 | 1·683 | | | | | Def. N.S. | 44° 49' | E.N.E. | 1·702 | -0·022 | -0·000 | 1·680 | | | | | | Def. N.S. | 44° 47' | E. | 1·705 | -0·032 | -0·000 | 1·673 | | | | | | Def. N.S. | 44° 33' | E.S.E. | 1·723 | -0·041 | -0·001 | 1·681 | | | | | | Def. N.S. | 44° 20' | S.E. | 1·740 | -0·051 | -0·001 | 1·688 | | | | | | Def. N.S. | 44° 14' | S.S.E. | 1·748 | -0·056 | -0·001 | 1·691 | | | | | | Def. N.S. | 44° 11' | S. | 1·751 | -0·061 | -0·001 | 1·689 | | | | | | Def. N.S. | 23° 57' | N.W. | 1·686 | -0·012 | -0·000 | 1·674 | | | | | | Def. S. | 45° 00' | N.W. | 1·692 | -0·012 | -0·001 | 1·670 | 1·688 | | | | | Def. N. | 24° 40' | N.W. by n. | 1·643 | -0·012 | -0·001 | 1·630 | | | | | | Def. N.S. | 25° 37' | N.W. by n. | 1·674 | -0·012 | -0·001 | 1·661 | 1·641 | | | | | Def. N.S. | 45° 37' | N.W. by n. | 1·647 | -0·012 | -0·002 | 1·633 | | | | | | Def. N. | 25° 02' | N.W. by n. | 1·623 | -0·008 | -0·001 | 1·614 | | | | | | Def. S. | 26° 17' | N.W. by n. | 1·634 | -0·008 | -0·001 | 1·625 | 1·613 | | | | | Def. N.S. | 46° 05' | N.W. by n. | 1·612 | -0·008 | -0·003 | 1·601 | | | | | | Def. N. | 25° 07' | W.N.W. | 1·619 | -0·016 | -0·002 | 1·601 | | | | | | Def. S. | 27° 32' | W.N.W. | 1·566 | -0·016 | -0·002 | 1·548 | 1·553 | | | | | Def. N.S. | 47° 15' | W.N.W. | 1·531 | -0·016 | -0·004 | 1·511 | | | | | | Def. N. | 27° 17' | N.by w.½ w.| 1·497 | -0·000 | -0·001 | 1·496 | | | | | | Def. S. | 29° 02' | N.by w.½ w.| 1·482 | -0·000 | -0·001 | 1·481 | 1·490 | | | | | Def. N.S. | 47° 47' | N.by w.½ w.| 1·497 | -0·000 | -0·003 | 1·494 | | | | | | Def. N. | 27° 30' | N.W. | 1·486 | -0·005 | -0·001 | 1·480 | | | | | | Def. S. | 29° 10' | N.W. | 1·474 | -0·005 | -0·001 | 1·468 | 1·470 | | | | | Def. N.S. | 48° 12' | N.W. | 1·471 | -0·005 | -0·004 | 1·462 | | | | | | Def. N. | 29° 07' | W. | 1·396 | -0·021 | -0·001 | 1·374 | | | | | | Def. S. | 31° 00' | W. | 1·381 | -0·021 | -0·001 | 1·359 | 1·367 | | | | | Def. N.S. | 49° 30' | W. | 1·393 | -0·021 | -0·003 | 1·369 | | | | | | Def. N. | 29° 02' | W.½ N. | 1·410 | -0·017 | -0·001 | 1·392 | | | | | | Def. S. | 30° 50' | W. | 1·390 | -0·017 | -0·001 | 1·372 | 1·379 | | | | | Def. N.S. | 49° 32' | W.½ N. | 1·392 | -0·017 | -0·003 | 1·372 | | | | | | Def. N. | 29° 40' | W.½ N. | 1·381 | -0·017 | -0·001 | 1·363 | | | | | | Def. S. | 31° 02' | W.½ N. | 1·380 | -0·017 | -0·001 | 1·362 | | | | | | Def. N.S. | 50° 15' | W.½ N. | 1·350 | -0·017 | -0·004 | 1·329 | | | | | | wt. 1 gr. | 15° 02' | W.½ N. | 1·423 | -0·017 | +0·001 | 1·407 | | | | | | wt. 2 grs. | 31° 47' | W.½ N. | 1·380 | -0·017 | +0·001 | 1·364 | | | | | | wt. 2½ grs. | 41° 10' | W.½ N. | 1·383 | -0·017 | +0·001 | 1·367 | | | | | | Def. N. | 30° 57' | N.W. | 1·320 | +0·008 | -0·001 | 1·327 | | | | | | Def. S. | 32° 25' | N.W. | 1·315 | +0·008 | -0·002 | 1·321 | 1·324 | | | | | Def. N.S. | 60° 50' | N.W. | 1·321 | +0·008 | -0·005 | 1·324 | | | | | | Def. N. | 30° 45' | N.W. | 1·329 | +0·008 | -0·001 | 1·336 | | | | | | Def. S. | 32° 15' | N.W. | 1·332 | +0·008 | -0·001 | 1·329 | 1·326 | | | | | Def. N.S. | 51° 10' | N.W. | 1·308 | +0·008 | -0·004 | 1·312 | | | | | | Def. N. | 31° 45' | N.W.by w. | 1·279 | +0·004 | -0·001 | 1·282 | | | | | | Def. S. | 32° 20' | N.W.by w. | 1·318 | +0·004 | -0·001 | 1·321 | | | | | | Def. N.S. | 51° 25' | N.W.by w. | 1·292 | +0·004 | -0·004 | 1·292 | | | | | | Def. N. | 32° 00' | N.W.by w. | 1·268 | +0·004 | -0·002 | 1·270 | | | | | | Def. S. | 32° 37' | N.W.by w. | 1·306 | +0·004 | -0·001 | 1·309 | | | | | | Def. N.S. | 51° 27' | N.W.by w. | 1·291 | +0·004 | -0·004 | 1·291 | | | | | | Def. N. | 31° 42' | W.½ N. | 1·286 | -0·014 | -0·001 | 1·271 | | | | | | Def. S. | 33° 02' | W.½ N. | 1·286 | -0·014 | -0·001 | 1·271 | | | | | | Def. N.S. | 51° 50' | W.½ N. | 1·270 | -0·014 | -0·004 | 1·252 | | **Remarks:** - Intensity by Def. N.S. on shore 1°065. - Table unsteady. - Very unsteady, heavy swell. - Very unsteady, much motion. - Table steady, little motion. - Table steady, no swell. - Very unsteady, heavy westerly swell. **W. Burdon, Esq., R.N., observer.** ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|---------| | **1845.** | | | | | | | | | | | | May 10. | -20° | 26' | Def. N. | 31° 37' | 77 | w. ½ N. | 1·288 | -0·014 | 1·273 | | | | | | Def. S. | 33° 15' | 78 | w. ½ N. | 1·277 | -0·014 | 1·262 | | | | | | Def. N.S. | 52° 10' | 80 | w. ½ N. | 1·260 | -0·014 | 1·241 | | | | | | Def. N. | 31° 35' | 75 | w. ½ N. | 1·289 | -0·016 | 1·272 | | | | | | Def. S. | 33° 27' | 75 | w. ½ N. | 1·269 | -0·016 | 1·252 | | | | | | Def. N.S. | 52° 07' | 74 | w. ½ N. | 1·260 | -0·016 | 1·241 | | | | | | Def. N. | 31° 52' | 77 | w. ½ N. | 1·274 | -0·016 | 1·257 | | | | | | Def. S. | 33° 37' | 77 | w. ¼ N. | 1·262 | -0·016 | 1·245 | | | | | | Def. N.S. | 52° 07' | 78 | w. ¼ N. | 1·260 | -0·016 | 1·239 | | | | | | Def. N. | 31° 52' | 78 | w. ¼ N. | 1·274 | -0·016 | 1·256 | | | | | | Def. S. | 33° 40' | 77 | w. ½ N. | 1·260 | -0·016 | 1·242 | | | | | | Def. N.S. | 52° 00' | 78 | w. ½ N. | 1·262 | -0·016 | 1·241 | | | | | | Def. N. | 52° 17' | 84 | W. | 1·249 | -0·018 | 1·225 | | | | | | Def. N.S. | 52° 20' | 86 | W.N.W. | 1·248 | -0·004 | 1·238 | | | | | | Def. N.S. | 52° 32' | 88 | N.W. | 1·239 | +0·008 | 1·241 | | | | | | Def. N.S. | 52° 50' | 91 | N.N.W. | 1·226 | +0·006 | 1·224 | | | | | | Def. N.S. | 51° 20' | 80 | S. | 1·296 | -0·046 | 1·245 | | | | | | Def. N.S. | 51° 22' | 82 | S.S.W. | 1·294 | -0·043 | 1·246 | | | | | | Def. N.S. | 51° 30' | 82 | S.W. | 1·287 | -0·037 | 1·245 | | | | | | Def. N.S. | 51° 55' | 83 | W.S.W. | 1·267 | -0·026 | 1·236 | | | | | | Def. N.S. | 52° 25' | 82 | N.N.E. | 1·242 | +0·006 | 1·243 | | | | | | Def. N.S. | 52° 42' | 77 | W. | 1·227 | -0·018 | 1·205 | | | | | | Def. N.S. | 52° 15' | 77 | N.W. | 1·250 | +0·008 | 1·254 | | | | | | Def. N.S. | 52° 32' | 77 | N. | 1·239 | +0·008 | 1·243 | | | | | | Def. N.S. | 52° 22' | 77 | N.E. | 1·247 | +0·008 | 1·251 | | | | | | Def. N.S. | 52° 07' | 78 | E. | 1·260 | -0·018 | 1·237 | | | | | | Def. N.S. | 51° 45' | 77 | S.E. | 1·275 | -0·037 | 1·234 | | | | | | Def. N. | 32° 27' | 76 | w. ½ N. | 1·249 | -0·016 | 1·232 | | | | | | Def. S. | 33° 52' | 76 | w. ½ N. | 1·252 | -0·016 | 1·235 | | | | | | Def. N.S. | 52° 50' | 76 | w. ½ N. | 1·226 | -0·016 | 1·206 | | | | | | Def. N. | 33° 20' | 76 | w. ½ N. | 1·212 | -0·016 | 1·195 | | | | | | Def. S. | 33° 37' | 76 | w. ½ N. | 1·262 | -0·016 | 1·245 | | | | | | Def. N.S. | 52° 30' | 75 | w. ½ N. | 1·238 | -0·016 | 1·218 | | | | | | Def. N. | 32° 45' | 78 | w. ½ N. | 1·236 | -0·017 | 1·217 | | | | | | Def. S. | 34° 05' | 78 | w. ½ N. | 1·200 | -0·017 | 1·181 | | | | | | Def. N.S. | 52° 55' | 78 | w. ½ N. | 1·222 | -0·017 | 1·200 | | | | | | Def. N. | 32° 57' | 80 | W.S.W. | 1·227 | -0·026 | 1·199 | | | | | | Def. S. | 34° 37' | 80 | W.S.W. | 1·221 | -0·026 | 1·193 | | | | | | Def. N.S. | 53° 10' | 83 | W.S.W. | 1·212 | -0·026 | 1·181 | | | | | | Def. N. | 33° 12' | 75 | N.W. by n. | 1·217 | -0·001 | 1·215 | | | | | | Def. S. | 34° 45' | 76 | N.W. by n. | 1·215 | -0·001 | 1·213 | | | | | | Def. N.S. | 53° 10' | 75 | N.W. by n. | 1·212 | -0·001 | 1·207 | | | | | | wt. 1 gr. | 18° 00' | 75 | N.W. by n. | 1·197 | -0·001 | 1·197 | | | | | | wt. 2 grs. | 37° 52' | 75 | N.W. by n. | 1·183 | -0·001 | 1·183 | | | | | | wt. 2½ grs. | 49° 32' | 75 | N.W. by n. | 1·196 | -0·001 | 1·196 | | | | | | Def. N. | 33° 37' | 75 | N.W. by n. | 1·202 | -0·001 | 1·200 | | | | | | Def. S. | 34° 45' | 76 | N.W. by n. | 1·215 | -0·001 | 1·213 | | | | | | Def. N.S. | 53° 20' | 75 | N.W. by n. | 1·204 | -0·001 | 1·199 | | | | | | Def. N. | 33° 25' | 76 | w. by n. | 1·200 | -0·013 | 1·186 | | | | | | Def. S. | 34° 45' | 77 | w. by n. | 1·215 | -0·013 | 1·201 | | | | | | Def. N.S. | 53° 05' | 79 | w. by n. | 1·214 | -0·013 | 1·196 | | | | | | Def. N. | 33° 32' | 81 | w. by n. | 1·205 | -0·013 | 1·190 | | | | | | Def. S. | 34° 02' | 81 | w. by n. | 1·243 | -0·013 | 1·228 | | | | | | Def. N.S. | 52° 55' | 81 | w. by n. | 1·223 | -0·013 | 1·205 | | **Remarks:** - Very unsteady. - Table very unsteady; calm. - Table steady. - Table steady, nearly calm. **W. Burdon, Esq., R.N., observer.** ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|---------| | **1845.** | | | | | | | | | | | | May 21. | -21° 02' 66° 02' | Def. N. | 33° 40' 76° w. by n. | 1·201 | -0·013 | 1·187 | Table steady. | | | | | Def. S. | 34° 40' 76° w. by n. | 1·216 | -0·013 | 1·202 | | | | | | Def. N.S. | 53° 15' 76° w. by n. | 1·201 | -0·013 | 1·184 | | | | | | wt. 1 gr. | 18° 22' 76° w. by n. | 1·175 | -0·013 | 1·163 | | | | | | wt. 2 grs. | 37° 37' 76° w. by n. | 1·191 | -0·013 | 1·179 | | | | | | wt. 2½ grs. | 50° 20' 76° w. by n. | 1·182 | -0·013 | 1·170 | | | | | | Def. N. | 33° 47' 77° w. by n. | 1·194 | -0·013 | 1·180 | | | | | | Def. S. | 35° 30' 77° w. by n. | 1·185 | -0·013 | 1·171 | Very unsteady. | | | | | Def. N.S. | 53° 55' 78° w. by n. | 1·179 | -0·013 | 1·162 | | | | | | Def. N. | 34° 58' 81° | 1·147 | -0·002 | 1·145 | | | | | | Def. S. | 35° 52' 81° | 1·170 | -0·002 | 1·168 | | | | | | Def. N.S. | 55° 32*° 81° Observed on shore. | 1·115 | -0·004 | 1·111* | | | | | | wt. 1 gr. | 19° 01' 81° | 1·135 | +0·001 | 1·136 | | | | | | wt. 2 grs. | 38° 12' 81° | 1·175 | +0·001 | 1·176 | | | | | Port Louis, Mauritius. | | | | | | | | | | | Def. N. | 33° 27' 80° w.s.w. ½ w. | 1·208 | -0·024 | 1·182 | | | | | | Def. S. | 34° 40' 82° w.s.w. ½ w. | 1·219 | -0·024 | 1·193 | | | | | | Def. N.S. | 53° 37' 82° w.s.w. ½ w. | 1·192 | -0·024 | 1·163 | | | June 2. | -26° 25' 49° 12' | Def. N. | 34° 27' 79° n.w. by w. | 1·168 | -0·005 | 1·161 | | | | | | Def. S. | 35° 47' 79° n.w. by w. | 1·173 | -0·005 | 1·166 | | | | | | Def. N.S. | 54° 22' 79° n.w. by w. | 1·161 | -0·005 | 1·152 | | | | | | Def. N. | 34° 45' 68° w. by s. | 1·156 | -0·024 | 1·131 | | | | | | Def. S. | 36° 20' 68° w. by s. | 1·152 | -0·024 | 1·127 | | | | | | Def. N.S. | 54° 30' 68° w. by s. | 1·155 | -0·024 | 1·130 | | | | | | Def. N. | 34° 55' 74° w. | 1·150 | -0·020 | 1·129 | | | | | | Def. S. | 36° 30' 74° w. | 1·145 | -0·020 | 1·124 | | | | | | Def. N.S. | 54° 45' 76° w. | 1·145 | -0·020 | 1·122 | | | | | | Def. N. | 35° 47' 73° w.N.W. | 1·116 | -0·009 | 1·106 | | | | | | Def. S. | 36° 55' 76° w.N.W. | 1·129 | -0·009 | 1·119 | | | | | | Def. N.S. | 54° 55' 78° w.N.W. | 1·139 | -0·009 | 1·127 | | | | | | Def. N. | 34° 47' 73° w. ½ N. | 1·156 | -0·017 | 1·138 | | | | | | Def. S. | 36° 40' 74° w. ½ N. | 1·138 | -0·017 | 1·128 | | | | | | Def. N.S. | 54° 47' 74° w. ½ N. | 1·145 | -0·017 | 1·125 | | | | | | Def. N. | 35° 42' 72° w. | 1·120 | -0·020 | 1·099 | | | | | | Def. S. | 37° 47' 76° w. | 1·095 | -0·020 | 1·074 | | | | | | Def. N.S. | 55° 10' 78° w. | 1·128 | -0·020 | 1·104 | | | | | | wt. 1 gr. | 19° 45' 80° w. | 1·100 | -0·020 | 1·082 | | | | | | wt. 2 grs. | 40° 30' 80° w. | 1·118 | -0·020 | 1·100 | | | | | | wt. 2½ grs. | 53° 57' 82° w. | 1·125 | -0·020 | 1·107 | | | | | | Def. N. | 36° 17' 66° w.N.W. | 1·098 | -0·009 | 1·088 | | | | | | Def. S. | 37° 40' 66° w.N.W. | 1·100 | -0·009 | 1·090 | | | | | | Def. N.S. | 56° 15' 66° w.N.W. | 1·086 | -0·009 | 1·076 | | | | | | Def. N. | 36° 27' 65° w.by s. ½ s. | 1·093 | -0·026 | 1·066 | | | | | | Def. S. | 37° 52' 65° w.by s. ½ s. | 1·093 | -0·026 | 1·066 | | | | | | Def. N.S. | 56° 32' 67° w.by s. ½ s. | 1·078 | -0·026 | 1·051 | | | | | | Def. N. | 36° 57' 71° w. | 1·075 | -0·020 | 1·054 | | | | | | Def. S. | 38° 35' 72° w. | 1·067 | -0·020 | 1·046 | | | | | | Def. N.S. | 56° 57' 73° w. | 1·062 | -0·020 | 1·039 | | | | | | Def. N. | 36° 40' 74° w. ½ N. | 1·085 | -0·014 | 1·070 | | | | | | Def. S. | 38° 42' 76° w. ½ N. | 1·063 | -0·014 | 1·048 | | | | | | Def. N.S. | 56° 47' 78° w. ½ N. | 1·067 | -0·014 | 1·049 | | | | | | wt. 1 gr. | 19° 47' 80° w. ½ N. | 1·092 | -0·014 | 1·079 | | | | | | wt. 2 grs. | 45° 02' 80° w. ½ N. | 1·027 | -0·014 | 1·014+ | | | | | | wt. 2½ grs. | 58° 57' 82° w. ½ N. | 1·063 | -0·014 | 1·050 | | * Probably the degree is erroneous; the result is not included in the mean. † Not included. ## Observations of the Magnetic Force. (Continued.) | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity | Corrections | Corrected Intensity | Remarks | |------------|------|-------|-----------------|---------------------|-------------|-------------|-----------|-------------|---------------------|--------------------------| | 1845. | | | | | | | | | | | | June 16 | -35° | 46' | Def. N. | 38° 06' 75'' | w. by n. | 1·042 | -0·012 | -0·001 | 1·029 | Table steady. | | | | | Def. S. | 39° 17' 77'' | w. by n. | 1·043 | -0·012 | -0·001 | 1·030 | | | | | | Def. N.S. | 57° 02' 78'' | w. by n. | 1·057 | -0·012 | -0·004 | 1·041 | | | 17. | -35° | 36' | Def. N. | 38° 45' 67'' | W.N.W. | 1·020 | -0·007 | -0·001 | 1·012 | Table steady. | | | | | Def. S. | 39° 47' 67'' | W.N.W. | 1·026 | -0·007 | -0·001 | 1·018 | | | | | | Def. N.S. | 57° 12' 67'' | W.N.W. | 1·053 | -0·007 | -0·001 | 1·045 | | | 18. | -35° | 07' | Def. N. | 38° 22' 64'' | w. by s. | 1·031 | -0·019 | -0·000 | 1·012 | | | | | | Def. S. | 39° 50' 63'' | w. by s. | 1·024 | -0·019 | -0·000 | 1·005 | Table steady, nearly calm. | | | | | Def. N.S. | 57° 30' 63'' | w. by s. | 1·042 | -0·019 | -0·001 | 1·022 | | | 23. | -34° | 12' | Def. N.S. | 57° 01' 62'' | S. | 1·060 | -0·040 | -0·000 | 1·020 | | | | | | Def. N.S. | 57° 08' 66'' | S.S.W. | 1·056 | -0·037 | -0·001 | 1·018 | | | | | | Def. N.S. | 57° 29' 68'' | S.W. | 1·042 | -0·031 | -0·001 | 1·010 | | | | | | Def. N.S. | 57° 52' 68'' | W.S.W. | 1·030 | -0·022 | -0·001 | 1·007 | | | | | | Def. N.S. | 58° 07' 70'' | W. | 1·021 | -0·014 | -0·002 | 1·005 | | | | | | Def. N.S. | 58° 11' 70'' | W.N.W. | 1·019 | -0·003 | -0·002 | 1·014 | | | | | | Def. N.S. | 58° 07' 82'' | N.W. | 1·020 | -0·002 | -0·004 | 1·014 | | | | | | Def. N.S. | 58° 16' 82'' | N.N.W. | 1·018 | -0·000 | -0·004 | 1·014 | | | | | | Def. N.S. | 58° 09' 83'' | N. | 1·020 | +0·002 | -0·005 | 1·017 | Swinging ship for local attraction. | | | | | Def. N.S. | 58° 10' 84'' | N.N.E. | 1·020 | -0·000 | -0·005 | 1·015 | | | | | | Def. N.S. | 58° 09' 85'' | N.E. | 1·020 | -0·002 | -0·005 | 1·013 | | | | | | Def. N.S. | 58° 07' 85'' | E.N.E. | 1·021 | -0·003 | -0·005 | 1·013 | | | | | | Def. N.S. | 57° 58' 86'' | E. | 1·026 | -0·014 | -0·005 | 1·007 | | | | | | Def. N.S. | 57° 53' 87'' | E.S.E. | 1·030 | -0·022 | -0·005 | 1·003 | | | | | | Def. N.S. | 57° 30' 88'' | S.E. | 1·042 | -0·031 | -0·006 | 1·005 | | | | | | Def. N.S. | 57° 10' 90'' | S.S.E. | 1·055 | -0·037 | -0·006 | 1·012 | | | | | | Def. N.S. | 58° 08' 68'' | On shore. | 1·021 | ......... | -0·001 | 1·020 | In the Dock Yard. | | | | | Def. N. | 39° 31' 59'' | | 0·992 | ......... | 0·992 | 0·992 | | | | | | Def. S. | 40° 39' 61'' | | 1·000 | ......... | 1·000 | 1·000 | | | | | | Def. N.S. | 58° 16' 62'' | | 1·016 | ......... | 1·016 | 1·016 | | | | | | wt. 1 gr. | 21° 38' 63'' | | 1·004 | ......... | 1·004 | 1·004 | | | | | | wt. 2 grs. | 46° 31' 64'' | | 1·001 | ......... | 1·001 | 1·001 | | | | | | wt. 2½ grs. | 65° 30' 65'' | | Observed | 0·999 | 0·999 | 0·999 | | | | | | Def. N. | 39° 22' 59'' | | 0·997 | ......... | 0·997 | 0·997 | | | | | | Def. S. | 40° 39' 60'' | | 1·000 | ......... | 1·000 | 1·000 | | | | | | Def. N.S. | 58° 21' 61'' | | 1·013 | ......... | 1·013 | 1·013 | | | | | | wt. 1 gr. | 22° 06' 63'' | | 0·986 | ......... | 0·986 | 0·986 | | | | | | wt. 2 grs. | 46° 21' 64'' | | 1·004 | ......... | 1·004 | 1·004 | | | | | | wt. 2½ grs. | 65° 30' 64'' | | 0·999 | ......... | 0·999 | 0·999 | | July 2. Magnetic Observatory, Cape of Good Hope. MDCCCXLVI. General Table of the Declinations observed on board Her Majesty's hired Bark "Pagoda." | Date | Lat. | Long. | No. of observations | Declination | |------|------|-------|---------------------|-------------| | Jan. | | | | | | 10 | -34° 42' | 17° 36' | 4 | +29° 51' | | 11 | -33° 26' | 15° 08' | 4 | +28° 39' | | 12 | -33° 17' | 14° 00' | 3 | +27° 15' | | 13 | -33° 10' | 13° 25' | 3 | +25° 40' | | 14 | -33° 43' | 14° 25' | 1 | +25° 09' | | 15 | -39° 18' | 14° 28' | 11 | +28° 20' | | 16 | -40° 15' | 14° 35' | 11 | +27° 40' | | 17 | -44° 45' | 13° 19' | 4 | +26° 34' | | 18 | -46° 24' | 13° 34' | 3 | +25° 54' | | 19 | -44° 27' | 10° 51' | 4 | +24° 50' | | 20 | -50° 45' | 10° 18' | 8 | +23° 55' | | 21 | -51° 47' | 9° 34' | 17 | +22° 37' | | 22 | -52° 56' | 7° 53' | 4 | +23° 46' | | 23 | -53° 52' | 6° 12' | 12 | +21° 34' | | 24 | -55° 29' | 5° 54' | 3 | +20° 23' | | 25 | -59° 02' | 4° 09' | 4 | +17° 30' | | 26 | -61° 12' | 9° 30' | 10 | +30° 29' | | Feb. | | | | | | 1 | -62° 03' | 12° 45' | 4 | +22° 07' | | 2 | -61° 54' | 16° 40' | 8 | +23° 11' | | 3 | -61° 49' | 19° 13' | 27 | +26° 16' | | 4 | -62° 05' | 20° 58' | 9 | +28° 05' | | 5 | -63° 18' | 21° 10' | 6 | +28° 56' | | 6 | -64° 25' | 25° 05' | 9 | +30° 24' | | 7 | -65° 43' | 28° 33' | 11 | +31° 37' | | 8 | -66° 26' | 37° 25' | 3 | +35° 39' | | 9 | -66° 55' | 38° 32' | 5 | +37° 43' | | 10 | -67° 34' | 39° 41' | 7 | +38° 13' | | 11 | -66° 41' | 39° 22' | 3 | +37° 18' | | 12 | -67° 06' | 40° 03' | 5 | +36° 59' | | 13 | -67° 01' | 40° 30' | 2 | +37° 12' | | 14 | -64° 52' | 38° 37' | 5 | +36° 38' | | 15 | -64° 52' | 40° 12' | 6 | +36° 54' | | 16 | -64° 22' | 40° 49' | 2 | +36° 32' | | 17 | -63° 57' | 41° 37' | 3 | +37° 34' | | 18 | -63° 32' | 45° 31' | 6 | +39° 39' | | 19 | -63° 37' | 47° 01' | 7 | +40° 03' | | 20 | -63° 43' | 49° 29' | 2 | +39° 21' | | 21 | -61° 33' | 53° 40' | 6 | +40° 30' | | 22 | -61° 18' | 57° 41' | 6 | +41° 57' | | 23 | -61° 04' | 63° 45' | 4 | +45° 17' | | 24 | -61° 43' | 69° 36' | 1 | +45° 51' | | March| | | | | | 1 | -62° 10' | 72° 25' | 7 | +46° 01' | | 2 | -62° 46' | 76° 30' | 11 | +50° 35' | | 3 | -63° 05' | 80° 20' | 1 | +52° 17' | | 4 | -61° 41' | 85° 20' | 7 | +47° 19' | | 5 | -60° 50' | 87° 41' | 3 | +47° 47' | | 6 | -61° 23' | 91° 26' | 10 | +49° 28' | | 7 | -61° 16' | 91° 43' | 7 | +49° 02' | | 8 | -60° 46' | 92° 20' | 6 | +48° 01' | | 9 | -60° 03' | 95° 15' | 4 | +44° 53' | | 10 | -59° 22' | 100° 31' | 7 | +41° 02' | | 11 | -58° 31' | 98° 59' | 1 | +39° 50' | | 12 | -58° 30' | 98° 32' | 3 | +40° 37' | | 13 | -56° 53' | 101° 15' | 2 | +37° 37' | | 14 | -55° 42' | 103° 15' | 3 | +32° 54' | | 15 | -54° 45' | 106° 17' | 6 | +29° 24' | | 16 | -54° 05' | 108° 15' | 2 | +26° 34' | | 17 | -53° 12' | 110° 24' | 6 | +21° 52' | | 18 | -49° 05' | 112° 47' | 10 | +17° 09' | | 19 | -46° 32' | 115° 54' | 1 | +12° 02' | | 20 | -44° 59' | 116° 53' | 2 | +9° 43' | | 21 | -43° 41' | 116° 57' | 6 | +7° 04' | | 22 | -41° 02' | 116° 42' | 4 | +4° 10' | | 23 | -38° 40' | 116° 17' | 4 | +6° 56' | * On shore at King George's Sound. † On shore at Port Louis, Mauritius. **General Table of the Inclinations observed on board Her Majesty's hired Bark "Pagoda."** | Date | Lat. | Long. | Inclination. | Mean. | Date | Lat. | Long. | Inclination. | Mean. | |------------|------|-------|--------------|-------|------------|------|-------|--------------|-------| | | | | Fox, F. I. | Fox, C. G. | | | | | | | 1844 | | | | | 1845 | | | | | | November | | | | | March | | | | | | 10 | -35°56' | 18°29' | -53°31' | * | 18 | -53°06' | 11°22' | -77°38' | -77°34' | | 21 | -35°56' | 18°29' | -53°31' | * | 19 | -3°10' | 11°26' | -76°41' | -77°09' | | December | | | | | 20 | -48°59' | 11°22' | -76°30' | -76°17' | | 7 | -34°12' | 18°26' | -53°50' | * | 22 | -47° | 11°55' | -75°31' | -75°32' | | 9 | -34°14' | 18°32' | -53°39' | * | 24 | -45°08' | 11°50' | -73°37' | -73°37' | | 13 | -35°29' | 15°09' | -51°27' | * | 25 | -43°21' | 11°50' | -72°45' | -72°28' | | 14 | -35°17' | 14°00' | -51°16' | * | 26 | -41°09' | 11°26' | -70°11' | -71°14' | | 15 | -35°18' | 13°26' | -51°35' | * | 27 | -38°46' | 11°15' | -68°49' | -68°04' | | 16 | -37°25' | 13°24' | -51°44' | * | 28 | -37°02' | 11°57' | -66°46' | -66°38' | | 17 | -38°40' | 14°27' | -52°39' | * | 29 | -36°12' | 11°49' | -65°28' | -65°44' | | 18 | -39°10' | 14°40' | -54°14' | * | 30 | -35°13' | 11°18' | -65°48' | -65°36' | | 19 | -40°31' | 14°23' | -55°10' | * | April | | | | | | 20 | -42°50' | 13°00' | -55°34' | * | 7 | -35°02' | 11°56' | -65°11' | -64°55' | | 21 | -44°50' | 13°19' | -56°14' | * | 11 | -35°02' | 11°56' | -65°11' | -64°59' | | 22 | -49°01' | 11°28' | -56°29' | * | 12 | -35°05' | 11°56' | -65°14' | -65°14' | | 23 | -48°35' | 10°51' | -56°44' | * | 20 | -35°06' | 11°55' | -65°39' | -65°39' | | 24 | -50°39' | 10°22' | -57°02' | * | 25 | -35°33' | 11°40' | -65°28' | -64°44' | | 25 | -51°49' | 9°33' | -57°13' | * | 24 | -34°16' | 11°01' | -64°44' | -64°44' | | 26 | -53°07' | 7°43' | -57°08' | * | 25 | -32°28' | 11°11' | -63°14' | -62°22' | | 27 | -53°57' | 6°05' | -57°01' | * | 27 | -31°18' | 10°52' | -59°30' | -59°35' | | 28 | -60°43' | 4°00' | -59°58' | * | 28 | -27°18' | 10°36' | -57°17' | -57°22' | | 29 | -61°10' | 9°05' | -61°16' | * | 29 | -25°53' | 10°03' | -55°09' | -55°07' | | February | | | | | May | | | | | | 1 | -62°06' | 12°52' | .............| -63°17' | | | | | | | 2 | -61°55' | 16°30' | -63°00' | * | 1 | -24°17' | 9°30' | -54°07' | -54°07' | | 3 | -61°50' | 19°14' | -63°55' | * | 2 | -24°02' | 9°27' | -52°44' | -52°44' | | 4 | -62°30' | 20°33' | -64°55' | * | 3 | -22°47' | 9°00' | -52°49' | -52°49' | | 5 | -63°19' | 21°48' | -65°35' | * | 4 | -21°47' | 8°41' | -52°17' | -51°45' | | 6 | -64°23' | 24°12' | -66°37' | * | 5 | -20°42' | 8°55' | -50°57' | -51°15' | | 7 | -65°37' | 28°39' | -66°59' | * | 6 | -20°38' | 8°14' | -51°14' | -51°18' | | 8 | -66°30' | 30°45' | -68°31' | * | 7 | -20°26' | 8°11' | -51°39' | -51°22' | | 9 | -66°33' | 36°48' | -68°16' | * | 8 | -20°36' | 7°16' | -51°46' | -51°48' | | 10 | -66°57' | 58°00' | -69°29' | * | 9 | -20°42' | 7°31' | -52°00' | -52°02' | | 11 | -67°57' | 40°00' | -69°49' | * | 10 | -20°39' | 7°43' | -51°58' | -51°59' | | 12 | -68°02' | 39°43' | -70°12' | * | 11 | -20°30' | 7°22' | -52°20' | -52°20' | | 13 | -68°58' | 40°12' | -69°39' | * | 12 | -20°27' | 7°41' | -52°19' | -52°35' | | 14 | -66°24' | 40°01' | -69°15' | * | 13 | -20°34' | 6°94' | -53°01' | -53°01' | | 15 | -64°52' | 38°37' | -68°40' | * | 14 | -21°07' | 6°08' | -53°10' | -53°06' | | 16 | -64°48' | 40°12' | -68°44' | * | 15 | -21°11' | 6°54' | -53°02' | -53°46' | | 17 | -64°22' | 40°49' | -68°40' | * | 16 | -21°12' | 6°29' | -53°59' | -53°49' | | 18 | -63°56' | 41°35' | -69°06' | * | 17 | -21°02' | 6°26' | -53°43' | -53°56' | | 19 | -63°20' | 45°44' | -70°03' | * | 18 | -20°40' | 6°58' | -53°53' | -53°53' | | 20 | -63°36' | 46°46' | -70°15' | * | 19 | -20°31' | 5°49' | -54°09' | -54°09' | | 21 | -62°36' | 51°40' | -69°13' | * | 20 | -20°09' | 5°71' | -54°14' | -54°38' | | 22 | -61°30' | 53°44' | -70°49' | * | 21 | -21°47' | 5°30' | -54°38' | -54°51' | | 23 | -61°19' | 57°34' | -72°01' | * | June | | | | | | 24 | -61°05' | 64°12' | -72°12' | * | 2 | -26°25' | 4°12' | -58°36' | -58°36' | | 25 | -61°43' | 71°06' | -73°58' | * | 3 | -26°26' | 4°20' | -58°46' | -58°46' | | 26 | -62°10' | 72°22' | -74°35' | * | 4 | -27°13' | 4°00' | -58°52' | -58°52' | | 27 | -62°42' | 74°12' | -74°50' | * | 5 | -28°12' | 4°50' | -58°10' | -58°51' | | March | | | | | 6 | -28°44' | 4°24' | -58°19' | -58°19' | | 1 | -60°03' | 95°50' | -77°35' | * | 7 | -28°35' | 4°20' | -58°54' | -58°54' | | 2 | -59°52' | 99°40' | -79°39' | * | 8 | -28°57' | 4°29' | -59°05' | -59°19' | | 3 | -57°40' | 99°23' | -78°36' | * | 9 | -30°27' | 3°31' | -56°37' | -56°37' | | 4 | -56°55' | 101°30' | -78°40' | * | 10 | -30°33' | 3°19' | -57°19' | -57°19' | | 5 | -55°46' | 103°12' | -78°56' | * | 11 | -31°06' | 3°30' | -57°28' | -57°26' | | 6 | -54°48' | 106°10' | -78°09' | * | 12 | -33°01' | 2°36' | -57°34' | -57°34' | | 7 | -54°14' | 108°10' | -78°49' | * | 13 | -34°31' | 2°04' | -57°06' | -57°06' | | | | | | | 14 | -35°46' | 2°35' | -56°08' | -56°08' | | | | | | | 15 | -35°38' | 2°10' | -55°31' | -55°25' | | | | | | | 16 | -35°07' | 2°46' | -55°08' | -55°08' | | | | | | | 17 | -34°12' | 1°26' | -53°37' | -53°37' | | | | | | | Magnetic Observatory, Cape of Good Hope, on the 2nd and 11th of July. | * Magnetic Observatory, Cape of Good Hope. † Dock Yard, Simon’s Bay. ‡ Probably a wrong degree; omitted in the mean. § Needle A. ¶ Needle B. || King George’s Sound. ** Port Louis, Mauritius. ### General Table of the Intensities of the Magnetic Force observed on board Her Majesty's hired Bark "Pagoda." | Date | Lat. | Long. | Intensity | Mean | Date | Lat. | Long. | Intensity | Mean | |------------|------|-------|-----------|------|------------|------|-------|-----------|------| | Dec. 1844 | | | | | March 1845 | | | | | | 1st and 5th| -33° 56' | 18° 29' | 0-999* | 0-999 | 19th | -51° 10' | 11° 26' | 1-787 | | | | -34° 12' | 18° 26' | 1-005† | 1-005 | 20th | -48° 59' | 112° 22' | 1-798 | | | 21st | | | | | 21st | -47° 21' | 115° 15' | 1-825 | | | January 1845 | 10th | 14° 45' | 0-981 | 0-983 | 24th | -45° 08' | 116° 50' | 1-820 | | | | 11th | 15° 09' | ... | 0-968 | 25th | -43° 21' | 116° 50' | 1-760 | | | | 12th | 14° 00' | ... | 0-923 | 26th | -41° 09' | 116° 26' | 1-746 | | | | 13th | 13° 26' | 0-950 | 0-942 | 27th | -38° 46' | 116° 15' | 1-738 | | | | 14th | 13° 24' | 0-965 | 0-965 | 28th | -37° 02' | 116° 57' | 1-695 | | | | 15th | 14° 27' | 0-908 | 0-978 | 29th | -36° 12' | 116° 49' | 1-673 | | | | 16th | 14° 40' | 0-989 | 0-977 | 30th | -35° 13' | 117° 18' | 1-702 | | | | 17th | 14° 23' | 0-994 | 0-989 | April 1845 | -35° 02' | 117° 56' | 1-688 | | | | 18th | 13° 00' | 0-997 | 0-997 | 7th | -35° 02' | 117° 56' | 1-688 | | | | 19th | 13° 19' | 1-007 | 1-007 | 11th | -35° 05' | 117° 56' | 1-688 | | | | 20th | 11° 28' | 1-051 | 1-051 | 12th | -35° 33' | 114° 40' | 1-688 | | | | 21st | 10° 51' | 1-060 | 1-060 | 23rd | -32° 28' | 111° 31' | 1-613 | | | | 22nd | 10° 22' | 1-094 | 1-094 | 24th | -31° 15' | 111° 41' | 1-614 | | | | 23rd | 10° 39' | 1-120 | 1-115 | 25th | -32° 28' | 111° 31' | 1-613 | | | | 24th | 9° 33' | 1-122 | 1-128 | 27th | -29° 18' | 106° 52' | 1-553 | | | | 25th | 7° 43' | 1-134 | 1-142 | 28th | -27° 41' | 106° 34' | 1-499 | | | | 26th | 6° 05' | 1-143 | 1-142 | 29th | -25° 53' | 105° 03' | 1-470 | | | | 27th | 5° 53' | 1-161 | 1-152 | May 1845 | -23° 59' | 99° 15' | 1-367 | | | | 28th | 4° 00' | 1-240 | 1-240 | 1st | -24° 01' | 97° 28' | 1-379 | | | | 29th | 3° 10' | 1-285 | 1-287 | 2nd | -23° 55' | 96° 01' | 1-365 | | | February 1845 | 1st | 12° 52' | ... | ... | 3rd | -24° 17' | 93° 50' | 1-352 | | | | 2nd | 16° 30' | 1-349 | 1-349 | 4th | -24° 02' | 92° 07' | 1-367 | | | | 3rd | 19° 14' | 1-334 | 1-334 | 5th | -22° 47' | 91° 00' | 1-324 | | | | 4th | 20° 33' | 1-353 | 1-350 | 6th | -21° 47' | 89° 41' | 1-326 | | | | 5th | 21° 48' | 1-362 | 1-362 | 7th | -20° 42' | 87° 55' | 1-294 | | | | 6th | 24° 12' | 1-401 | 1-400 | 8th | -20° 38' | 85° 14' | 1-265 | | | | 7th | 28° 39' | 1-432 | 1-432 | 9th | -20° 26' | 82° 11' | 1-257 | | | | 8th | 30° 45' | 1-448 | 1-448 | 10th | -20° 36' | 79° 16' | 1-247 | | | | 9th | 36° 48' | 1-482 | 1-476 | 11th | -20° 44' | 78° 31' | 1-238 | | | | 10th | 38° 50' | 1-491 | 1-483 | 12th | -20° 39' | 77° 43' | 1-237 | | | | 11th | 40° 00' | 1-519 | 1-496 | 13th | -20° 29' | 76° 22' | 1-222 | | | | 12th | 39° 53' | 1-494 | 1-496 | 14th | -20° 27' | 70° 41' | 1-199 | | | | 13th | 40° 12' | 1-499 | 1-490 | 15th | -20° 34' | 69° 24' | 1-210 | | | | 14th | 40° 01' | 1-494 | 1-494 | 16th | -21° 07' | 68° 08' | 1-191 | | | | 15th | 38° 37' | 1-470 | 1-450 | 17th | -21° 11' | 67° 54' | 1-203 | | | | 16th | 40° 12' | 1-463 | 1-482 | 18th | -21° 12' | 67° 29' | 1-201 | | | | 17th | 40° 49' | 1-460 | 1-460 | 19th | -21° 02' | 66° 26' | 1-181 | | | | 18th | 41° 35' | 1-416 | 1-453 | 20th | -20° 40' | 62° 58' | 1-173 | | | | 19th | 45° 44' | 1-437 | 1-462 | 21st | -20° 31' | 59° 42' | 1-171 | | | | 20th | 46° 46' | 1-457 | 1-470 | 22nd | -20° 09' | 57° 31' | 1-156 | | | | 21st | 51° 40' | 1-466 | 1-466 | 23rd | -21° 47' | 53° 30' | 1-179 | | | | 22nd | 53° 44' | 1-476 | 1-498 | 24th | -22° 25' | 49° 12' | 1-160 | | | | 23rd | 57° 34' | 1-535 | 1-506 | June 1845 | -22° 26' | 48° 20' | 1-164 | | | | 24th | 61° 12' | 1-553 | 1-560 | 25th | -22° 13' | 46° 00' | 1-129 | | | | 25th | 61° 05' | 1-604 | 1-605 | 26th | -22° 13' | 42° 50' | 1-125 | | | | 26th | 72° 25' | 1-657 | 1-642 | 27th | -28° 44' | 42° 01' | 1-117 | | | | 27th | 72° 12' | 1-656 | 1-655 | 28th | -28° 35' | 40° 24' | 1-128 | | | | 28th | 79° 38' | 1-706 | 1-692 | 29th | -28° 57' | 37° 49' | 1-094 | | | | 29th | 84° 54' | 1-689 | 1-730 | 30th | -30° 27' | 33° 41' | 1-105 | | | | 30th | 88° 23' | 1-729 | 1-747 | 31st | -30° 33' | 33° 19' | 1-085 | | | | 31st | 91° 14' | 1-759 | 1-749 | 32nd | -31° 06' | 31° 30' | 1-061 | | | | 1st | 92° 07' | 1-762 | 1-758 | 33rd | -33° 01' | 29° 36' | 1-046 | | | | 2nd | 92° 30' | 1-745 | 1-750 | 34th | -34° 31' | 27° 04' | 1-059 | | | | 3rd | 95° 30' | 1-798 | 1-770 | 35th | -35° 46' | 23° 35' | 1-033 | | | | 4th | 99° 40' | 1-772 | 1-836 | 36th | -35° 38' | 21° 40' | 1-025 | | | | 5th | 99° 23' | 1-968* | 1-813 | 37th | -35° 07' | 20° 46' | 1-013 | | | | 6th | 101° 30' | 1-786 | 1-802 | 38th | -34° 12' | 18° 26' | 1-012 | | | | 7th | 103° 12' | 1-816 | 1-815 | 39th | -34° 12' | 18° 26' | 1-001 | | | | 8th | 108° 10' | 1-816 | 1-817 | 40th | -34° 12' | 18° 26' | 1-000 | | * Observed on shore, Magnetic Observatory, Cape of Good Hope. † Observed on shore, Dock-yard, Simon’s Bay. ‡ Not included in the mean. § King George’s Sound; observed on shore. ¶ Port Louis, Mauritius; observed on shore. || Simon’s Bay, on board. Magnetic Observatory, Cape of Good Hope, 2nd and 11th of July. Observations of the Magnetic Inclination between the Cape of Good Hope and Van Diemen Island, by Lieut. Alexander Smith, R.N. | Date | Lat. | Long. | Corrected Inclination | |---------|--------|-------|-----------------------| | July 29 | -38° 00' | 4° 20' | -52° 00' | | 30 | -38° 28' | 7° 45' | -53° 03' | | 31 | -39° 06' | 12° 00' | -55° 42' | | August 1| -39° 42' | 15° 44' | -57° 06' | | 2 | -39° 33' | 23° 05' | -59° 32' | | 4 | -39° 33' | 26° 52' | -61° 47' | | 5 | -39° 50' | 28° 36' | -62° 08' | | 6 | -40° 01' | 32° 22' | -62° 56' | | 7 | -40° 32' | 36° 40' | -64° 09' | | 8 | -41° 06' | 41° 40' | -64° 42' | | 9 | -41° 00' | 46° 13' | -65° 19' | | 10 | -40° 43' | 49° 12' | -66° 08' | | 11 | -40° 56' | 53° 30' | -66° 25' | | 13 | -39° 34' | 60° 55' | -67° 27' | | 14 | ......... | ....... | -67° 18' | | 15 | -39° 00' | 65° 44' | -67° 19' | | 16 | -38° 31' | 68° 45' | -66° 45' | | 17 | -38° 22' | 70° 10' | -67° 06' | | 18 | -38° 08' | 73° 35' | -66° 45' | | 19 | -38° 10' | 75° 22' | -66° 42' | | Date | Lat. | Long. | Corrected Inclination | |---------|--------|-------|-----------------------| | Aug. 20 | -38° 25' | 76° 44' | -66° 54' | | 21 | -38° 48' | 77° 50' | -67° 14' | | 22 | -39° 04' | 79° 45' | -67° 17' | | 23 | -39° 58' | 84° 00' | -67° 43' | | 24 | -40° 06' | 87° 00' | -68° 13' | | 25 | -40° 06' | 90° 52' | -68° 41' | | 26 | -40° 02' | 95° 10' | -69° 08' | | 27 | -39° 52' | 99° 22' | -69° 00' | | 28 | -39° 54' | 102° 00' | -69° 00' | | 29 | -40° 08' | 105° 55' | -69° 22' | | 30 | -40° 31' | 109° 06' | -70° 02' | | 31 | -41° 16' | 113° 25' | -70° 30' | | Sept. 1 | -41° 54' | 117° 40' | -71° 20' | | 1 | -41° 58' | 119° 00' | -71° 33' | | 2 | -42° 17' | 122° 30' | -71° 45' | | 3 | -42° 35' | 125° 40' | -72° 08' | | 4 | -43° 00' | 129° 36' | -72° 08' | | 5 | -43° 16' | 133° 44' | -72° 13' | | 6 | -43° 28' | 137° 10' | -71° 55' | | 7 | -44° 06' | 141° 37' | -72° 14' | Observations of the Magnetic Force between the Cape of Good Hope and Van Diemen Island, by Lieut. Alexander Smith, R.N. | Date | Lat. | Long. | Method employed | Angle of deflection | Thermometer | Ship's head | Intensity, Hobarton = 1°800 | Remarks | |---------|--------|-------|-----------------|---------------------|-------------|-------------|-------------------------------|---------| | July 30 | -38° 28' | 27° 45' | wt. 2 grs. | 20° 13' | 52° | S.E. ½ E. | 0°953 | | | Aug. 5 | -39° 50' | 28° 36' | wt. 2 grs. | 17° 04' | 60 | S.E. by E. | 1°121 | | | | -39° 50' | 28° 36' | wt. 3 grs. | 26° 35' | 59 | S.E. by E. | 1°113 | | | 9 | -41° 00' | 46° 13' | wt. 2 grs. | 14° 50' | 60 | E. ½ S. | 1°288 | | | | -41° 00' | 46° 13' | wt. 3 grs. | 22° 46' | 61 | E. ½ S. | 1°288 | | | 15 | -39° 00' | 65° 44' | wt. 2 grs. | 13° 35' | 47 | S.E. by E.| 1°403 | Much motion. | | | -39° 00' | 65° 44' | wt. 3 grs. | 21° 26' | 44 | S.E. by E.| 1°364 | | | 18 | -38° 08' | 73° 35' | wt. 2 grs. | 12° 57' | 58 | E. | 1°471 | Smooth water. | | | -38° 08' | 73° 35' | wt. 3 grs. | 20° 18' | 59 | E. | 1°437 | | | 19 | -38° 10' | 75° 22' | wt. 2 grs. | 13° 28' | 66 | S.E. ½ E.| 1°415 | Smooth. | | | -38° 10' | 75° 22' | wt. 3 grs. | 20° 02' | 66 | S.E. ½ E.| 1°456 | | | 24 | -40° 06' | 87° 00' | wt. 2 grs. | 12° 14' | 64 | E.S.E. | 1°555 | | | | -40° 06' | 87° 00' | wt. 3 grs. | 17° 42' | 60 | E.S.E. | 1°597 | | | 28 | -39° 54' | 102° 00' | wt. 2 grs. | 11° 13' | 51 | E.S.E. | 1°640 | | | | -39° 54' | 102° 00' | wt. 3 grs. | 16° 31' | 51 | E.S.E. | 1°724 | | | 30 | -40° 31' | 109° 06' | wt. 2 grs. | 11° 04' | 58 | E.S.E. | 1°717 | | | | -40° 31' | 109° 06' | wt. 3 grs. | 16° 14' | 59 | E.S.E. | 1°751 | | | Sept. 3 | -42° 35' | 125° 40' | wt. 2 grs. | 10° 04' | 56 | E. by s. | 1°886 | | | | -42° 35' | 125° 40' | wt. 3 grs. | 15° 12' | 55 | E. by s. | 1°894 | | | 5 | -43° 14' | 133° 22' | wt. 2 grs. | 10° 21' | 49 | E. by s. | 1°834 | | | | -43° 14' | 133° 22' | wt. 3 grs. | 15° 11' | 48 | E. by s. | 1°869 | | | 6 | -43° 28' | 137° 10' | wt. 2 grs. | 10° 06' | 51 | E. ½ s. | 1°879 | | | | -43° 28' | 137° 10' | wt. 3 grs. | 15° 36' | 51 | E. ½ s. | 1°866 | | | Oct. 2 | -42° 52' | 147° 24' | wt. 2 grs. | 10° 33' | 54 | On shore. | 1°800 | | | | -42° 52' | 147° 24' | wt. 3 grs. | 16° 05' | 54 | | 1°800 | Hobarton: Magnetic Observatory. | Hobarton is taken as the base station; no correction has been applied for the effect of the ship's iron. In the results entered in the map of the Magnetic Force from Lieut. Smith's observations on the 24th, 28th, and 30th of August, the determinations with 2 grains only have been used; those with 3 grains are so discordant with other results as necessarily to indicate an error in them. Observations of the Magnetic Inclination between Van Diemen Island and the Cape of Good Hope, by Lieut. Joseph Dayman, R.N. | Date | Lat. | Long. | Corrected Inclination | |------|------|-------|-----------------------| | Dec. 6 | Hobarton Observatory | -70° 40' | | | 1844. | | | | | 16. | -44° 48' | 144° 51' | -71° 36' | | 17. | -44° 30' | 143° 56' | -70° 50' | | 18. | -44° 34' | 142° 51' | -71° 31' | | 19. | -44° 34' | 139° 37' | -73° 11' | | 20. | -43° 21' | 138° 37' | -70° 33' | | 21. | -42° 24' | 137° 18' | -70° 42' | | 23. | -41° 46' | 133° 26' | -70° 40' | | 24. | -42° 02' | 131° 31' | -72° 03' | | 26. | -41° 24' | 129° 30' | -70° 22' | | 27. | -42° 08' | 128° 45' | -71° 11' | | 28. | -40° 05' | 128° 23' | -70° 08' | | 30. | -39° 25' | 124° 04' | -69° 40' | | 31. | -38° 00' | 123° 38' | -68° 21' | | Date | Lat. | Long. | Corrected Inclination | |------|------|-------|-----------------------| | Jan. 25 | -24° 00' | 99° 33' | -54° 20' | | 1845. | | | | | 27. | -23° 11' | 95° 40' | -53° 44' | | 28. | -22° 54' | 93° 48' | -53° 26' | | 29. | -22° 19' | 91° 16' | -53° 11' | | 30. | -22° 17' | 89° 57' | -53° 11' | | 31. | -22° 11' | 86° 30' | -53° 20' | | Feb. 1 | -22° 08' | 84° 17' | -53° 52' | | 3. | -22° 34' | 80° 10' | -54° 23' | | 4. | -22° 35' | 78° 08' | -54° 26' | | 5. | -22° 38' | 76° 10' | -54° 45' | | 6. | -22° 28' | 74° 18' | -54° 41' | | 7. | -22° 33' | 72° 00' | -55° 04' | | 8. | -22° 41' | 69° 54' | -55° 54' | | 10. | -23° 52' | 64° 59' | -56° 52' | | 11. | -24° 23' | 62° 54' | -57° 57' | | 12. | -24° 50' | 61° 11' | -58° 15' | | 13. | -24° 43' | 59° 46' | -57° 59' | | 14. | -24° 36' | 58° 37' | -58° 17' | | 15. | -24° 45' | 57° 03' | -59° 13' | | 17. | -25° 13' | 51° 29' | -58° 34' | | 18. | -25° 42' | 49° 06' | -58° 43' | | 19. | -26° 54' | 45° 47' | -58° 41' | | 20. | -28° 15' | 42° 18' | -59° 37' | | 21. | -29° 21' | 39° 06' | -60° 01' | | 22. | -30° 10' | 36° 17' | -59° 08' | | 24. | -31° 19' | 33° 21' | -58° 32' | | 25. | -32° 17' | 29° 34' | -58° 16' | | 26. | -34° 02' | 26° 53' | -57° 23' | | 27. | -34° 35' | 25° 31' | -56° 45' | | 28. | -34° 36' | 25° 23' | -56° 35' | | March 1 | -34° 40' | 24° 16' | -56° 32' | | 3. | -34° 04' | 22° 45' | -56° 43' | | 4. | -34° 29' | 21° 44' | -55° 36' | | 5. | -34° 48' | 19° 33' | -54° 50' | Observations of the Magnetic Force between Van Diemen Island and the Cape of Good Hope, by Lieut. Joseph Dayman, R.N. | Date | Lat. | Long. | Weights. | Angle of deflection | Thermometer | Ship's head. | Intensity. | Correction for ship's attraction. | Corrected Intensity, Hobarton = 1·800 | Remarks | |--------|------|-------|----------|---------------------|-------------|--------------|------------|-----------------------------------|-------------------------------------|---------| | 1844. Dec. 6. | -42° 52' | 147° 24' | 2 grs. | 10° 43' 71" | On shore | 1·800 | 1·800 | ……… | 1·800 | Magnetic Observatory, Hobarton. | | | -42° 52' | 147° 24' | 3 | 16° 11' 71" | w. by s. | 1·863 | -0·041 | 1·827 | | | -44° 48' | 144° 51' | 2 | 10° 21' 55" | w. by s. | 1·873 | -0·041 | 1·815 | | | -44° 48' | 144° 51' | 3 | 15° 32' 55" | w. by s. | 1·834 | -0·041 | 1·815 | | | -44° 30' | 143° 56' | 2 | 10° 31' 67" | w. by s. | 1·879 | -0·041 | 1·815 | | | -44° 30' | 143° 56' | 3 | 15° 29' 67" | w. by s. | 1·866 | -0·041 | 1·818 | | | -44° 34' | 142° 51' | 2 | 10° 20' 69" | w. by s. | 1·851 | -0·041 | 1·818 | | | -44° 34' | 142° 51' | 3 | 15° 44' 70" | s.w. by s. | 1·901 | -0·053 | 1·848 | | | -44° 34' | 139° 37' | 3 | 15° 18' 63" | w. | 1·840 | -0·037 | 1·828 | | | -42° 24' | 137° 18' | 2 | 10° 29' 69" | w. | 1·889 | -0·020 | 1·846 | | | -42° 24' | 137° 18' | 3 | 15° 24' 70" | n. | 1·831 | -0·020 | 1·846 | | | -41° 46' | 133° 26' | 2 | 10° 32' 58" | n. | 1·901 | -0·020 | 1·846 | | | -41° 46' | 133° 26' | 3 | 15° 18' 57" | n. | 1·912 | -0·020 | 1·856 | | | -40° 05' | 128° 23' | 2 | 10° 05' 63" | N.W. by n. | 1·840 | -0·020 | 1·856 | | | -40° 05' | 128° 23' | 3 | 15° 49' 63" | N.W. by n. | 1·814 | -0·020 | 1·793 | | | -39° 25' | 124° 04' | 2 | 10° 38' 65" | N. by w. | 1·813 | -0·020 | 1·793 | | | -39° 25' | 124° 04' | 3 | 16° 04' 65" | N. by w. | 1·852 | -0·020 | 1·799 | | | -38° 00' | 123° 38' | 2 | 10° 25' 62" | N.N.W. | 1·786 | -0·020 | 1·799 | | | -38° 00' | 123° 38' | 3 | 16° 19' 62" | N.N.W. | 1·786 | -0·020 | 1·799 | | 1845. Jan. 1. | -38° 21' | 122° 46' | 2 | 10° 49' 71" | N.W. by w. | 1·783 | -0·025 | 1·777 | | | -38° 21' | 122° 46' | 3 | 15° 59' 72" | N.W. by w. | 1·822 | -0·025 | 1·777 | | | -37° 14' | 124° 58' | 2 | 10° 55' 69" | N.W. | 1·767 | -0·020 | 1·771 | | | -37° 14' | 124° 58' | 3 | 16° 03' 69" | N.W. | 1·815 | -0·020 | 1·771 | | | -36° 28' | 118° 57' | 2 | 11° 11' 67" | N.N.W. | 1·725 | -0·020 | 1·716 | | | -36° 28' | 118° 57' | 3 | 16° 41' 67" | N.N.W. | 1·747 | -0·020 | 1·716 | | | -35° 22' | 117° 46' | 2 | 11° 04' 65" | N.N.W. | 1·743 | -0·020 | 1·722 | | | -35° 22' | 117° 46' | 3 | 16° 44' 64" | N.N.W. | 1·742 | -0·020 | 1·722 | | | -34° 06' | 116° 42' | 2 | 10° 55' 68" | S.S.W. | 1·767 | -0·055 | 1·715 | | | -34° 06' | 116° 42' | 3 | 16° 26' 68" | S.S.W. | 1·773 | -0·055 | 1·715 | | | -34° 58' | 112° 59' | 2 | 11° 24' 66" | N.W. | 1·693 | -0·012 | 1·686 | | | -34° 58' | 112° 59' | 3 | 17° 07' 66" | N.W. | 1·704 | -0·012 | 1·686 | | | -33° 47' | 111° 04' | 2 | 11° 54' 67" | N.W. by w. | 1·623 | -0·017 | 1·609 | | | -33° 47' | 111° 04' | 3 | 17° 53' 67" | N.W. by w. | 1·629 | -0·017 | 1·609 | | | -33° 37' | 108° 24' | 2 | 11° 57' 69" | N.W. by w. | 1·616 | -0·017 | 1·603 | | | -33° 37' | 108° 24' | 3 | 17° 59' 69" | N.W. by w. | 1·624 | -0·017 | 1·603 | | | -29° 40' | 105° 28' | 2 | 12° 30' 72" | N.W. | 1·546 | -0·007 | 1·537 | | | -29° 40' | 105° 28' | 3 | 18° 58' 72" | N.W. | 1·543 | -0·007 | 1·537 | | | -28° 04' | 103° 06' | 2 | 13° 02' 73" | N. | 1·484 | -0·004 | 1·493 | | | -28° 04' | 103° 06' | 3 | 19° 24' 73" | N. | 1·510 | -0·004 | 1·493 | | | -26° 44' | 104° 26' | 2 | 13° 03' 76" | N.W. | 1·483 | -0·007 | 1·466 | | | -26° 44' | 104° 26' | 3 | 20° 05' 76" | N.W. | 1·462 | -0·007 | 1·466 | | | -25° 52' | 102° 58' | 2 | 13° 39' 75" | N.W. | 1·418 | -0·007 | 1·421 | | | -25° 52' | 102° 58' | 3 | 20° 24' 75" | N.W. | 1·439 | -0·007 | 1·421 | | | -24° 50' | 101° 31' | 2 | 13° 31' 76" | N.W. | 1·432 | -0·006 | 1·415 | | | -24° 50' | 101° 31' | 3 | 20° 51' 76" | N.W. | 1·410 | -0·006 | 1·415 | | | -24° 00' | 99° 33' | 2 | 13° 30' 75" | W.N.W. | 1·435 | -0·010 | 1·407 | | | -24° 00' | 99° 33' | 3 | 21° 02' 75" | W.N.W. | 1·400 | -0·010 | 1·407 | | | -23° 11' | 95° 40' | 2 | 14° 22' 78" | w. by n. | 1·350 | -0·012 | 1·334 | | | -23° 11' | 95° 40' | 3 | 21° 58' 78" | w. by n. | 1·342 | -0·012 | 1·334 | | | -22° 54' | 93° 48' | 2 | 14° 16' 78" | w. by n. | 1·360 | -0·012 | 1·337 | | | -22° 54' | 93° 48' | 3 | 22° 03' 79" | w. by n. | 1·338 | -0·012 | 1·337 | | | -22° 19' | 91° 16' | 2 | 15° 02' 77" | w. | 1·291 | -0·017 | 1·277 | | | -22° 19' | 91° 16' | 3 | 22° 46' 77" | w. | 1·297 | -0·017 | 1·277 | | | -22° 17' | 89° 57' | 2 | 14° 58' 80" | w. | 1·296 | -0·017 | 1·288 | | | -22° 17' | 89° 57' | 3 | 22° 28' 81" | w. | 1·314 | -0·017 | 1·288 | | | -22° 11' | 86° 30' | 2 | 15° 11' 80" | w. | 1·278 | -0·017 | 1·274 | | | -22° 11' | 86° 30' | 3 | 22° 38' 80" | w. | 1·304 | -0·017 | 1·274 | | Date | Lat. | Long. | Weights. | Angle of deflection. | Thermometer. | Ship's head. | Intensity. | Correction for ship's attraction. | Corrected Intensity. Hobarton = 1·800. | Remarks | |------|------|-------|----------|---------------------|--------------|--------------|------------|----------------------------------|---------------------------------|---------| | Feb. 1. | -22° 08' | 84° 17' | 2 | 15° 13' | 81 | W. ½ N. | 1·275 | -0·017 | 1·251 | | | -22° 08' | 84° 17' | 3 | 23° 25' | 81 | W. ½ N. | 1·262 | -0·019 | 1·261 | | | -22° 34' | 80° 10' | 2 | 15° 16' | 83 | W. ¼ N. | 1·272 | -0·015 | 1·237 | | | -22° 34' | 80° 10' | 3 | 22° 55' | 83 | W. ¼ N. | 1·288 | -0·015 | 1·237 | | | -22° 35' | 78° 08' | 2 | 15° 42' | 83 | W. ¼ N. | 1·237 | -0·015 | 1·237 | | | -22° 35' | 78° 08' | 3 | 23° 20' | 83 | W. ¼ N. | 1·267 | -0·015 | 1·237 | | | -22° 38' | 76° 10' | 2 | 15° 31' | 82 | W. ¾ N. | 1·252 | -0·015 | 1·236 | | | -22° 38' | 76° 10' | 3 | 23° 41' | 82 | W. ¾ N. | 1·250 | -0·015 | 1·236 | | | -22° 28' | 74° 18' | 2 | 15° 50' | 82 | W. ¾ N. | 1·227 | -0·015 | 1·216 | | | -22° 28' | 74° 18' | 3 | 23° 58' | 82 | W. ¾ N. | 1·236 | -0·015 | 1·216 | | | -22° 33' | 72° 20' | 2 | 15° 49' | 81 | W. ½ N. | 1·229 | -0·016 | 1·211 | | | -22° 33' | 72° 20' | 3 | 24° 11' | 81 | W. ½ N. | 1·225 | -0·016 | 1·211 | | | -22° 41' | 69° 54' | 2 | 15° 38' | 81 | W. | 1·240 | -0·018 | 1·215 | | | -22° 41' | 69° 54' | 3 | 24° 13' | 81 | W. | 1·223 | -0·018 | 1·215 | | | -23° 52' | 64° 59' | 2 | 15° 58' | 84 | W. ½ S. | 1·217 | -0·022 | 1·196 | | | -23° 52' | 64° 59' | 3 | 24° 20' | 84 | W. ½ S. | 1·218 | -0·022 | 1·196 | | | -24° 23' | 62° 54' | 2 | 16° 13' | 83 | W. ½ S. | 1·199 | -0·022 | 1·177 | | | -24° 23' | 62° 54' | 3 | 24° 44' | 83 | W. ½ S. | 1·199 | -0·022 | 1·177 | | | -24° 50' | 61° 11' | 2 | 16° 01' | 84 | W. ½ N. | 1·214 | -0·018 | 1·197 | | | -24° 50' | 61° 11' | 3 | 24° 22' | 84 | W. ½ N. | 1·216 | -0·018 | 1·197 | | | -24° 43' | 59° 46' | 2 | 16° 17' | 85 | W. by N. ½ N. | 1·194 | -0·011 | 1·184 | | | -24° 43' | 59° 46' | 3 | 24° 47' | 85 | W. by N. ½ N. | 1·197 | -0·011 | 1·184 | | | -24° 36' | 58° 37' | 2 | 16° 23' | 85 | W. by N. ½ N. | 1·187 | -0·011 | 1·178 | | | -24° 36' | 58° 37' | 3 | 24° 55' | 84 | W. by N. ½ N. | 1·191 | -0·011 | 1·178 | | | -25° 13' | 51° 29' | 2 | 16° 46' | 84 | W. ¾ N. | 1·160 | -0·017 | 1·139 | | | -25° 13' | 51° 29' | 3 | 25° 49' | 84 | W. ¾ N. | 1·152 | -0·017 | 1·139 | | | -25° 42' | 49° 06' | 2 | 17° 09' | 82 | W. | 1·135 | -0·020 | 1·114 | | | -25° 42' | 49° 06' | 3 | 26° 16' | 81 | W. | 1·133 | -0·020 | 1·114 | | | -28° 15' | 42° 18' | 2 | 17° 43' | 81 | W. ½ S. | 1·100 | -0·022 | 1·086 | | | -28° 15' | 42° 18' | 3 | 26° 44' | 81 | W. ½ S. | 1·116 | -0·022 | 1·086 | | | -29° 21' | 39° 06' | 2 | 17° 46' | 81 | W. | 1·097 | -0·020 | 1·081 | | | -29° 21' | 39° 06' | 3 | 26° 59' | 81 | W. | 1·106 | -0·020 | 1·081 | | | -30° 10' | 36° 17' | 2 | 17° 55' | 82 | W. ½ N. | 1·088 | -0·018 | 1·076 | | | -30° 10' | 36° 17' | 3 | 27° 07' | 82 | W. ½ N. | 1·101 | -0·018 | 1·076 | | | -31° 19' | 32° 21' | 2 | 18° 29' | 83 | W. ½ N. | 1·056 | -0·016 | 1·046 | | | -31° 19' | 32° 21' | 3 | 28° 01' | 83 | W. ½ N. | 1·068 | -0·016 | 1·046 | | | -32° 17' | 29° 34' | 2 | 18° 59' | 82 | W. ¾ N. | 1·029 | -0·014 | 1·026 | | | -32° 17' | 29° 34' | 3 | 28° 28' | 82 | W. ¾ N. | 1·052 | -0·014 | 1·026 | | | -34° 02' | 26° 53' | 2 | 18° 57' | 74 | W. | 1·030 | -0·018 | 1·012 | | | -34° 02' | 26° 53' | 3 | 28° 37' | 74 | S.W. | 1·047 | -0·035 | 1·012 | | | -34° 36' | 25° 23' | 2 | 18° 38' | 71 | S.W. ½ W. | 1·047 | -0·030 | 1·021 | | | -34° 36' | 25° 23' | 3 | 28° 22' | 71 | S.W. ½ W. | 1·056 | -0·030 | 1·021 | | | -34° 40' | 24° 16' | 2 | 19° 27' | 79 | W.N.W. | 1·005 | -0·007 | 1·004 | | | -34° 40' | 24° 16' | 3 | 29° 35' | 79 | W.N.W. | 1·016 | -0·007 | 1·004 | | | -34° 48' | 19° 33' | 2 | 19° 51' | 71 | N.W. ½ N. | 0·986 | -0·000 | 0·984 | | | -34° 48' | 19° 33' | 3 | 30° 46' | 70 | N.W. ½ N. | 0·981 | -0·000 | 0·984 | Observations of the Magnetic Declination, made on board Her Majesty's Ship Erebus, by Captain Sir James Clark Ross, between the Cape of Good Hope and Van Diemen Island. | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Remarks | |------------|------|-------|----------|----------------------|-------------|-------------|----------------------------------|----------------------|---------| | 1840. | | | | | | | | | | | April 8. | -35° | 52' | T. | +28° 28' | W. | | +2° 05' +30° 33' | | | | | | | T. | +31° 52' | E.S.E. | | -2° 13' +29° 39' | | | | | | | O. | +31° 50' | E.S.E. | | -2° 13' +29° 37' | | | | | | | T. | +32° 13' | S.E. by E. | | -2° 07' +30° 06' | | | | | | | S. | +30° 44' | S. | | 0° 00' +30° 44' | | | | | | | R. | +31° 50' | S.E. ½ S. | | -53° 40' | | | | | | | T. | +31° 39' | S.E. ½ S. | | -1° 45' +30° 05' | | | | | | | T. | +32° 02' | S.S.E. ½ E. | | -1° 48' +29° 51' | | | | | | | S. | +30° 03' | S.W. | | +2° 00' +32° 03' | | | | | | | O. | +30° 41' | s. by w. | | +0° 37' +31° 18' | | | | | | | T. | +29° 56' | s. by w. | | +0° 37' +30° 33' | | | | | | | T. | +30° 26' | s. | | 0° 00' +30° 26' | | | | | | | S. | +30° 17' | s. | | 0° 00' +30° 17' | | | | | | | T. | +30° 20' | s. | | 0° 00' +30° 20' | | | | | | | R. | +30° 14' | s. | | 0° 00' +30° 14' | | | | | | | T. | +30° 19' | S. ½ E. | | -55° 30' | | | | | | | O. | +31° 00' | S. ½ E. | | -0° 19' +30° 00' | | | | | | | S. | +30° 41' | S. ½ E. | | -0° 19' +30° 41' | | | | | | | T. | +31° 11' | S. ½ E. | | -0° 19' +30° 22' | | | | | | | R. | +31° 29' | s. | | 0° 00' +31° 29' | | | | | | | T. | +31° 02' | S. ½ E. | | -0° 19' +30° 43' | | | | | | | R. | +30° 01' | s. | | 0° 00' +30° 01' | | | | | | | T. | +31° 53' | S. ½ W. | | +0° 19' +32° 12' | | | | | | | T. | +32° 09' | S. ½ E. | | -0° 19' +31° 50' | | | | | | | T. | +32° 10' | s. by E. | | -0° 38' +31° 32' | | | | | | | T. | +31° 50' | s. by E. | | -0° 38' +31° 12' | | | | | | | O. | +31° 09' | s. by E. | | -0° 38' +30° 31' | | | | | | | S. | +31° 16' | s. by E. | | -0° 38' +30° 38' | | | | | | | T. | +31° 14' | s. by E. | | -0° 38' +30° 36' | | | | | | | R. | +28° 57' | s. by E. | | -0° 38' +28° 19' | | | | | | | S. | +32° 43' | S.E. ½ E. | | -2° 16' +30° 27' | | | | | | | T. | +31° 10' | s.w. by w. | | +2° 23' +33° 33' | | | | | | | T. | +30° 04' | s.w. | | +2° 09' +32° 13' | | | | | | | T. | +30° 20' | s.w. | | +2° 09' +32° 29' | | | | | | | T. | +29° 51' | S.S.W. | | -59° 30' | | | | | | | T. | +32° 30' | S.E. by S. | | -59° 40' | | | | | | | S. | +31° 20' | S.E. by S. | | -1° 46' +30° 23' | | | | | | | T. | +32° 09' | S.S.E. ½ E. | | -2° 17' +30° 18' | | | | | | | S. | +31° 00' | S.E. by S. | | -2° 03' +28° 57' | | | | | | | T. | +32° 45' | S.S.E. ½ E. | | -1° 46' +30° 59' | | | | | | | R. | +32° 41' | S.S.E. | | -1° 24' +31° 17' | | | | | | | T. | +32° 00' | S.S.E. | | -1° 24' +30° 36' | | | | | | | S. | +31° 48' | S.S.E. | | -1° 26' +30° 22' | | | | | | | T. | +34° 43' | S.S.E. | | -1° 26' +33° 17' | | | | | | | T. | +34° 27' | S.S.E. | | -1° 26' +33° 01' | | | | | | | S. | +34° 43' | S.S.E. | | -1° 26' +33° 17' | | | | | | | O. | +35° 58' | S.S.E. | | -1° 26' +34° 32' | | | | | | | R. | +33° 58' | S.S.E. | | -1° 26' +32° 32' | | | | | | | T. | +33° 39' | s. by E. | | -1° 26' +32° 43' | | | | | | | R. | +35° 44' | S.E. | | -3° 03' +32° 41' | | | | | | | T. | +31° 44' | N.W. | | +2° 12' +33° 56' | | | | | | | T. | +31° 53' | N.N.W. | | +1° 07' +33° 00' | | | MDCCXLVI. ## Observations of Declination. (Continued.) | Date | Lat. | Long. | Observer | Declination observed | Ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Remarks | |------------|--------|-------|----------|----------------------|-------------|-------------|----------------------------------|----------------------|---------| | 1840. | | | | | | | | | | | April 30. | -46° 32' 52" 01' | T. | +3° 40' N. by E. ½ E. | -67° 30' +0° 53' | +3° 33' +33° 16' | | May 1. | -46° 32' 52" 01' | R. | +37° 06' S.E. | -67° 30' -3° 07' | +33° 59' | | 2. | -47° 03' 56" 17' | S. | +36° 34' S.E. | -67° 50' -3° 07' | +33° 27' | | | | T. | +33° 48' S.E. | -67° 50' -3° 07' | +30° 41' | | | | R. | +33° 34' S.E. | -67° 50' -3° 07' | +30° 27' | | | | T. | +32° 21' S.E. | -68° 30' -3° 15' | +29° 06' | | | | S. | +32° 10' S.E. | -68° 30' -3° 15' | +28° 55' | | July 27. | -47° 18' 93" 36' | R. | +30° 00' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | | | R. | +31° 50' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | | | R. | +30° 32' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | | | R. | +29° 39' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | | | R. | +29° 34' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | | | T. | +24° 09' S.E. by E. ½ E. | -72° 30' -4° 41' | +25° 38' | | Aug. 31. | -47° 34' 105" 47' | T. | +16° 39' E.by S. ½ S. | -74° 10' -5° 10' | +18° 59' | | 2. | -47° 45' 113" 49' | R. | +15° 58' E.by S. ½ S. | -75° 10' -5° 49' | +11° 29' | | | | T. | +17° 58' E. ½ S. | -75° 30' -5° 51' | +9° 34' | | | | R. | +15° 26' E. ½ S. | -75° 30' -5° 51' | +9° 34' | | | | R. | +15° 11' E. ½ S. | -75° 30' -5° 51' | +9° 34' | | | | R. | +15° 39' E. ½ S. | -75° 30' -5° 51' | +9° 34' | | | | T. | +1° 58' E. ½ N. | -75° 00' -5° 43' | -1° 00' | | | | T. | +3° 44' E.by N. | -75° 00' -5° 43' | -1° 00' | | | | T. | +3° 08' E. ½ N. | -75° 00' -5° 43' | -1° 00' | | | | T. | +5° 43' E. ½ N. | -75° 00' -5° 43' | -1° 00' | | | | R. | +5° 58' E. | -75° 00' -5° 43' | -1° 00' | | | | R. | +6° 30' E. | -75° 00' -5° 43' | -1° 00' | | | | R. | +4° 29' E. | -75° 00' -5° 43' | -1° 00' | | | | R. | +5° 16' E. | -75° 00' -5° 43' | -1° 00' | | | | R. | +2° 09' E. | -75° 00' -5° 43' | -1° 00' | | | | R. | +6° 17' E. ½ N. | -75° 00' -5° 35' | -0° 34' | | | | R. | +6° 53' E. ½ N. | -75° 00' -5° 35' | -0° 34' | | | | R. | +7° 25' E. ½ N. | -75° 00' -5° 35' | -0° 34' | | | | R. | -3° 06' N. | -75° 00' -5° 35' | -0° 34' | | 10. | -44° 23' 141" 11' | T. | -4° 19' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | R. | -3° 12' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | T. | -3° 12' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | R. | -4° 01' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | T. | -3° 39' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | R. | -4° 24' E.N.E. | -73° 00' -4° 20' | -7° 52' | | | | T. | -2° 01' E.N.E. | -73° 00' -4° 20' | -7° 52' | The observers are distinguished by their initials as follows: - R., Sir James Ross; S., Lieut. Sibbald; T., Mr. Tucker, Master; O., Mr. Oakley, Mate. Observations of the Magnetic Inclination taken on board Her Majesty's Ship Erebus, by Captain Sir James Clark Ross, with Needle F. I., between the Cape of Good Hope and Kerguelen Island. | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |------------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | 1840. | | | | | | | | | | April 7. | −35° 14' 18" 27' | Direct. | −54° 23' s. by E. | −04 | −2° 0 | −54° 32 | | | | | | S. | −54° 30 | E.S.E. | | | | | | | | Direct. | −54° 34 | | +23 | −2° 0 | −54° 18 | | | | | | S. | −54° 39 | | | | | | | | | Direct. | −54° 38 w. by s. | | +34 | −2° 0 | −55° 24 | | | | | | S. | −54° 47 | | | | | | | | | Direct. | −55° 42 | | | | | | | | | S. | −56° 10 | | | | | | | | | Direct. | −55° 49 s.E. by s. | | +02 | −2° 0 | −55° 50 | | | | | | S. | −55° 51 | | | | | | | | | Direct. | −55° 30 s. | | −10 | −2° 0 | −55° 38 | | | | | | S. | −55° 36 | | | | | | | | | S.N. | −55° 26 | | | | | | | | | N. | −55° 14 | | | | | | | | | Direct. | −55° 27 s. | | | | | | | | | S. | −56° 01 | | −10 | −2° 0 | −56° 03 | | | | | | Direct. | −55° 42 | | | | | | | | | S. | −56° 11 | | | | | | | | | Direct. | −55° 56 | | | | | | | | | Direct. | −55° 41 w.s.w. | | +22 | −2° 0 | −55° 35 | Much motion. | | | | | S. | −56° 09 | | | | | | | | | Direct. | −56° 27 s.s.E. | | −08 | −2° 0 | −56° 33 | | | | | | S. | −56° 19 | | | | | | | | | Direct. | −57° 13 s.E. by s. | | −06 | −2° 0 | −57° 28 | | | | | | S. | −57° 28 | | | | | | | | | Direct. | −58° 00 s.E. by s. | | −08 | −2° 0 | −58° 21 | | | | | | S. | −58° 11 | | | | | | | | | S.N. | −58° 11 | | | | | | | | | N. | −58° 11 | | | | | | | | | Direct. | −58° 22 s.s.E. | | −15 | −2° 0 | −58° 43 | | | | | | S. | −58° 31 | | | | | | | | | Direct. | −59° 01 s.s.E. | | −19 | −2° 0 | −59° 31 | | | | | | S. | −59° 20 | | | | | | | | | S.N. | −59° 20 | | | | | | | | | N. | −59° 21 | | −20 | −2° 0 | −59° 37 | | | | | | Direct. | −59° 05 | | | | | | | | | Direct. | −60° 30 s. by E. | | −29 | −2° 0 | −60° 52 | | | | | | S. | −60° 13 | | | | | | | | | Direct. | −61° 41 s.s.E. | | −30 | −2° 0 | −62° 23 | | | | | | S. | −62° 01 | | | | | | | | | Direct. | −63° 28 s.E. by s. | | −28 | −2° 0 | −64° 00 | | | | | | S. | −63° 32 | | | | | | | | | Direct. | −63° 52 s.E. by s. | | −29 | −2° 0 | −64° 30 | | | | | | S. | −64° 06 | | | | | | | | | Direct. | −64° 59 s.E. by s. | | −32 | −2° 0 | −65° 47 | Much motion. | | | | | S. | −65° 32 | | | | | | | | | Direct. | −65° 09 | | | | | | | | | Direct. | −66° 18 s.E. ½ E. | | −15 | −2° 0 | −66° 36 | Very steady. | | | | | S. | −66° 20 | | | | | | | | | Direct. | −67° 00 s.E. by s. | | −36 | −2° 0 | −67° 41 | | | | | | S. | −67° 06 | | | | | | | | | Direct. | −67° 31 w.s.w. | | +03 | −2° 0 | −67° 30 | | 3 k 2 ### Observations of the Magnetic Inclination. (Continued.) | Date | Lat. | Long. | Method employed | Observed Inclination | Ship's head | Corrections | Corrected Inclination | Remarks | |---------|--------|-------|-----------------|----------------------|-------------|-------------|----------------------|---------| | Apr. 29 | -46° 25' 52" 24' | Direct. | -67° 11' s.w. by w. | -11 | -2° | -67° 29' | | | | | S. | -67° 21' | -45 | -2° | -67° 10' | | | | | S. | -66° 20' | -47 | -2° | -67° 30' | | | May 1 | -46° 25' 52" 01' | Direct. | -66° 26' s.by E. ½ E. | -47 | -2° | -67° 30' | | | | | S. | -66° 39' | -47 | -2° | -67° 30' | | | | | S.N. | -66° 40' | -47 | -2° | -67° 30' | | | | | N. | -67° 00' | -47 | -2° | -67° 30' | | | | -46° 57' 55" 34' | Direct. | -67° 37' s.e. | -26 | -2° | -68° 12' | | | | | S. | -67° 51' | -26 | -2° | -68° 12' | | | | -47° 19' 59" 10' | Direct. | -68° 19' s.e. | -27 | -2° | -68° 42' | | | | | S. | -68° 27' | -27 | -2° | -68° 42' | | | | | S.N. | -67° 59' | -27 | -2° | -68° 42' | | | | | N. | -68° 69' | -27 | -2° | -68° 42' | | | | -47° 40' 62" 25' | Direct. | -69° 13' s.e. | -28 | -2° | -69° 37' | | | | | S. | -69° 02' | -28 | -2° | -69° 37' | | | | -48° 36' 69" 20' | Direct. | -71° 23' n.n.w. | +69 | -2° | -69° 37' | | | | | S. | -71° 36' | -28 | -2° | -69° 37' | | | | -48° 36' 69" 07' | Direct. | -69° 12' s.w.by s. | -42 | -2° | -70° 12' | | | | | S. | -69° 25' | -42 | -2° | -70° 12' | | | | -48° 24' 69" 44' | Direct. | -69° 19' s.w.by w.½ w. | -08 | -2° | -69° 33' | | | | | S. | -69° 28' | -08 | -2° | -69° 33' | | | | -48° 40' 68" 58' | Direct. | -71° 47' n. | -72 | -2° | -71° 35' | | | | | S. | -72° 03' | -72 | -2° | -71° 35' | | | | | Direct. | -69° 46' s.w.by w.½ w. | -08 | -2° | -71° 35' | | | | | S. | -69° 59' | -08 | -2° | -71° 35' | | Abstract of Observations of the Magnetic Force between the Cape of Good Hope and Kerguelen Island, made in Her Majesty's Ships Erebus and Terror in 1840*. | Position | Intensity | Position | Intensity | |----------|-----------|----------|-----------| | Lat. | Long. | Lat. | Long. | | Cape = 0°981 | Cape = 1°000 | Cape = 0°981 | Cape = 1°000 | | -34° 11' | 18° 26' | -43° 07' | 28° 43' | | -37° 44' | 16° 36' | -47° 00' | 38° 48' | | -35° 14' | 18° 27' | -45° 44' | 34° 16' | | -36° 04' | 19° 19' | -46° 45' | 40° 05' | | -37° 16' | 17° 24' | -47° 00' | 37° 14' | | -36° 16' | 20° 04' | -47° 00' | 43° 48' | | -36° 52' | 18° 25' | -46° 46' | 42° 41' | | -36° 11' | 20° 42' | -47° 50' | 45° 20' | | -35° 48' | 18° 47' | -47° 01' | 46° 10' | | -38° 47' | 17° 00' | -46° 41' | 50° 52' | | -36° 35' | 21° 20' | -46° 28' | 52° 43' | | -38° 58' | 17° 26' | -46° 29' | 52° 26' | | -40° 05' | 20° 38' | -46° 25' | 52° 01' | | -40° 45' | 19° 20' | -46° 57' | 55° 39' | | -38° 13' | 21° 30' | -46° 18' | 52° 04' | | -42° 40' | 22° 02' | -47° 19' | 59° 10' | | -41° 24' | 25° 00' | -47° 41' | 62° 59' | | -42° 56' | 23° 12' | -48° 41' | 68° 54' | | -40° 29' | 22° 22' | -48° 41' | 68° 54' | | -41° 58' | 26° 38' | -48° 39' | 68° 57' | | -44° 28' | 24° 55' | -48° 36' | 69° 07' | | -46° 41' | 29° 00' | -48° 36' | 69° 21' | | -46° 00' | 26° 12' | -48° 30' | 69° 52' | | -44° 19' | 31° 06' | -48° 30' | 69° 52' | * Philosophical Transactions, 1842, p. 41. † On shore in Simon's Bay. ‡ On shore at Kerguelen Island.