Contributions to Terrestrial Magnetism.--No. V

X. Contributions to Terrestrial Magnetism.—No. V. By Lieut.-Colonel Edward Sabine, R.A., F.R.S. Received June 14,—Read June 15, 1843. § 8. Observations within the Antarctic Circle, made on Board Her Majesty's Ships Erebus and Terror, in the Summer of 1840, 1841, in the Expedition under the command of Captain James Clark Ross, R.N. § 9. Observations between Kerguelen Island and Van Diemen Island, made on Board Her Majesty's Ship Erebus, July and August 1840. § 8. Observations within the Antarctic Circle in the Summer of 1840, 1841. In the present number of these Contributions, I have the pleasure of laying before the Royal Society the magnetic observations made by Captain James Clark Ross, and the Expedition under his command, in the first of the three voyages in which these researches have been prosecuted within the Antarctic Circle; and I gladly avail myself of the opportunity which the occasion affords, of congratulating the Society on the successful completion of the labours and on the approaching return, of an Expedition, in which the Fellows individually, and as a body, have taken so strong an interest. A large portion of the observations contained in this number were made in southern latitudes never before reached by man; and nearly the whole in a part of the globe extremely difficult of access, but containing within itself a field for researches peculiarly needed for completing and perfecting, in the words of Halley, "the abstruse theory of terrestrial magnetism." In presenting to the Royal Society this portion of the results of an arduous enterprise, undertaken at their recommendation, it appears no improper departure from the usual tone of these communications, to allude very briefly to the causes which, under Providence, have conduced to its safe and successful issue;—to the admirable preparation and equipment of the vessels on the part of the Government,—to the high qualities of its Commander, manifested in conducting to its close, almost without an accident, and to the fullest accomplishment of its objects, a service of such duration and peculiar hazard,—and to the excellent spirit in which the Commander has been seconded by Captain Crozier, and supported by the officers and seamen who have been their worthy associates. Viewed merely as an expedition of discovery, its voyages must ever rank high in the annals of those maritime achievements of which our country is proud; but as a scientific expedition, which is its more proper character, as well as that in which the Royal Society must regard it with the greatest satisfaction, its best praise will undoubtedly be found in the record of its performances; and I hasten therefore to enter on that portion of them which I am now enabled to present to the Society. The peculiar feature in the magnetic survey of the portion of the southern hemisphere now under notice is, that it was conducted almost exclusively on board ship, the observations being subject to the disturbance occasioned by the ship's iron, in a part of the globe where the effect of this influence becomes excessive. The first consideration, therefore, must be to investigate the corrections which it is necessary to employ in compensation. The analysis of the effects produced by the iron of a vessel, and the theory of their corrections, have been given by the late M. Poisson, in a memoir read in 1838, and published in the Transactions of the Académie des Sciences, entitled "Mémoire sur les déviations de la Boussole produites par le fer des Vaisseaux." In cases in which the disturbance is due, partly to the magnetism induced by the earth's influence in the soft iron of the vessel, and partly to permanent magnetism acquired and retained by harder portions of her iron, the complexity of the source from whence the disturbance originates renders its correction very difficult. But in wood-built ships, when proper precautions are taken in regard to the place in the ship in which the instrument is used in observation, the disturbing influence is generally found to be that of induced magnetism alone: and in this case the correction may be obtained with tolerable facility*. The disturbance produced by the iron of the Erebus and Terror appearing to be of the latter class, I requested my friend Mr. Archibald Smith, Fellow of Trinity College, Cambridge, who in his academic course obtained the highest distinction conferred by the University, to draw out from M. Poisson's fundamental equations, applicable to induced magnetism, the most convenient and practical formulae for computing the corrections of the three magnetic * Since this communication was read to the Royal Society, Mr. Airy has favoured me with the following note:—"M. Poisson's deductions are founded on the assumption, that the phenomena of magnetism depend on the action of two fluids which attract each other, but which each repel other portions of fluid of the same kind: and that induction is caused by an alteration in the arrangement of these fluids among the particles of iron, produced by the attraction and repulsion of the earth's magnetic fluids. His fundamental equations in common language may be stated as follows: Horizontal force towards the ship's head, as disturbed, \( A' \times \{ \text{Undisturbed horizontal force to ship's head} \} + C \times \text{undisturbed vertical force.} \) Horizontal force towards the ship's head, as disturbed, \( B' \times \{ \text{Undisturbed horizontal force to ship's side} \} \) Vertical force, as disturbed... \( G \times \{ \text{Undisturbed horizontal force to ship's head} \} + K' \times \text{undisturbed vertical force.} \) These equations are the same as those obtained by Mr. Airy in the Philosophical Transactions, 1839, the first and second being the same as the two equations in page 184, and the third being the same as the last of the group of three equations in page 181. Mr. Airy's expressions however imply that \( G \) is equal to \( C \). The calculations in the sequel of this paper seem to show that in the Erebus \( G \) is greater than \( C \). Mr. Airy's deductions are founded on the assumption that each particle of iron is converted, by the earth's magnetic action, into a magnet with its length parallel to the direction of terrestrial magnetism." elements, for the use of nautical men, and of others who might be engaged in reducing magnetic observations made at sea. He has obligingly furnished me with the following memorandum: "At a given geographical position let $\phi$ represent the total magnetic intensity of the earth; $\theta$ the dip, which is considered positive when the north end of the needle dips below the horizontal plane, negative when it inclines above it; $\zeta$ the azimuth of the ship's head, or the angle between the principal section of the ship and the magnetic meridian, which is considered positive when the ship's head is to the west of the magnetic north, negative when to the east. Let $\phi'$, $\theta'$, $\zeta'$, be the values of the same elements shown by a needle whose centre is at a given place in the ship, when affected by the magnetism induced in the soft iron of the ship by the magnetism of the earth. M. Poisson has shown that if the dimensions of the needle are very small compared to its distance from the iron by which it is affected, the following equations are true; $$\phi' \cos \theta' \cos \zeta' = \phi [A' \cos \theta \cos \zeta + B \cos \theta \sin \zeta + C \sin \theta],$$ $$\phi' \cos \theta' \sin \zeta' = \phi [D \cos \theta \cos \zeta + E' \cos \theta \sin \zeta + F \sin \theta],$$ $$\phi' \sin \theta' = \phi [G \cos \theta \cos \zeta + H \cos \theta \sin \zeta + K' \sin \theta].$$ "In these equations, $A'$, $B$, $C$, $D$, $E'$, $F$, $G$, $H$, $K'$ are constants which depend only on the distribution of the iron in the ship relatively to the position of the needle and the plane of the horizon, and which continue the same for every geographical position of the ship, while the distribution of the iron within the ship, and the inclination of the ship to the horizon, remain the same. "If the centre of the needle is placed in the principal section of the ship, and the iron is symmetrically distributed on each side of that section, it will easily be seen that for values of $\zeta$ equal in magnitude and opposite in sign, the corresponding values of $\zeta'$ are equal in magnitude and opposite in sign, and the corresponding values of $\phi'$ and $\theta'$ are respectively equal in magnitude and the same in sign. These results necessarily imply that $B$, $D$, $F$ and $H$ are equal to zero. The equations in this case become $$\phi' \cos \theta' \cos \zeta' = \phi [A' \cos \theta \cos \zeta + C \sin \theta],$$ $$\phi' \cos \theta' \sin \zeta' = \phi . E' \cos \theta \sin \zeta,$$ $$\phi' \sin \theta' = \phi [G \cos \theta \cos \zeta + K' \sin \theta].$$ "If we divide each term by $\phi A'$ and put $\frac{C}{A'} = a$, $\frac{E'}{A'} = b$, $\frac{G}{A'} = c$, $\frac{K'}{A'} = d$, $$\frac{\phi'}{A'} \cos \theta' \cos \zeta' = \cos \theta \cos \zeta + a \sin \theta \ldots \ldots \ldots (1.)$$ $$\frac{\phi'}{A'} \cos \theta' \sin \zeta' = b \cos \theta \sin \zeta. \ldots \ldots \ldots \ldots (2.)$$ $$\frac{\phi'}{A'} \sin \theta' = c \cos \theta \cos \zeta + d \sin \theta. \ldots \ldots \ldots \ldots (3.)$$ "From these equations are derived the following: \[ \frac{\phi'}{A'\phi'} \cos \theta' = (\cos \zeta \cos \zeta' + b \sin \zeta \sin \zeta') \cos \theta + a \cos \zeta' \sin \theta, \ldots (4.) \] \[ \cos \zeta \sin \zeta' + a \tan \theta \sin \zeta' = b \sin \zeta \cos \zeta'; \ldots \ldots \ldots \ldots \ldots \ldots (5.) \] and representing \( \zeta - \zeta' \), or the deviation by \( \delta \), \[ \sin \delta = a \tan \theta \sin \zeta' + (1 - b) \cos \zeta' \sin \zeta \ldots \ldots \ldots \ldots (6.) \] \[ = \frac{2a}{1 + b} \tan \theta \sin \zeta' + \frac{1 - b}{1 + b} \sin (\zeta + \zeta') \ldots \ldots \ldots \ldots (7.) \] \[ \tan \zeta' = \frac{b \sin \zeta}{\cos \zeta + a \tan \theta} \ldots \ldots \ldots \ldots \ldots \ldots (8.) \] \[ c \cos \zeta + d \tan \theta = b \sin \zeta \cosec \zeta' \tan \theta' \ldots \ldots \ldots \ldots (9.) \] \[ = (\cos \zeta + a \tan \theta) \sec \zeta' \tan \theta' \ldots \ldots \ldots \ldots (10.) \] \[ = \sqrt{(\cos \zeta + a \tan \theta)^2 + b^2 \sin^2 \zeta' \tan \theta'} \ldots \ldots \ldots \ldots (11.) \] \[ \tan \theta' = \frac{c}{b} \left( \cos \zeta + \frac{d}{c} \tan \theta \right) \sin \zeta' \cosec \zeta \ldots \ldots \ldots \ldots (12.) \] \[ = c \cos \zeta + \frac{d}{c} \tan \theta \cos \zeta' \ldots \ldots \ldots \ldots (13.) \] \[ = c \cdot \frac{\cos \zeta + \frac{d}{c} \tan \theta}{\sqrt{(\cos \zeta + a \tan \theta)^2 + b^2 \sin^2 \zeta'}} \ldots \ldots \ldots \ldots (14.) \] "From these equations, and observations made at one geographical position with the ship's head on different azimuths, the constants \( a, b, c, d, A' \) may be determined, and the corrections of the affected elements at any other geographical position may be calculated. "a and \( b \) may be determined from observed deviations of the compass needle by means of equation (5.). A table of the deviations on each affected or compass course, and of the true magnetic course for each affected or compass course, may then be calculated by equations (6.) or (7.). In these equations \( \zeta \), which is an unknown quantity, occurs in the second term on the right-hand side; but the term is so small that an approximate value of \( \zeta \) may be used, and the error caused thereby neglected. This error is least in equation (7.), which is also the most convenient for calculation except on east and west courses. "To find the compass course for each true magnetic course, it will generally be sufficient to apply the deviations corresponding to the nearest true magnetic courses contained in the Table last described; but if the deviations are large, it will be better to construct a separate table by means of equation (8.). "c and \( d \) may be determined from the true dip and the affected dips observed on different courses by means of equation (11.), or more easily by means of (9.) and (10.); observing that the values of \( \zeta \) employed should be not observed values, but tabular..." values calculated in the manner described above. A table of the affected dip, and of the dip corrections on each course, may then be calculated from (14.), or more easily from (12.) and (13.); observing that (12.) must not be used when the ship's course is nearly north or south, and that (13.) must not be used when the ship's course is nearly east or west, and that the values of $\zeta$ should be tabular, not observed. "The constants may also be determined from observations of the total intensity, by means of the first four equations, and tables for the correction of the observed intensities may be constructed by means of these equations. For this purpose, equation (3.) should be used when the dip is large, and the others when the dip is small. "The values of $a$ and $b$ may be determined very readily, and probably with great accuracy, from observations of the horizontal intensity with the ship's head on the four principal compass courses. For if $H_n$, $H_w$, $H_s$, $H_e$ represent the values so observed, then $$a \tan \theta = \frac{H_n - H_s}{H_n + H_s}, \ldots \ldots \ldots \ldots \quad (15.)$$ $$b = \frac{H_w + H_e}{2\sqrt{H_w H_e}}, \ldots \ldots \ldots \ldots \quad (16.)$$ "If observations are made at equal intervals of time with the ship's head successively on the N., W., S., E., and N. points, the values of $a$ and $b$ thus determined will be independent of any regular increase or diminution of the intensity. If $n$, $w$, $s$, $e$ represent the number of vibrations in equal times, on the four principal courses, of the same horizontal needle, beginning to vibrate in the same arc, and corrected for temperature alone, $$a \tan \theta = \frac{n^2 - s^2}{n^2 + s^2}, \ldots \ldots \ldots \ldots \quad (17.)$$ $$b = \frac{w^2 + e^2}{2 n s}, \ldots \ldots \ldots \ldots \quad (18.)$$ "The true declination may be found independently of the dip and of the constant $a$, by means of observations of the true azimuth of the ship's head on two courses. Let $\psi$ represent the declination, which is considered positive when the north end of the needle is to the west of the true north, $\omega$ the true azimuth of the ship's head, which is positive when the ship's head is to the west of the true north; so that $\zeta = \omega - \psi$. And let $\omega_1$, $\zeta'_1$ and $\omega_2$, $\zeta'_2$ represent the observed values of $\omega$ and $\zeta$ on the two courses, $$\tan \left( \psi - \frac{\omega_1 + \omega_2}{2} \right) = \frac{b \sin (\zeta'_1 + \zeta'_2)}{2 \sin \zeta'_1 \sin \zeta'_2 - b \sin (\zeta'_1 - \zeta'_2) \cot \frac{\omega_1 - \omega_2}{2}}.$$ "If the observations are made with the ship's head on exactly opposite courses, $\omega_1 - \omega_2 = 180^\circ$; and we have $$\tan (\omega_1 - \psi) = \frac{2 \sin \zeta'_1 \sin \zeta'_2}{b \sin (\zeta'_1 + \zeta'_2)} \times 2.$$ if at equal azimuths on each side of the magnetic north, \[ \psi = \frac{\omega_1 + \omega_2}{2}. \] "The formula fails if \( \zeta'_1 + \zeta'_2 = 180^\circ \), the denominator becoming zero; the true value of \( \tan \left( \psi - \frac{\omega_1 + \omega_2}{2} \right) \) in that case is \[ \frac{b}{\sin 2 \zeta'_1 + b \cos 2 \zeta'_1 \cot \frac{\omega_1 - \omega_2}{2}}. \] --- **Corrections for the Erebus.**—We will seek in the first instance the values of the constants \( a \) and \( b \), because they are those which can be obtained with the greatest degree of exactness, being derived from observations with the compass needle, which are made with greater precision than those with the inclination or intensity needles. Before the Expedition quitted England, a suitable position in the midship line was chosen for magnetic observations on board ship, and the effect of the ship's attraction on a standard compass placed in that spot, was ascertained by observations with the ship's head turned successively on each of the thirty-two principal points. This was done in September 1839 at Gillingham near Chatham, where \( \theta \), or the Inclination, was at that epoch \( 69^\circ 05' \). The observations in the Erebus gave results as follows: | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | |------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------| | N. | +0° 06 | W. | +4° 19 | S. | +0° 28 | E. | -3° 42 | | N. by W. | +1° 12 | W. by S. | +4° 40 | S. by E. | -0° 19 | E. by N. | -4° 53 | | N.N.W. | +2° 01 | W.S.W. | +4° 03 | S.S.E. | -0° 48 | E.N.E. | -3° 46 | | N.W. by N. | +2° 10 | S.W. by W. | +3° 24 | S.E. by S. | -1° 23 | N.E. by E. | -3° 18 | | N.W. | +3° 03 | S.W. | +2° 45 | S.E. | -1° 53 | N.E. | -2° 59 | | N.W. by W. | +3° 28 | S.W. by S. | +2° 08 | S.E. by E. | -2° 21 | N.E. by N. | -2° 16 | | W.N.W. | +3° 51 | S.S.W. | +1° 34 | E.S.E. | -2° 50 | N.N.E. | -1° 39 | | W. by N. | +4° 09 | S. by W. | +0° 52 | E. by S. | -3° 17 | N. by E. | -0° 49 | We perceive by this Table that, allowance being made for slight irregularities in the observations, the masses of iron which acted on the compass needle of the Erebus in its standard position were distributed symmetrically, or very nearly so, on either side of the vertical plane, passing through the longitudinal midship section. We may therefore safely employ, in computing the corrections, the more simple formulæ which are applicable under this condition. To obtain the constants \( a \) and \( b \) of these formulæ we may arrange equations on the several points, from the observations in the Table, of the form \[ \cos \zeta \sin \zeta' - b \sin \zeta \cos \zeta' = -a \tan \theta \sin \zeta'. \] * Reports of the British Association, 1838. N. by W. \( \cdot1905 - \cdot2115 b = - 0\cdot510 a \) N.N.W. \( \cdot3482 - \cdot3834 b = - 1\cdot001 a \) N.W. by N. \( \cdot4481 - \cdot4916 b = - 1\cdot454 a \) N.W. \( \cdot4727 - \cdot5258 b = - 1\cdot850 a \) N.W. by W. \( \cdot4193 - \cdot4798 b = - 2\cdot175 a \) N.N.W. \( \cdot2954 - \cdot3626 b = - 2\cdot417 a \) W. by N. \( \cdot1212 - \cdot1936 b = - 2\cdot566 a \) \(+ 2\cdot2954 - 2\cdot6483 b = - 11\cdot973 a \) . . . . (1.) W. by S. \( - \cdot2689 + \cdot1876 b = - 2\cdot566 a \) W.S.W. \( - \cdot4130 + \cdot3423 b = - 2\cdot417 a \) S.W. by W. \( - \cdot5021 + \cdot4427 b = - 2\cdot175 a \) S.W. \( - \cdot5233 + \cdot4754 b = - 1\cdot850 a \) S.W. by S. \( - \cdot4729 + \cdot4359 b = - 1\cdot454 a \) S.S.W. \( - \cdot3574 + \cdot3301 b = - 1\cdot001 a \) S. by W. \( - \cdot1919 + \cdot1768 b = - 0\cdot510 a \) \(- 2\cdot7295 + 2\cdot3908 b = - 11\cdot973 a \) . . . . (2.) S. by E. \( \cdot1915 - \cdot1860 b = 0\cdot510 a \) S.S.E. \( \cdot3563 - \cdot3366 b = 1\cdot001 a \) S.E. by S. \( \cdot4693 - \cdot4451 b = 1\cdot454 a \) S.E. \( \cdot5161 - \cdot4832 b = 1\cdot850 a \) S.E. by E. \( \cdot4900 - \cdot4489 b = 2\cdot175 a \) E.S.E. \( \cdot3953 - \cdot3459 b = 2\cdot417 a \) E. by S. \( \cdot2462 - \cdot1888 b = 2\cdot566 a \) \(+ 2\cdot6647 - 2\cdot4345 b = 11\cdot973 a \) . . . . (3.) E. by N. \( - \cdot1088 + \cdot1939 b = 2\cdot566 a \) E.N.E. \( - \cdot2967 + \cdot3625 b = 2\cdot417 a \) N.E. by E. \( - \cdot4214 + \cdot4789 b = 2\cdot175 a \) N.E. \( - \cdot4732 + \cdot5252 b = 1\cdot850 a \) N.E. by N. \( - \cdot4494 + \cdot4888 b = 1\cdot454 a \) N.N.E. \( - \cdot3492 + \cdot3780 b = 1\cdot001 a \) N. by E. \( - \cdot1908 + \cdot2050 b = 0\cdot510 a \) \(- 2\cdot2895 + 2\cdot6323 b = 11\cdot973 a \) . . . . (4.) From (1.) and (4.), changing the signs of (1.) and summing, we have \(- 4\cdot5849 + 5\cdot2806 b = + 23\cdot946 a \) . . . . . . . . . . (5.) From (2.) and (3.), changing the signs of (3.) and summing, we have \(- 5\cdot3942 + 4\cdot8253 b = - 23\cdot946 a \); . . . . . . . . . . (6.) whence \( 10\cdot1059 b = + 9\cdot9791 \); and \( b = + 0\cdot9875 \); From (5.) and (6.), changing the signs of (6.) and summing, we have \[47.892 \cdot a = 4.553 \cdot b + 8.093; \quad a = + 0.0263.\] We have also the equations at east and west; East . . . . \(2.617 \cdot a = + 0.0645\) West . . . . \(-2.617 \cdot a = - 0.0753;\) whence \[a = \frac{1.398}{5.234} = + 0.0267;\] or including the observations at east and west in the general sum, we have \[a = + 0.0264.\] After the arrival of the Expedition at Hobarton, and before it sailed to the Antarctic Circle, a similar series of observations was made in the Erebus, on the 29th October 1840, and again repeated on her return to Hobarton the following autumn, viz. on the 29th June 1841. The south end of the needle being now the one which dipped below the horizon (\(\theta\) being \(-70^\circ 40'\)), the deviation of the compass was found to take place in the contrary direction to that which had been observed at Gillingham, the disturbance being towards the west as the ship's head went round from north by east to south, and towards the east as her head passed from south through west to north. The line of no deviation was not found to correspond accurately with the north and south points of the compass on either of the occasions at Hobarton, but in 1840 coincided more nearly with the north by west and south by east, and in 1841 with the north by east and south by west. We may perhaps ascribe with probability irregularities of this nature to slight modifications in the distribution of the iron at different periods, which we cannot but view as of not unlikely occurrence; for example, such as might be occasioned by the ship being secured at different times by the starboard or the larboard chain cable. In looking through the observations of the Erebus, it is evident that there was no systematic or constant deviation of the plane of the ship's attraction from that of her principal section; but that the points of no disturbance were sometimes a little on the one side, and sometimes a little on the other, of the north and south points. It appears, therefore, not improper to class these irregularities with those others of accidental occurrence which occasion small discordances in partial results, and are usually ranged under the general technical head of errors of observation. If, further, we compare generally the deviations in 1840 with those of April 1841, the latter appear systematically rather the more considerable in amount. Viewed as a single fact, this circumstance might be regarded simply as indicating that some change had taken place in the interim in the arrangement and distribution of the ship's iron, and an easy and natural explanation might appear to be afforded. It is however one of several facts which have presented themselves in the course of a careful examination of the observations of the first two years of Captain Ross's expedition, which seem to point to the possibility of a somewhat different cause, viz. that when a ship changes her magnetic latitude, the corresponding change in the magnetism of the ship, or more strictly in that portion of it which is derived from induction, follows, but does not always, or altogether, take place instantaneously. It would accord with this supposition, that the disturbance of the compass should be less in the Erebus on her first arrival at Hobarton in 1840, than on her return there in 1841, because in 1840 she had recently passed through the lowest magnetic latitudes, and in 1841 she came immediately from the highest. The observations in 1840 give a less value for $a \tan \theta$ than those of 1841, and taking the dip at Hobarton as the value of $\theta$, to which the induced magnetism of the ship on both occasions should strictly correspond, we should have a less value for $a$ in 1840 than in 1841; whereas if with the same dip we take a mean between the disturbances of the compass on the first arrival and on the return, by which we may be conceived to neutralize in a great measure the temporary influences which have been supposed, we find the value of $a$ to be almost identical with the result of the former experiments at Gillingham. From this accordance in the value of the constant in dips which differ so greatly as from $+69^\circ$ to $-70^\circ$, we should infer the probability,—first, that the local attraction of the Erebus was due to induced magnetism alone, the influence of any portions of iron which, in the strict sense of the term, were permanently magnetic, being insensible;—and secondly, that no material change affecting the standard compass had taken place in the distribution of her iron. These inferences are by no means inconsistent with the supposition above suggested, that some portions of her iron might be of a quality intermediate between that of perfectly soft iron which undergoes instantaneous change, and that of iron which acquires permanent magnetism, and that such portions should be liable, in regard to their magnetic condition, to be more or less in arrear of the ship's magnetic position. I abstain from entering further into this question at present, because a fitter opportunity of doing so will be afforded when the whole of the observations of the Expedition shall be collected, including those which have yet to be made at Rio de Janeiro on the return from the high latitudes of the south, and in England after passing through the low magnetic latitudes of the equatorial region. Should it prove that the induced magnetism of a ship due to any particular dip requires time for its full development, more or less according to the various quality of her iron, the corrections to be applied may possibly in some ships be considerably complicated thereby: fortunately in the Erebus the difference in the amount of the disturbance on the two occasions at Hobarton, which gave rise to this discussion, is not of any serious consequence; and we may employ without any material inconvenience for our present purpose the mean of the two series as applicable generally between their respective dates, for which interval we specially desire the corrections. Employing the same formula as before, and forming equations from the observations on the twenty-eight points, being all the points excepting the north, south, east and west, we obtain \[10 \cdot 1036 b = +9 \cdot 9673\] \[b = +0 \cdot 9865;\] and from the sum of the thirty equations, including those at east and west, we have \[+57 \cdot 89 a = +1 \cdot 0439 + 0 \cdot 537 b,\] \[a = \frac{1 \cdot 0439 + 0 \cdot 5297}{57 \cdot 89} = +0 \cdot 0272.\] On the passage from Hobarton to the Antarctic Circle, the Expedition stopped at Auckland Island for the purpose of observing on the term day of November 1840. The Erebus was not swung at this station, but with the value of \(d\) observed on shore \(-73^\circ 10'\), and the declination observed on board whilst at anchor, with the ship's head on the east and west points, and on the E.N.E. and W.N.W. points, we may obtain a satisfactory value for \(a\). On the supposition of the symmetrical distribution of the iron on either side of the longitudinal midship section, the deviation occasioned by it should be the same in amount, but with opposite signs, at east and west, and also at E.N.E. and W.N.W.; the amount, however, being slightly different at east and west from that at E.N.E. and W.N.W. From the observations at east and west we have \[\psi' = -12^\circ 52' \text{ at east, and } \psi' = -22^\circ 55' \text{ at west};\] \[\psi = \frac{\psi' + \psi'}{2} = -17^\circ 53'5,\text{ and}\] \[d = \pm 5^\circ 01'5; \text{ whence } a = +0 \cdot 0265.\] From the observations at E.N.E. and W.N.W., \[ \psi = -13^\circ 36' \text{ at E.N.E., and } -22^\circ 06' \text{ at W.N.W.}; \] \[ \psi = -17^\circ 51'; \quad \zeta' = 67^\circ 30', \text{ and } \zeta = 63^\circ 15'; \text{ whence } a = 0.0261. \] The mean of the two pairs of observations gives \( a = +0.0263 \). Whilst within the Antarctic Circle only a single opportunity occurred of observing the inclination otherwise than on board, and thus of obtaining \( a \) from \( a \tan \theta \) by having an assured value of \( \theta \). This was on the 8th of January 1841, in lat. \(-68^\circ 30'\), long. \(176^\circ 35'\), where the inclination observed on the ice with a needle in which the observation was complete by the reversal of the poles, was found to be \(-83^\circ 35'\). The declination was observed on board on the same afternoon and following morning, as nearly as could be in the same geographical position, with the ship's head on several points, from which we may select for a determination of \( a \) those nearest to the east and west points. We have then the following observations: 1. At W. \( \frac{3}{4} \) N. \( \psi = -46^\circ 02' \) 2. At W. by S. \( \psi = -46^\circ 32' \) 3. At W. by S. \( \frac{1}{2} \) S. \( \psi = -47^\circ 17' \) 4. At E. \( \frac{3}{4} \) N. \( \psi = -20^\circ 51' \) 5. At E. by S. \( \frac{1}{2} \) S. \( \psi = -19^\circ 58' \) 6. At E. by S. \( \frac{3}{4} \) S. \( \psi = -20^\circ 22' \) From 1. and 4. we have \( \psi = \frac{\psi_1 + \psi_4}{2} = -33^\circ 27'5 \) From 3. and 5. we have \( \psi = \frac{\psi_3 + \psi_5}{2} = -33^\circ 37'5 \) Hence \[ \delta_1 = -12^\circ 29'5 \] \[ \delta_2 = -12^\circ 59'5 \] \[ \delta_3 = -13^\circ 44'5 \] \[ \delta_4 = +12^\circ 41'5 \] \[ \delta_5 = +13^\circ 34'5 \] \[ \delta_6 = +13^\circ 10'5; \] and having thereby the values of \( \zeta \), as we have those of \( \zeta' \) by observation, we obtain \[ a_1 = +0.0249 \] \[ a_2 = +0.0274 \] \[ a_3 = +0.0274 \] \[ a_4 = +0.0259 \] \[ a_5 = +0.0275 \] \[ a_6 = +0.0266 \] Means . . . \( +0.0266 \) The deviation of the compass observed on board the Erebus during the stay of the Expedition at Christmas Harbour, Kerguelen Island, in July 1840, when the ship's head was on the N.E., S.E., N.W., and S.W. points, and at the points on either side of those points, viz. N.E. by N., N.E. by E., S.E. by S., S.E. by E., &c., will furnish an additional determination of the value of \( b \): Employing these values of $\zeta'$ and $\zeta$ in the formula $$\cos \zeta \sin \zeta' - b \cos \zeta' \sin \zeta + a \tan \theta \sin \zeta' = 0,$$ and eliminating $a \tan \theta \sin \zeta'$, we have $$5.7471 b = 5.6233; \quad b = .9785.$$ Collecting now in one view the values of $a$, we have as follows: 1. From the observations at Gillingham near Chatham $a = +.0264$ 2. From the observations at Hobarton $a = +.0272$ 3. From the observations at Auckland Island $a = +.0263$ 4. From the observations in lat. $-68^\circ 30'$, long. $176^\circ 35'$ $a = +.0267$ Mean $+ .0267$ From this near accordance in the values of $a$, obtained in dips varying from $+ 69^\circ 05'$ to $- 83^\circ 35'$, we are warranted in regarding the local attraction in the Erebus as due to induced magnetism; and in employing the formulae derived from M. Poisson's fundamental equations, which are based on the hypothesis of induced magnetism only, in computing corrections for the observations made on board that ship. For the value of $b$ we have From the observations at Gillingham $b = +.9874$ From the observations at Hobarton $b = +.9865$ From the observations at Kerguelen Island $b = +.9785$ Mean $+.9841$ With these values of $a$ and $b$, a table of double entry was formed, having for arguments $\zeta'$ and $\theta$; $\zeta'$ being the compass direction of the ship's head when an azimuth was observed, and $\theta$ the inclination taken from the chart formed from the observations of that element on board ship, corrected in the manner that will be shown hereafter; the corrections for the ship's local attraction in the general Table of Declinations observed in the Erebus have been taken from the Table thus formed. In geographical positions, where the inclination made a very near approximation to $-90^\circ$, and when azimuths observed on the same day at places sufficiently near to each other included observations on the east and west points, or on points but little removed from them, on which the corrections for the deviation might have the same, or nearly the same, value, but with opposite signs, the inclination with which the corrections have been computed has been derived from the azimuths themselves in preference to being taken from the chart. In such cases, and when $a$ and $b$ have been elsewhere satisfactorily determined for the ship, the amount of disturbance which her iron produces on the compass needle furnishes itself a measure of the inclination, exceeding in precision that of the dipping needle used on board. If the ship's magnetism should have already conformed to the terrestrial dip, the inclination corresponding to the disturbance of the compass is that belonging to the geographical position, and the ship herself, with merely her compass needle, would become in such rare situations an inclinometer of great delicacy. But if the change in the magnetism of the ship from that due to a former magnetic locality be not yet fully developed, the inclination thus furnished by the compass needle is on that account also preferable to that which might be taken from the chart, or to the dip observed with the dipping needle either on board or on shore, for the correction of other azimuths observed at the same time. Whenever the inclination used for the declination corrections has been thus derived, a notice is annexed in its proper place in the general table. It may be useful to give an example, and I select for that purpose the observations on the afternoon of the 16th February 1841, when, from the amount of the declination ($-112^\circ$ or $-113^\circ$), the Expedition had without doubt penetrated to the south of the latitude of the magnetic pole; the particular observations are as follow: | Latitude | Longitude | Ship's head. | Declination observed. | |----------|-----------|--------------|-----------------------| | -76° 35' | 166° 17' | E. by S. $\frac{1}{2}$ s. | $-64^\circ 23'$ | | 76° 36' | 166° 17' | N.N.W. $\frac{1}{2}$ w. | $-136^\circ 19'$ | | -76° 36' | 166° 17' | W.N.W. | $-150^\circ 04'$ | | -76° 36' | 166° 16' | N.W. by N. | $-138^\circ 24'$ | | -76° 36' | 166° 16' | W. | $-158^\circ 51'$ | | -76° 36' | 166° 16' | W. by S. $\frac{1}{2}$ s. | $-156^\circ 58'$ | | -76° 36' | 166° 16' | S.W. $\frac{1}{4}$ w. | $-156^\circ 05'$ | | -76° 36' | 166° 17' | S.W. by N. | $-154^\circ 06'$ | | -76° 36' | 166° 17' | S.W. $\frac{1}{4}$ s. | $-142^\circ 54'$ | | -76° 37' | 166° 16' | E.N.E. | $-67^\circ 01'$ | | -76° 37' | 166° 16' | E. by S. | $-67^\circ 53'$ | | -76° 37' | 166° 16' | E. by S. | $-66^\circ 32'$ | | -76° 37' | 166° 16' | E.S.E. | $-73^\circ 45'$ | | -76° 37' | 166° 35' | S.E. by E. | $-73^\circ 40'$ | From the observations at W., and E. by S., we have the approximate values of $\psi = \frac{\psi + \psi'}{2} = -113^\circ 01'$; $\delta$ at W. = $-45^\circ 50'$; tan $\theta = \frac{\sin \delta}{0.0267}$; whence $\theta = -87^\circ 52'$. With this approximate inclination we compute $\delta$ at E. by $S. = +45^\circ 04'$; and with this correction, and the same observations as before, we have more precisely $$\psi = -112^\circ 38' ; \delta \text{ at W.} = -46^\circ 13' ; \text{ and } \theta = -87^\circ 53'.$$ Substituting this value of $\theta$ in the formula $$\sin \delta = \frac{2a}{1+b} \tan \theta \sin \zeta' + \frac{1-b}{1+b} \sin (\zeta' + \zeta),$$ we have the corrections and the corrected declination as follows: | Direction | Correction | $\psi'$ | $\psi$ | |-----------|------------|--------|-------| | E. by S. $\frac{1}{2}$ S. | Correction $-46^\circ 03'$ | $-64^\circ 23'$ | $-108^\circ 26'$ | | N.N.W. $\frac{1}{2}$ W. | Correction $+19^\circ 46'$ | $-136^\circ 19'$ | $-116^\circ 33'$ | | N.N.W. | Correction $+41^\circ 38'$ | $-150^\circ 04'$ | $-108^\circ 26'$ | | N.W. by N. | Correction $+23^\circ 31'$ | $-138^\circ 24'$ | $-114^\circ 53'$ | | W. | Correction $+46^\circ 13'$ | $-158^\circ 51'$ | $-112^\circ 38'$ | | W. by S. $\frac{1}{2}$ S. | Correction $+44^\circ 03'$ | $-156^\circ 58'$ | $-112^\circ 55'$ | | S.W. $\frac{1}{4}$ W. | Correction $+33^\circ 04'$ | $-156^\circ 05'$ | $-123^\circ 01'$ | | S.W. by W. | Correction $+37^\circ 32'$ | $-154^\circ 06'$ | $-116^\circ 34'$ | | S.W. $\frac{1}{4}$ S. | Correction $+29^\circ 45'$ | $-142^\circ 54'$ | $-113^\circ 09'$ | | E.N.E. | Correction $-41^\circ 38'$ | $-67^\circ 01'$ | $-108^\circ 39'$ | | E. by S. | Correction $-45^\circ 19'$ | $-66^\circ 32'$ | $-111^\circ 51'$ | | E. by S. | Correction $-45^\circ 19'$ | $-67^\circ 53'$ | $-113^\circ 12'$ | | E.S.E. | Correction $-42^\circ 18'$ | $-73^\circ 45'$ | $-116^\circ 03'$ | | S.E. by E. | Correction $-37^\circ 32'$ | $-73^\circ 40'$ | $-111^\circ 12'$ | Mean . . . $-113^\circ 23'$ On comparing the values of $\psi$ thus obtained from the observations on the easterly points, with those on the westerly points, it is evident that the remaining differences in the individual results are not occasioned by faults in the corrections, but that they are actual differences in the observations of azimuth. In the extreme circumstances to which the Expedition had attained, when by reason of the great amount of dip, the terrestrial force acting on the compass needle, and directing it to one part of the horizon in preference to another, was reduced to $\frac{1}{27}$th part of the whole amount of the terrestrial magnetic force in the same locality, the degree of accordance which was still preserved assuredly surpasses expectation*. The result at S.W. $\frac{1}{4}$ W. is the only one which presents an excessive discordance; and after a careful examination of the whole of the observations which the general table contains, it must be regarded * The compass used in the Erebus was the first of the new naval compasses made under the direction of a Committee appointed by the Admiralty "for the improvement of ships' compasses." The magnet was composed of several thin plates of clock-spring suitably arranged, giving very considerable magnetic force, with a suspension improved both in mode and materials. This compass appears to have answered remarkably well in the very trying circumstances in which it was employed. Captain Ross was himself the Chairman of the Committee, which gave its services gratuitously: the other members were Captain Beaufort, R.N., Mr. Christie, Major Jervis, Captain Edward Johnson, R.N., and Lieut.-Colonel Sabine. as a case of very unusual observation error. Were we to omit this result, the mean would become $-112^\circ 39'$. When the corrections for local attraction become so great, it is necessary to be very accurate in noting the direction of the ship's head at the same instant that the azimuth is observed, as at the points where the changes of $\delta$ for changes of $\zeta'$ are very great, an error of a degree in the direction of the ship's head will make nearly the same error in the correction; on such occasions therefore the result is liable to an additional source of observation error of serious magnitude. We have seen that when the inclination is $-87^\circ 53'$, the sum of the deviations at east and west amounted to $92^\circ 26'$; with $10'$ increase in the dip, their joint amount would have become $126^\circ 52'$. The scale which the compass needle presents for the deduction of the inclination is consequently a very large one, when the inclination is so great as that which we are now considering; and it continues to increase in magnitude, until the compass ceases altogether to indicate the direction of the horizontal component of the terrestrial force, and points unchangingly, under every alteration of the ship's head, to the direction of the general resultant of the ship. The terrestrial dip observed with a dipping-needle on board on the 16th of February, and corrected for the ship's attraction, was $-88^\circ 20'$; that corresponding to the magnetism of the ship was, as we have seen, $-87^\circ 53'$, being a little in arrear, in a magnetic sense, of her then position. For the constants $c$ and $d$ in the formula for the correction of the inclination, we have to take into account, in the first instance, a series of observations of the inclination with the ship's head successively on the sixteen principal points of the compass, made on board the Erebus at Hobarton in November 1840, before her departure for the Antarctic Circle, and a similar series made at the same place in June 1841 on her return from the south. The inclination observed on shore was $-70^\circ 40'$. | Ship's head by compass | Inclination observed | Ship's head by compass | Inclination observed | |------------------------|---------------------|------------------------|---------------------| | | 1840. | 1841. | Mean. | | N. | $-71^\circ 52'$ | $-71^\circ 59'$ | $-71^\circ 55\cdot5$ | | N.N.W. | $-71^\circ 55'$ | $-72^\circ 00'$ | $-71^\circ 57\cdot5$ | | N.W. | $-72^\circ 03'$ | $-71^\circ 45'$ | $-71^\circ 54\cdot0$ | | W.N.W. | $-71^\circ 30'$ | $-71^\circ 24'$ | $-71^\circ 27$ | | W. | $-71^\circ 16'$ | $-70^\circ 55'$ | $-71^\circ 05\cdot5$ | | W.S.W. | $-70^\circ 55'$ | $-70^\circ 30'$ | $-70^\circ 42\cdot5$ | | S.W. | $-70^\circ 20'$ | $-69^\circ 56'$ | $-70^\circ 08\cdot5$ | | S.S.W. | $-70^\circ 07'$ | $-69^\circ 44'$ | $-69^\circ 55\cdot5$ | | S. | $-69^\circ 49'$ | $-69^\circ 19'$ | $-69^\circ 34$ | | S.S.E. | $-70^\circ 00'$ | $-69^\circ 41'$ | $-69^\circ 50\cdot5$ | | S.E. | $-70^\circ 22'$ | $-70^\circ 04'$ | $-70^\circ 13$ | | E.S.E. | $-70^\circ 45'$ | $-70^\circ 33'$ | $-70^\circ 39$ | | E. | $-70^\circ 58'$ | $-71^\circ 08'$ | $-71^\circ 03$ | | E.N.E. | $-71^\circ 33'$ | $-71^\circ 32'$ | $-71^\circ 32\cdot5$ | | N.E. | $-71^\circ 35'$ | $-71^\circ 57'$ | $-71^\circ 46$ | | N.N.E. | $-71^\circ 42'$ | $-71^\circ 56'$ | $-71^\circ 49$ | Employing for the observations between N.N.W. and S.S.W., and N.N.E. and S.S.E. the formula $$c \cos \zeta + d \tan \theta = b \sin \zeta \csc \zeta' \tan \theta',$$ and for the other points \[ c \cos \zeta + d \tan \theta = (\cos \zeta + a \tan \theta) \sec \zeta' \tan \theta', \] and using the values of \( \zeta \) computed by means of the constants \( a \) and \( b \) already determined, we have the following equations: \[ \begin{align*} N. & \quad +1'0000c - 2'850d = -2'830 \\ N.N.W. & \quad +9327c - 2'850d = -2'845 \\ N.W. & \quad +7351c - 2'850d = -2'868 \\ N.S.W. & \quad +4418c - 2'850d = -2'848 \\ W. & \quad +0761c - 2'850d = -2'864 \\ W.S.W. & \quad -3139c - 2'850d = -2'889 \\ S.W. & \quad -6617c - 2'850d = -2'922 \\ S.S.W. & \quad -9110c - 2'850d = -2'888 \\ S. & \quad -1'0000c - 2'850d = -2'888 \\ S.S.E. & \quad -9110c - 2'850d = -2'906 \\ S.E. & \quad -6617c - 2'850d = -2'902 \\ E.S.E. & \quad -3139c - 2'850d = -2'880 \\ E. & \quad +0761c - 2'850d = -2'858 \\ E.N.E. & \quad +4418c - 2'850d = -2'862 \\ N.E. & \quad +7351c - 2'850d = -2'845 \\ N.N.E. & \quad +9327c - 2'850d = -2'822 \end{align*} \] Summing these equations, \( c \) is eliminated, and \( d = \frac{45'917}{45'604} = 1'0069 \); and changing the signs in the equations from W. to E.S.E. inclusive and summing, we have \[ c = \frac{+361}{9'9924} = +0'361. \] A similar series of observations made at Auckland Island on the passage from Hobarton to the Antarctic Circle, furnishes values of \( c \) and \( d \) differing but slightly from the preceding. The inclination observed on shore was \( -73^\circ 10' \). | Ship's head by compass | Inclination observed | |------------------------|---------------------| | N. | -74° 24' | | N.N.W. | -74° 34' | | N.N.E. | -74° 09' | | N.W. | -74° 16' | | N.E. | -74° 13' | | W.N.W. | -74° 08' | | E.N.E. | -73° 43' | | W. | -73° 32' | Treating these observations in a similar manner to those at Van Diemen Island, we obtain \[ c = +0'045; \quad d = +1'0039. \] Giving double weight to the observations at Hobarton, as representing a double series, we have \( c = +0'039 \); and \( d = +1'006 \). With these values of the constants in the formulæ \[ \tan \theta' = \frac{c}{b} \left( \frac{d}{c} \tan \theta + \cos \zeta \right) \sin \zeta' \cosec \zeta, \text{ from N.E to S.E., and from N.W. to S.W.} \] \[ \tan \theta' = c \left( \frac{\frac{d}{c} \tan \theta + \cos \zeta}{a \tan \theta + \cos \zeta} \right) \cos \zeta' \text{ on other points,} \] a table of double entry was formed for the corrections of the observations of in- clination in the Erebus, having for arguments $\theta$ and $\zeta'$; the corrections in the general Table of the inclination observations were thus obtained. We may compute the value of the remaining constant $A'$ from the variations of the magnetic intensity observed on board the Erebus at Hobarton with Mr. Fox's intensity apparatus, with the ship's head on the sixteen principal points of the compass; two series of such observations were made, one in October 1840 with needle R. F. 4, the other in July 1841 with needle R. F. 5; expressing the value of the intensity on shore by $1.82 = \phi$, the several values on board ship are shown in the following Table: | Ship's head by compass | Intensity | |------------------------|-----------| | | October 1840 | July 1841 | Means | | N. | 1.792 | 1.806 | 1.799 = $\phi'$ | | N.N.E. | 1.787 | 1.803 | 1.795 = $\phi'$ | | N.N.W. | 1.807 | 1.818 | 1.812 = $\phi'$ | | N.E. | 1.789 | 1.813 | 1.801 = $\phi'$ | | N.W. | 1.803 | 1.816 | 1.809 = $\phi'$ | | E.N.E. | 1.816 | 1.821 | 1.818 = $\phi'$ | | W.N.W. | 1.830 | 1.832 | 1.831 = $\phi'$ | | E. | 1.828 | 1.823 | 1.826 = $\phi'$ | | W. | 1.832 | 1.829 | 1.830 = $\phi'$ | | E.S.E. | 1.830 | 1.839 | 1.830 = $\phi'$ | | W.S.W. | 1.848 | 1.837 | 1.842 = $\phi'$ | | S.E. | 1.842 | 1.853 | 1.848 = $\phi'$ | | S.W. | 1.862 | 1.855 | 1.858 = $\phi'$ | | S.S.E. | 1.858 | 1.859 | 1.859 = $\phi'$ | | S.S.W. | 1.863 | 1.857 | 1.860 = $\phi'$ | | S. | 1.864 | 1.864 | 1.864 = $\phi'$ | Employing the formula $$\frac{\phi'}{A'} \sin \theta' = c \cos \theta \cos \zeta + d \sin \theta$$ with the values of $\theta'$ and $\zeta$ computed by means of the constants $a$, $b$, $c$ and $d$, already deduced, and with the observed values of $\phi$, $\theta$, and $\phi'$, we have $A'$ as follows: - At N. $A' = 0.997$ - At N.N.E. and N.N.W. $A' = 0.996$ - At N.E. and N.W. $A' = 0.998$ - At E.N.E. and W.N.W. $A' = 0.993$ - At E. and W. $A' = 0.998$ - At E.S.E. and W.S.W. $A' = 1.002$ - At S.E. and S.W. $A' = 1.000$ - At S.S.E. and S.S.W. $A' = 1.002$ - At S. $A' = 1.002$ Mean... 0.999 We obtain the same result if we employ the observed values of $\theta'$ instead of the computed values; in this case the inclination and total intensity being both furnished at the several points by observation with Mr. Fox's apparatus, we have the ratios of the horizontal intensity $\frac{\phi' \cos \theta'}{\phi \cos \theta}$ on board as follows: \[ \begin{align*} N. & = 0.9262; \\ N.N.E. & = 0.9308; \\ N.N.W. & = 0.9340; \\ E. & = 0.9838; \\ W. & = 1.0800; \\ S. & = 1.0615; \\ S.S.W. & = 1.0432; \\ E.S.E. & = 1.0084; \end{align*} \] From which by the formula \[ H = A' (\cos \zeta \cos \zeta' + b \sin \zeta \sin \zeta' + a \tan \theta \cos \zeta'), \] we have \[ \begin{align*} \text{At N.} & \quad A' = \frac{0.9262}{0.9239} = 1.003 \\ \text{At N.N.E. and N.N.W.} & \quad A' = \frac{0.9308}{0.9270} = 1.004 \\ \text{At N.E. and N.W.} & \quad A' = \frac{0.9340}{0.9374} = 0.996 \\ \text{At E.N.E. and W.N.W.} & \quad A' = \frac{0.9608}{0.9555} = 1.006 \\ \text{At E. and W.} & \quad A' = \frac{0.9838}{0.9917} = 0.992 \\ \text{At E.S.E. and W.S.W.} & \quad A' = \frac{1.0084}{1.0122} = 0.996 \\ \text{At S.E. and S.W.} & \quad A' = \frac{1.0432}{1.0433} = 0.999 \\ \text{At S.S.E. and S.S.W.} & \quad A' = \frac{1.0615}{1.0673} = 0.994 \\ \text{At S.} & \quad A' = \frac{1.0800}{1.0761} = 1.004 \\ \end{align*} \] \[ A' = 0.999 \text{ Mean.} \] The correction for the ship's attraction in the general table of the intensities observed in the Erebus, have been computed with this value of $A'$ used in the formula \[ A' c \left( \frac{d}{c} \tan \theta + \cos \zeta \right) \cos \theta \csc \theta'; \] $\theta$ being taken from the chart formed from the observations of the inclination, and $\theta'$ and $\zeta'$ from the tables with the arguments $\theta$ and $\zeta'$. Deduction of the Constants in Her Majesty's Ship Terror.—For these we have, in the first place, the observations at Gillingham, in September 1839, as follows: \[ \theta = 69^\circ 05' \] | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | |------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------| | N. | +0°11 | W. | +5°55 | S. | -0°8 | E. | -5°22 | | N. by W. | +1°35 | W. by S. | +5°17 | S. by E. | -0°51 | E. by N. | -5°50 | | N.N.W. | +2°31 | W.S.W. | +4°39 | S.S.E. | -1°42 | E.N.E. | -5°22 | | N.W. by N. | +3°9 | S.W. by W. | +3°50 | S.E. by S. | -2°30 | N.E. by E. | -4°27 | | N.W. | +3°58 | S.W. | +3°8 | S.E. | -3°9 | N.E. | -3°37 | | N.W. by W. | +4°39 | S.W. by S. | +2°24 | S.E. by E. | -3°40 | N.E. by N. | -2°37 | | W.N.W. | +5°8 | S.S.W. | +1°38 | E.S.E. | -4°34 | N.N.E. | -1°40 | | W. by N. | +5°35 | S. by W. | +0°55 | E. by S. | -4°57 | N. by E. | -0°33 | We perceive by this Table that the masses of iron acting on the compass needle of the Terror were distributed, as in the Erebus, symmetrically, or very nearly so, on either side of the vertical plane passing through the longitudinal midship section. Using the formula \[ \cos \zeta \sin \zeta' - b \sin \zeta \cos \zeta' = a \tan \theta \sin \zeta', \] and forming equations for the several points, we have from the sum of those from N. by W. to W. by N., and from N. by E. to E. by N., \[ -4°4516 + 5°3295 b = +23°946 a; \] and for the sum of the equations on the points from S. by W. to W. by S., and from S. by E. to E. by S., \[ -5°5092 + 4°7551 b = -23°946 a, \] whence we derive \( b = +0°9877 \), and \( a = +0°339 \); or including the observations at east and west \( a = 0°343 \). We have next to consider a similar series of observations made in the River Derwent, near Hobarton, in Van Diemen Island, on October 20th, 1840, soon after the first arrival of the Expedition at that station; they were as follows: | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | Ship's head by compass | Attraction towards the west | |------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------|------------------------|----------------------------| | N. | +0°42°4 | W. | -4°36°6 | S. | -0°11°6 | E. | +4°24°4 | | N. by W. | -0°23°6 | W. by S. | -4°44°6 | S. by E. | +0°52°4 | E. by N. | +4°11°4 | | N.N.W. | -1°20°6 | W.S.W. | -4°52°6 | S.S.E. | +1°56°4 | E.N.E. | +4°07°4 | | N.W. by N. | -2°20°6 | S.W. by W. | -5°22°6 | S.E. by S. | +2°38°4 | N.E. by E. | +3°27°4 | | N.W. | -3°25°6 | S.W. | -4°23°6 | S.E. | +3°29°4 | N.E. | +3°02°4 | | N.W. by W. | -3°56°6 | S.W. by S. | -3°31°6 | S.E. by E. | +4°00°4 | N.E. by N. | +2°37°4 | | W.N.W. | -4°01°6 | S.S.W. | -2°03°6 | E.S.E. | +4°43°4 | N.N.E. | +2°11°4 | | W. by N. | -4°06°6 | S. by W. | -1°37°6 | E. by S. | +4°28°4 | N. by E. | +1°26°4 | In the Terror, as in the Erebus, the disturbance had changed its sign in passing from the northern to the southern hemisphere: the symmetrical distribution of the iron on either side of the principal axis of the ship continued as at Gillingham, the observations showing only those very small differences in the exact points of no disturbance, which have been remarked in the Erebus, and which we may be content to view as accidental differences. From these observations, pursuing the usual course, we obtain $b = +9873$, and $a = +0292$. Here also, as in the case of the Erebus, the observations on the first arrival at Hobarton give a somewhat less value for $a \tan \theta$ than those at Gillingham. It is possible that a similar series of experiments may have been repeated in the Terror on the return to the same station in 1841, but no record of it has been received in England, and the observations of 1840 are expressly referred to, in a note appended to them, as furnishing the corrections for the declinations observed between the months of October 1840 and April 1841. I think it not improbable that if the ship were swung in 1841, the resulting value of $a \tan \theta$ will prove, as in the Erebus, to be somewhat greater than in 1840, and that the mean value of $a$ at Hobarton will thereby come into a closer accord with its value at Gillingham. The practical effect of so small a difference is however unimportant, and I have taken $a$ in round numbers for the declinations under consideration $= +030$, and $b = +9875$, and have computed with these values the Tables from which the corrections for the Terror's declinations have been taken. Part of the materials required for the correction of the observations of inclination and intensity, made in the Terror during the voyage under notice, not having yet reached England, the deduction of the constants $c$, $d$, and $A'$ for that ship has been postponed. **Index Correction of Needle R. F. 4 for the Observations of the Inclination in the Erebus.**—The observations of the inclination at sea on board the "Erebus," were made with Mr. Fox's apparatus for determining the magnetic inclination and intensity, and one needle, R. F. 4, was used throughout the observations which are now under consideration. The poles were not reversed; the circle was used with the face east only, and the needle with its marked side towards the observer. An index correction is therefore required for all the sea observations, and must be sought by comparing the inclination shown by the same circle and needle when observed with in the same manner on shore, at stations where the inclination was otherwise determined in an independent and complete manner, viz. by needles of which the poles were reversed, and the needle and circle used in the eight ordinary positions. The determinations of this description made by the Expedition at the Magnetic Observatory at Van Diemen Island in 1840 and 1841, at Auckland Island in November and December 1840, at Campbell's Island in December 1840, and on the ice in lat. $-68^\circ 28'$, long. $176^\circ 32'$, on the 8th of January 1841,—furnishing the required comparison,—were as follows:— Observations of the Inclination, with Needles whose Poles were reversed, made at the Magnetic Observatory in Van Diemen Island in 1840, 1841. | Date | Hour | Needle | Poles. | Mean. | Remarks | |------------|----------|--------|--------|-------|------------------------------| | | | | α direct. | β reversed. | Mean. | Remarks | | 1840. | | | | | | | September 12 | 11 00 A.M. | R G 1 | α -70 32·1 | -70 37·1 | | | | | | β -70 42·1 | | | | | 11 20 A.M. | R G 2 | α -70 35·6 | -70 38·2 | | | | | | β -70 40·9 | | | | | 11 30 A.M. | R 4 | α -70 39·7 | -70 37·6 | | | | | | β -70 35·5 | | | | | 1 30 P.M. | R 10 | α -70 49·8 | -70 51·7 | Needles belonging to H.M.S. Erebus. | | | | | β -70 53·7 | | | | | 11 20 A.M. | R 6 | α -70 46·5 | -70 45·8 | | | | | | β -70 45·2 | | | | | 2 00 P.M. | R 7 | α -70 46·4 | -70 45·8 | | | | | | β -70 45·2 | | | | October 5 | 11 00 A.M. | R 6 | α -70 42·4 | -70 43·2 | | | | | | β -70 44·0 | | | | | 2 00 P.M. | R 7 | α -70 43·3 | -70 42·0 | | | | | | β -70 40·4 | | | | | 2 00 P.M. | D 1 | α -70 31·4 | -70 51·2 | Needles belonging to Sir John Franklin. | | | | | β -71 11·1 | | | | | 11 00 A.M. | D 2 | α -70 08·4 | -70 37·4 | | | | | | β -71 06·4 | | | | | 10 20 A.M. | C 1 | α -70 42·0 | -70 38·3 | Needles belonging to H.M.S. Terror. | | | | | β -70 34·5 | | | | | 11 00 A.M. | C 2 | α -70 34·3 | -70 37·7 | | | | | | β -70 41·2 | | | | 1841. | April 14 | 11 20 A.M. | R 4 | α -70 38·6 | -70 38·7 | | | | | | β -70 38·8 | | | | | | | α -70 46·5 | -70 42·9 | Needles belonging to H.M.S. Erebus. | | | | | β -70 39·3 | | | | | 10 50 A.M. | R 6 | α -70 34·7 | -70 39·0 | | | | | | β -70 43·3 | | | | | 3 30 P.M. | R 7 | α -70 40·6 | -70 37·2 | | | | | | β -70 33·9 | | | | | 1 30 P.M. | R G 1 | α -70 34·4 | -70 36·3 | | | | | | β -70 38·2 | | | | | 11 20 A.M. | R G 2 | α -70 35·7 | -70 37·3 | | | | | | β -70 39·0 | | | | | 11 00 A.M. | C 1 | α -70 41·1 | -70 38·0 | Needles belonging to H.M.S. Terror. | | | | | β -70 35·0 | | | | | Noon. | C 1 | α -70 49·3 | -70 43·1 | | | | | | β -70 37·0 | | | | | 2 00 P.M. | C 2 | α -70 36·9 | -70 34·4 | | | | | | β -70 31·9 | | | | | Noon. | C 1 | α -70 31·2 | -70 36·4 | | | | | | β -70 41·7 | | | | | Noon. | C 2 | α -70 33·0 | -70 39·5 | | | | | | β -70 46·0 | | | | May 10. | 2 20 P.M. | R 4 | α -70 46·6 | -70 42·9 | | | | | | β -70 39·1 | | | | | 4 15 P.M. | R 10 | α -70 53·9 | -70 43·9 | | | | | | β -70 34·0 | | | | | 10 30 A.M. | R 4 | α -70 46·2 | -70 42·4 | | | | | | β -70 38·6 | | | | | 10 45 A.M. | R 4 | α -70 45·4 | -70 40·9 | Needles belonging to H.M.S. Erebus. | | | | | β -70 36·3 | | | | | 2 15 P.M. | R 10 | α -70 47·1 | -70 40·5 | | | | | | β -70 33·1 | | | | June 21. | 9 45 A.M. | R 10 | α -70 45·8 | -70 40·4 | | | | | | β -70 35·1 | | | | | 10 45 A.M. | R 4 | α -70 45·1 | -70 40·8 | General Mean. | | | | | β -70 36·5 | | | General Mean. Observations of the Inclination with Needles whose poles were reversed, made at the Magnetic Observatory at Auckland Island. | Date | Hour | Needle | Poles. | Mean | Remarks | |---------------|------------|--------|--------|----------|--------------------------| | November 23 | 10 20 A.M. | R 4 | $\alpha$ $-73^\circ 17'9"$ | $-73^\circ 13'1"$ | | | | | | $\beta$ $-73^\circ 08'2"$ | | | | 23 | 1 00 P.M. | R 10 | $\alpha$ $-73^\circ 14'4"$ | $-73^\circ 13'4"$ | | | | | | $\beta$ $-73^\circ 12'4"$ | | | | 23 | 2 40 P.M. | R 6 | $\alpha$ $-73^\circ 15'7"$ | $-73^\circ 14'3"$ | | | | | | $\beta$ $-73^\circ 12'9"$ | | | | 23 | 3 30 P.M. | R 7 | $\alpha$ $-73^\circ 14'7"$ | $-73^\circ 13'2"$ | Needles belonging to H.M.S. Erebus. | | | | | $\beta$ $-73^\circ 11'6"$ | | | | 25 | 11 00 A.M. | R G 1 | $\alpha$ $-73^\circ 06'6"$ | $-73^\circ 11'8"$ | | | | | | $\beta$ $-73^\circ 17'0"$ | | | | 25 | 1 00 P.M. | R G 2 | $\alpha$ $-73^\circ 04'0"$ | $-73^\circ 07'8"$ | | | | | | $\beta$ $-73^\circ 11'6"$ | | | | 27 | 3 00 P.M. | C 1 | $\alpha$ $-73^\circ 08'7"$ | $-73^\circ 05'8"$ | H. M. S. Terror. | | | | | $\beta$ $-73^\circ 02'9"$ | | | | 27 | 4 00 P.M. | C 2 | $\alpha$ $-73^\circ 08'2"$ | $-73^\circ 01'8"$ | | | | | | $\beta$ $-72^\circ 55'5"$ | | | | December 4 | 1 40 P.M. | R G 1 | $\alpha$ $-73^\circ 12'2"$ | $-73^\circ 10'4"$ | H. M. S. Erebus. | | | | | $\beta$ $-73^\circ 10'4"$ | | General Mean. | Observations of the Inclination with Needles whose poles were reversed, at Campbell Island. | Date | Hour | Needle | Poles. | Mean | Remarks | |---------------|------------|--------|--------|----------|--------------------------| | December 15 | 9 30 A.M. | C 1 | $\alpha$ $-73^\circ 55'7"$ | $-73^\circ 52'1"$ | Needles belonging to H.M.S. Terror. | | | | | $\beta$ $-73^\circ 48'4"$ | | | | 15 | 10 30 A.M. | C 2 | $\alpha$ $-73^\circ 51'2"$ | $-73^\circ 47'3"$ | | | | | | $\beta$ $-73^\circ 43'4"$ | | | | 15 | 10 30 A.M. | R 4 | $\alpha$ $-73^\circ 56'5"$ | $-73^\circ 50'6"$ | Needles belonging to H.M.S. Erebus. | | | | | $\beta$ $-73^\circ 50'7"$ | | | | 15 | 11 00 A.M. | R 10 | $\alpha$ $-74^\circ 01'5"$ | $-73^\circ 59'4"$ | | | | | | $\beta$ $-73^\circ 57'2"$ | | | | 15 | Noon. | R 6 | $\alpha$ $-73^\circ 45'8"$ | $-73^\circ 47'7"$ | Needles belonging to H.M.S. Erebus. | | | | | $\beta$ $-73^\circ 49'5"$ | | | | 15 | 1 00 P.M. | R 7 | $\alpha$ $-73^\circ 49'5"$ | $-73^\circ 51'4"$ | | | | | | $\beta$ $-73^\circ 53'3"$ | | | | | | | $\beta$ $-73^\circ 51'4"$ | | General Mean. | Inclination observed on Ice, in latitude $-68^\circ 28'$, longitude $176^\circ 32'$, with a Needle the poles of which were reversed. | Date | Hour | Needle | Poles. | Mean | Remarks | |---------------|------------|--------|--------|----------|--------------------------| | January 8 | 3 20 P.M. | R 4 | $\alpha$ $-83^\circ 35'3"$ | $-83^\circ 35'6"$ | H. M. S. Erebus. | | | | | $\beta$ $-83^\circ 35'8"$ | | | The inclinations observed at the four preceding stations with needle R. F. 4, with the face of the circle east, and the marked side of the needle facing the observer, were as follows: Van Diemen Island — \(71^\circ 06'5\); true inclination — \(70^\circ 40'7\); index correction — \(25^\circ 8\) Auckland Island . . — \(73^\circ 41'3\); true inclination — \(73^\circ 10'4\); index correction — \(30^\circ 9\) Campbell Island . . — \(74^\circ 20'3\); true inclination — \(73^\circ 51'4\); index correction — \(28^\circ 9\) On ice, Jan. 8, 1841 — \(84^\circ 02'9\); true inclination — \(83^\circ 36'6\); index correction — \(27^\circ 3\) Mean . . . — \(28^\circ 2\) An index correction of — \(28'\) has therefore been applied in the general table to the mean of the observations on each day with needle R. F. 4, in order to give the true or correct inclination, as it would have been observed by a needle in which the complete process of observation had been gone through. **Elements of Calculation of the Intensity Observations.**—Of the intensity observations made with Mr. Fox’s apparatus on board the Erebus, during the period under consideration, a large proportion was of the angles of deflection produced by deflecting magnets. A spare needle belonging to the apparatus was used as a deflector, and was fitted into a cylindrical case having screws at both ends, so that the needle could be applied either as “deflector N” with its north pole opposite that division of the circle which the north pole of the dipping needle had previously indicated as the dip, —or as “deflector S” with its south pole similarly applied to the opposite division of the circle. The deflectors belonging to the apparatus, being too weak to produce sufficient deflections when used separately, were employed only conjointly, and are designated as “deflectors N and S.” The angles of deflection varied in different localities during the voyage in round numbers as follows: deflector S from \(50^\circ\) to \(45^\circ\); deflector N from \(48^\circ\) to \(43^\circ\); and N and S from \(23^\circ\) to \(20^\circ\). To obtain the equivalent weight to the deflecting force of the deflectors at these angles, we have comparative observations of the angles produced by the deflectors and by weights at Hobarton, Auckland, and Campbell Islands, on the ice on the 8th January in lat. — \(68^\circ 28'\), long. \(176^\circ 32'\), and on five different occasions on board ship when the weather and other circumstances were favourable, viz. on February 8th and 10th, March 22nd, April 1st and 6th. These were exclusive of an attempt on the 1st of February, which failed on account of the ship having too much motion. Hobarton is necessarily the primary station of the whole series of observations made in this portion of the voyage, being the only station at which an independent determination of the intensity has been made. It is also very suitable for a base station, because we may expect that the absolute as well as relative intensity will be determined with great precision at the magnetic observatory established there, and will ultimately furnish a correction, should one be needed, for the provisional value which must for the present be employed. Captain Ross commenced the experiments for measuring the absolute horizontal intensity at Hobarton, by obtaining five results with the large magnets of his observatory magnetometers on different days whilst the Expedition was refitting there. The details of these will be published with the other magnetometric observations of the voyage; the results, which have been computed by Lieutenant Goodenough of the Royal Artillery from the data received from Captain Ross, are as follows: October 13, 1840 . . . . 4·491 May 3, 1841 . . . . . . 4·626 May 21, 1841 . . . . . . 4·602 June 5, 1841 . . . . . . 4·579 June 25, 1841 . . . . . . 4·566 Mean 4·573*. The dip being — 70° 40' at Hobarton, and the approximate value of the absolute horizontal intensity at Woolwich 3·72† with the dip of 69° 03', the corresponding value of the total intensity at Hobarton in the arbitrary scale (London = 1·372) is 1·821. The previous relative observations, collected in No. I. of these Contributions, had given 1·819 as the mean of three determinations, viz. FitzRoy . . . . . . 1836 1·817 Franklin and Sabine . . . . . . 1837 1·810 Wickham . . . . . . 1838 1·830 Mean 1·819. The closeness in the accordance of the mean results by the two methods can only be viewed as accidental, because the probable error of the absolute determination, estimated from the differences in the partial results, is far greater than the difference of the two methods; but it fully warrants 1·82 being now taken as a provisional value of the total intensity at Hobarton, as the base station of the observations which form the subject of this number, regarding 1·82 + e as the true value, and e as a small correction to be determined hereafter, applicable to the whole series. The weights employed in deflecting the intensity needle were from half a grain to six grains. It was soon found that half a grain was too small to give satisfactory results, and observations with that weight were discontinued. I have not therefore taken the observations made with it into account, except at Hobarton, where they * Since these pages were written I have received the results of twenty-two monthly determinations of the absolute horizontal intensity at the magnetic observatory at Hobarton (ten in 1841 and twelve in 1842) made and computed by Lieutenant Kay, R.N., and the naval officers under his direction. The mean in 1841 is 4·553, the partial results varying from 4·601 to 4·509; and the mean in 1842, 4·513, the partial results varying from 4·443 to 4·568. The discordance in the partial results of these observations is scarcely less than in those of Captain Ross: there is also a considerable disagreement in the means of the three series, which may not improbably be diminished when the particulars of the several observations shall have been carefully examined, though the partial results must still be expected to differ much more widely than could be desired. It is hoped that such differences will be reduced within much smaller limits by the use of the improved apparatus which has recently been supplied to the Hobarton as well as to the other colonial observatories. † Philosophical Transactions, 1843, Art. X. assist in computing the angles corresponding to the weights of 4, 5, and 6 grains, which were not commenced with so soon. The observations with the weights on the days above stated, when the weights and deflecting magnets were employed in comparison, are collected in one view and given in the subjoined Table, in which are also shown the angles of deflection produced by the deflecting magnets on the same occasions. | Year | Latitude | Longitude | Weights | Angles of deflection | Thermometer | Intensity deduced | Deflector S | Deflector N | Deflectors N and S | |------|----------|-----------|---------|----------------------|-------------|------------------|------------|------------|-------------------| | 1840 | Hobarton | -42 52 | 147 24 | ½ 2 41·4 52 | 1·820 | 50 01 | Notobserved | Notobserved | | | Auckland Island | -50 33 | 166 19 | 1 5 18·4 52 | 1·844 | 49 29 | 46 50·2 | Notobserved | | | Campbell Island | -52 44 | 169 10 | 1 4 59·2 52 | 1·906 | 49 17 | 46 45·7 | Notobserved | | 1841 | Jan. 8 | -68 28 | 176 32 | 3 14 34·3 42 | 2·024 | 47 16 | 44 17 | 21 55 | | | Feb. 8 | -77 47 | 187 18 | 2 9 15·6 32 | 2·071 | 47 03 | 44 23 | 22 03 | | | Feb. 10 | -77 39 | 187 06 | 3 14 37 34 | 2·019 | 46 55·5 | 44 14 | 21 55·9 | | | Mar. 22 | -63 09 | 139 28 | 3 14 18·6 40 | 2·035 | 46 55 | 44 41 | 22 30 | | | April 1 | -58 13 | 135 18 | 4 19 39·7 58 | 2·037 | 46 55 | 44 41 | 22 30 | | | April 6 | -43 41 | 146 03 | 3 15 59·4 52 | 1·885 | 50 01 | 46 40 | 23 17 | With the angles of deflection at Hobarton produced by the weights ½, 1, 1½, 2 and 3 grains, we obtain the equivalent weight 8·15 grains to the angle \( v = 50° 01' \) of deflector S at the same station; and thence the value of the constant \( \frac{w}{I \sin v} = 5·84 \). in the formula for the equivalent weights to the force of the deflector observed elsewhere, viz. \[ w' = 5.84 I' \sin v'. \] From the values of \( w' \) thus obtained, the subjoined Table has been formed of \( w' \) for each 20' of \( v \) for deflector N and deflector S, in the manner described in No. III. of these Contributions*; and with these values of \( w' \) we have the intensities \( I' \) relative to the force 1.820 at Hobarton computed by means of the formula \[ I' = \frac{I \sin v}{w} \cdot w' \csc v' = 1.71 w' \csc v'. \] | Deflector S. | Deflector N. | |--------------|--------------| | \( v' \) | \( w' \) | \( v' \) | \( w' \) | | 50° 0' | 8.15 | 47° 20' | 7.90 | | 49° 40' | 8.23 | 47° 00' | 7.95 | | 49° 20' | 8.30 | 46° 40' | 8.00 | | 49° 00' | 8.37 | 46° 20' | 8.06 | | 48° 40' | 8.44 | 46° 00' | 8.11 | | 48° 20' | 8.51 | 45° 40' | 8.16 | | 48° 00' | 8.56 | 45° 20' | 8.21 | | 47° 40' | 8.61 | 45° 00' | 8.25 | | 47° 20' | 8.65 | 44° 40' | 8.30 | | 47° 00' | 8.70 | 44° 20' | 8.33 | | 46° 20' | 8.65 | 44° 00' | 8.37 | The results with the original magnets of the apparatus used conjointly, and designated as "N and S," are much inferior in precision to those obtained with the spare intensity needle used as a deflector. The angles of deflection were much less, owing to the force of the magnets, even when used conjointly, being very much inferior to that of the spare needle. The observations are of course given in the Table with the others, but as their results present on the one hand no systematic difference from those with the stronger deflector, and on the other hand are of inferior value, by reason of the extent of their fluctuation,—and as they could only tend therefore to impair the individual accuracy of the results with the stronger deflector and with the weights,—they have been omitted in the means. Comparison of the Intensities deduced by the Weights and by the Deflectors at the Stations at which both were employed. | Station | Latitude | Longitude | Deflector S. | Deflector N. | Weights | |------------------|----------|-----------|--------------|--------------|---------| | Auckland Island | -50° 33' | 166° 19' | 1.862 | 1.873 | 1.852 | | Campbell Island | -52° 41' | 169° 10' | 1.875 | 1.898 | 1.927 | | On ice | -68° 28' | 176° 32' | 2.021 | 2.044 | 2.017 | | At sea | -77° 17' | 187° 18' | 2.034 | 2.038 | 2.053 | | At sea | -77° 39' | 187° 06' | 2.041 | 2.047 | 2.053 | | At sea | -63° 00' | 139° 28' | 2.043 | 2.039 | 2.041 | | At sea | -58° 13' | 135° 18' | 2.042 | 2.017 | 2.037 | | At sea | -43° 41' | 146° 03' | 1.820 | 1.884 | 1.885 | * Philosophical Transactions for 1842, Art. II. General Remarks.—The Tables of the declination observations in the Erebus and Terror, and of the inclination and intensity observations in the Erebus, furnish a full opportunity, for those who may desire it, to examine how far the corrections computed in the manner which has been described fulfil their purpose. The three charts which accompany this number of the "Contributions," exhibit to the eye the determinations contained in the Tables, arranged in their respective localities, by which their general harmony may be, in some measure, judged of. The faint lines, representing the principal curves of the magnetic elements, are drawn in approximate conformity with the observations, and are designed merely to assist the eye in taking a first general view of the results. When the determinations of the succeeding voyages shall have been laid down in a similar manner on a south polar chart, they will furnish the means of judging of the course of the magnetic curves more comprehensively and accurately, and of tracing them accordingly. Rather more attention has been bestowed on the lines in the chart of the inclination than in the other two charts, because it has been used for the values of $\theta$ in the declination-corrections. Having had experience in drawing similar charts on former occasions, and particularly those of the Magnetic Survey of the British Islands, I have no hesitation in recognising with Captain Ross, that as great, and greater, discrepancies are to be looked for, and must frequently be experienced, in magnetic surveys conducted on land, than in those made at sea. The chart of the inclination which accompanies this paper, constructed from observations made at sea, and certainly not under the most favourable circumstances, except in the skill of the observers, exhibits by no means a greater measure of discrepancy than the magnetic chart of Scotland or of Ireland: and it may be further noticed, that the only results which have been excluded altogether from the chart, by reason of their excessive discordance as well with each other as with the general body of results, are some that were made on islands which presented themselves in the course of the voyage. I cannot close this section without calling the attention of all who take interest in the results of these researches, to the invaluable aid for which magnetical science is indebted to Mr. Fox. Without his instrument and method, which render observations of inclination and intensity made at sea nearly or altogether equal to those which could be made on land or on ice, such were the difficulties of the navigation, and such the inaccessible though magnificent character of the coast that was discovered, that two of the three charts herewith presented, and especially that of the intensity, must have offered an appearance very different from that which they now exhibit. To enter into a lengthened comparison of the results now communicated with those of preceding observers, which have been embodied in magnetic maps constructed either directly from the phenomena, or by means of the mathematical theory of M. Gauss, would be to anticipate the more proper opportunity which will present itself, when the whole of the materials collected by the Antarctic Expedition shall be available for the comparison. A few remarks however on prominent points may be looked for on the present occasion. 1. The observations of declination, particularly those which point out the course of the lines of 0 and of 10° east, indicate a more westerly position than the one assigned by M. Gauss in the "Atlas des Erdmagnetismus" for the spot in which all the lines of declination unite. The progression of the lines in the southern hemisphere generally, from secular change, is from east to west; the difference consequently is in the direction in which a change should be found in comparing earlier with more recent determinations. 2. The general form of the curves of higher inclination in the southern hemisphere is much more analogous to that in the northern, than appears in M. Gauss's maps. For example, the isoclinal line of — 85° instead of being nearly circular, as represented in the 3te Abtheilung of Pl. XVI. of the "Atlas des Erdmagnetismus," is an elongated ellipse, much more nearly resembling in form and dimensions the ellipse of 85° of inclination in the northern hemisphere in the same work, Pl. XVI. 2te Abtheilung. The analogy between the two hemispheres in the characteristic feature of the elliptical form of the higher isoclinal lines is the more important to notice, on account of the particular relation which appears to subsist in the northern hemisphere, between the change in the geographical direction of the greater axis of the ellipse, and the secular changes of the inclination generally throughout the hemisphere. The present direction of the greater axis in the northern hemisphere is nearly N.N.W. and S.S.E., or that of a line passing through the two foci of maximum intensity. In the southern hemisphere the present direction of the greater axis differs little from E.S.E. and W.N.W. 3. Captain Ross's observations of the intensity do not appear to indicate the existence anywhere in the southern hemisphere of a higher intensity than would be expressed by 2·1 of the arbitrary scale. In this respect also the analogy between the two hemispheres appears to be closer than is shown in M. Gauss's maps, Atlas, Pl. XVIII. With respect to the direction of so much of the line of highest intensity (2·0) as it has been possible to draw with any degree of confidence from the observations now communicated, it will be found to be in almost exact parallelism with the isodynamic line of 1·7 in Plate III. of my memoir "On the Variations of the Magnetic Intensity" in the Reports of the British Association for 1838; which line was the highest of which the position could be assigned, for any considerable distance, by the aid of the then existing determinations. Observations of the MAGNETIC DECLINATION made in the Expedition commanded by CAPT. JAMES CLARK ROSS R.N. between November 1840 and April 1841. The observations of the Erebus are in Roman; thus -96.30 The observations of the Terror are in Italic: thus -88.10 Observations of the INTENSITY OF THE MAGNETIC FORCE, made in the expedition commanded by CAPT. JAMES CLARK ROSS R.N. between July 1840, and April 1841. made in the expedition commanded by CAPT. JAMES CLARK ROSS R.N. between July 1840, and April 1841. Observations of the MAGNETIC INCLINATION made in the Expedition commanded by CAPT. JAMES CLARK ROSS R.N. between July 1840, and April 1841. § 9. Observations of the Magnetic Inclination and Intensity made on board Her Majesty's ship Erebus on the passage from Kerguelen Island to Van Diemen Island in July and August 1840. These observations were made with Mr. Fox's apparatus, and with the same needle F which had been employed in the determinations made at sea on the passage from England to Kerguelen Island, discussed in § 5 and § 6 of these Contributions*. The inclinations at sea were observed with the face of the circle always to the east: the index correction for needle F in this position of the instrument has been derived by comparing similar observations made with it at the magnetic observatory at Kerguelen Island, with the results obtained at the same spot with other needles which had their poles reversed. These are contained in the following Table: Observations of the Inclination with needles whose poles were reversed, made at the Magnetic Observatory at Kerguelen Island, July 1840. | 1840 | Hours | Needle | Poles. | Mean | Remarks | |------|-------|--------|-------|------|---------| | | | | α direct. | β reversed. | | | July 4 | 10 A.M. | C 1 | α - 69° 59' 7" | β - 69° 58' 4" | -69° 59' 0" | | | 6 P.M. | C 2 | α - 69° 59' 0" | β - 69° 50' 2" | -69° 54' 6" | | | 6 15 P.M. | C 1 | α - 69° 59' 8" | β - 70° 01' 6" | -70° 00' 7" | | | 6 30 P.M. | C 2 | α - 69° 59' 7" | β - 69° 48' 7" | -69° 54' 2" | | | 7 20 P.M. | C 2 | α - 69° 47' 8" | β - 70° 01' 0" | -69° 54' 4" | | | 1 45 P.M. | R 4 | α - 70° 03' 1" | β - 70° 02' 0" | -70° 02' 5" | | | 5 30 P.M. | R G 1 | α - 69° 54' 3" | β - 70° 03' 8" | -69° 59' 1" | | | 7 30 P.M. | R G 2 | α - 69° 57' 7" | β - 70° 04' 0" | -70° 00' 8" | | | 9 A.M. | R 10 | α - 70° 13' 9" | β - 70° 08' 9" | -70° 11' 4" | -69° 59' 6" General Mean. The inclination observed with needle F at the same spot with the face of the circle towards the east was — 69° 57' 9"; whence the index correction is — 1' 7". The intensity of the magnetic force was determined in this portion of the voyage, on every day that the weather permitted, by the angles of deflection caused by a deflecting magnet. The observations were a continuation of the series of which the earlier portion is given in § 5 and § 6. The deflecting magnet employed was the deflector S. Tables are given, in the sections referred to, of the values of \( w' \) for this deflector corresponding to angles of deflection from 42° to 25°, derived from a comparison with the deflections produced by weights. The increase of the terrestrial force, in the passage between Kerguelen and Van Diemen Islands, brought the angle * Philosophical Transactions, 1842, Art. II. of deflection with deflector S down nearly to $20^\circ$. The weather was too unsettled to admit of any comparison being made with the weights at sea, and an accident which befell the needle on or before the arrival at Hobarton prevented the comparison which otherwise would have been made there. The values of $w'$ corresponding to the angles of deflection from $25^\circ$ to $20^\circ$ have, therefore, been supplied, by continuing the rate of progression at which the deflecting force of the magnet S had been found by experiment, in angles from $36^\circ$ to $25^\circ$, to increase as the angle diminished, viz. $0.033$ gr. for each degree; we have thus the following values: \[ \begin{align*} v' &= 26^\circ & w' &= 2.594 \\ v' &= 25^\circ & w' &= 2.628 \\ v' &= 24^\circ & w' &= 2.661 \\ v' &= 23^\circ & w' &= 2.694 \\ v' &= 22^\circ & w' &= 2.727 \\ v' &= 21^\circ & w' &= 2.760 \\ v' &= 20^\circ & w' &= 2.793. \end{align*} \] At Kerguelen Island we have the angle of deflection with the magnet $S = 26^\circ 21'3 = v$; the equivalent weight $= 2.58 = w$; and (§ 6.) $I = 1.465$ (London $= 1.372$); whence in other localities \[ I' = I \frac{w' \sin v}{w \sin v'} = 2.521 w' \csc v', \] $v'$ being furnished by the observation and $w'$ taken from the preceding Table. The last observation recorded to have been made with needle F was on the 11th of August, 1840, in lat. $-44^\circ 16'$, long. $142^\circ 38'$; when the angle of deflection being $21^\circ 06'5$, $I' = 1.929$ uncorrected for the ship's attraction, or (the course being E. by N. $\frac{1}{2}$ N.), $I' = 1.934$ corrected. On the return of the Expedition from the Antarctic Circle in the following year, the ships regained their former track, and on the 5th of April, 1841, Captain Ross repeated the observations with different instruments within a few miles of the spot on which he had observed on the 11th of August, 1840: these observations gave $I' = 1.927$ in lat. $-45^\circ 02'$, long. $143^\circ 10'$. If we examine the map in which the intensity observations are inserted, we perceive that the direction of the two geographical positions in relation to each other is very nearly that of the isodynamic lines in that quarter; and if we refer generally to the Tables, we see that the difference in the resulting intensity on the two occasions is within the limits of the differences of partial determinations with the same instrument at one spot. As far as circumstances permit us to judge, therefore, we may view the observations of the two voyages as forming parts of one connected series. As the ship's head during the run under consideration varied but little on any occasion from her direct course, and as that course is one on which the corrections, both of inclination and intensity, are small, I have taken them from the Table computed by means of the constants deduced in the preceding section. Observations of the Inclination with Needle F on board H.M.S. Erebus, between July 22nd and August 11, 1840, on her passage from Christmas Harbour, Kerguelen Island, to Hobarton, Van Diemen Island. | 1840 | Latitude | Longitude | Method employed | Inclination Face east | Ship's head | Corrections for ship's attraction | Corrected inclination | Remarks | |------|----------|-----------|-----------------|-----------------------|-------------|----------------------------------|----------------------|---------| | June 26 | Magnetic Observatory, Kerguelen Island. | Direct. | -70° 02' 8" | S. and N. | Observed on shore. | -69° 59' 6" | Remark by Captain Ross. "From these observations the Index error of Needle F.(face east), as used on board ship, may be obtained." | | July 22 | -48° 29' | 76° 55' | Direct. | -70° 34' 5" | S.E. by E. | -18° | -70° 55' | Considerable swell. | | 23. | -48° 17' | 80° 15' | Direct. | -71° 48' | S.E. by E. | -12° | -71° 50' | A high sea. | | 24. | -47° 55' | 83° 51' | Direct. | -72° 10' | S.E. by E. | -13° | -72° 34' | Too much motion to continue. | | 25. | -47° 46' | 86° 18' | Direct. | -73° 4' 5" | S.E. by E. | -15° | -73° 33' | | | 26. | -47° 12' | 89° 45' | Direct. | -73° 13' | S.E. by E. | -15° | -73° 35' | | | 27. | -47° 03' | 93° 0' | Direct. | -74° 11' 3" | S.E. by E. | -16° | -74° 37' | | | 28. | -47° 13' | 97° 07' | Direct. | -74° 27' 5" | S.E. by E. | -8° | -74° 28' | | | 29. | -47° 39' | 102° 42' | Direct. | -74° 15' | E.S.E. | -8° | -74° 31' | | | 30. | -47° 35' | 106° 26' | Direct. | -74° 15' 2" | E.S.E. | -9° | -75° 08' | Much motion. | | Aug. 1 | -47° 45' | 110° 39' | Direct. | -74° 48' | E.S.E. | -1° | -75° 26' | | | 2. | -47° 34' | 114° 15' | Direct. | -75° 20' 5" | E.by s. | +6° | -76° 04' | Much motion. | | 3. | -47° 41' | 121° 30' | Direct. | -76° 9' 8" | E.by s. | +13° | -76° 40' | Very unsteady. | | 4. | -47° 34' | 124° 43' | Direct. | -76° 49' 2" | E. ½ s. | +21° | -75° 41' | | | 5. | -46° 44' | 128° 26' | Direct. | -76° 53' 7" | E. | +29° | -75° 17' | | | 6. | -46° 13' | 132° 0' | Direct. | -75° 43' 7" | E. ½ N. | +36° | -73° 48' | | | 7. | -45° 59' | 135° 38' | Direct. | -74° 33' 5" | E.by N. | +48° | -73° 23' | | | 8. | -45° 17' | 139° 19' | Direct. | -74° 17' 5" | E.N.E. | +59° | -72° 37' | | | 9. | -44° 24' | 141° 39' | Direct. | -73° 39' 15" | N.E.by E. | +42° | -73° 03' | | The index correction — 1'7 has been applied in the final column. | Latitude | Longitude | Method employed | Angle of deflection | Temperature | Ship's head | Corrections for ship's attraction | Corrected intensity London = 1°37'2" | Remarks | |----------|-----------|-----------------|---------------------|-------------|------------|----------------------------------|-----------------------------------|---------| | June 26 | On shore at Kerguelen Island. | W. 1½ gr. | 14° 48' 6" | 34° 5' | Observed on shore. | 1° 465 | 1° 465 | At the Magnetic Observatory. | | | and 28° S. | W. 2 grs. | 20° 19' 6" | 34° 5' | s.e. by E. | 1° 563 | 1° 539 | | | July 22 | —48° 41' | 68° 54' | S. | 26° 21' 3" | s.e. by E. | 1° 594 | 1° 574 | | | | —48° 29' | 76° 55' | S. | 25° 0' 3" | s.e. by E. | 1° 621 | 1° 601 | | | | —48° 17' | 80° 15' | S. | 24° 39' 4" | s.e. by E. | 1° 595 | 1° 575 | Considerable swell. | | | —47° 55' | 83° 51' | S. | 24° 20' | s.e. by E. | 1° 585 | 1° 565 | | | | —47° 46' | 86° 18' | S. | 24° 38' 5" | s.e. by E. | 1° 582 | 1° 562 | | | | —47° 12' | 89° 45' | S. | 24° 46' 5" | s.e. by E. | 1° 579 | 1° 559 | | | | —47° 03' | 93° 0' | S. | 23° 04' | s.e. by E. | 1° 576 | 1° 556 | | | | —47° 13' | 97° 07' | S. | 23° 04' | s.e. by E. | 1° 573 | 1° 553 | | | | —47° 39' | 102° 42' | S. | 21° 37' 5" | s.e. by E. | 1° 570 | 1° 550 | | | | —47° 35' | 106° 26' | S. | 21° 33' 6" | s.e. by E. | 1° 567 | 1° 547 | | | | —47° 45' | 110° 39' | S. | 22° 01' 7" | s.e. by E. | 1° 564 | 1° 544 | | | Aug. 1 | —47° 34' | 114° 15' | S. | 20° 37' | s.e. by E. | 1° 561 | 1° 541 | | | | —47° 41' | 121° 30' | S. | 20° 27' 7" | s.e. by E. | 1° 558 | 1° 548 | | | | —47° 34' | 124° 43' | S. | 20° 28' 2" | s.e. by E. | 1° 555 | 1° 545 | | | | —46° 44' | 128° 26' | S. | 20° 10' 5" | s.e. by E. | 1° 552 | 1° 542 | | | | —46° 13' | 132° 0' | S. | 20° 39' 2" | s.e. by E. | 1° 549 | 1° 539 | | | | —45° 59' | 135° 38' | S. | 20° 34' 7" | s.e. by E. | 1° 546 | 1° 536 | | | | —45° 17' | 139° 19' | S. | 20° 31' 1" | s.e. by E. | 1° 543 | 1° 533 | | | | —44° 24' | 141° 39' | S. | 20° 48' 7" | s.e. by E. | 1° 540 | 1° 530 | | | | —44° 16' | 142° 38' | S. | 21° 06' 5" | s.e. by E. | 1° 537 | 1° 527 | | Observations of the Magnetic Intensity with Needle F, on board H.M.S. Erebus, between July 22nd and August 11th, 1840, in her passage from Christmas Harbour, Kerguelen Island, to Hobarton, Van Diemen Island. **DECLINATIONS observed on board Her Majesty's Ship Erebus between November 15, 1840, and April 6, 1841.** The Observers are distinguished in the column of Initials as follows:—R. Captain Ross; S. Lieut. Sibbald; W. Lieut. Wood; T. Mr. Tucker, Master; Sm. Mr. Smith, and O. Mr. Oakley, Mates; Y. Mr. Yule, Second Master. East Declination is characterised by the sign —. | 1840 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|---------------------|----------------|---------| | Nov. 15 P.M. | Lat. Long. | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | | -45°33' | 152°49' | R. | -8°55' | E.S.E. | -71°40' | -4°39' | -13°34' | -13°09' | | | -45°33' | 152°49' | T. | -8°37' | E.S.E. | -4°39' | -13°16' | -13°09' | | | -45°33' | 152°49' | R. | -8°23' | E.S.E. | -4°39' | -13°02' | -13°09' | | | -45°33' | 152°49' | T. | -8°25' | E.S.E. | -4°39' | -13°04' | -13°09' | | | -45°38' | 152°55' | Sm. | -8°10' | E.S.E. | -4°39' | -12°49' | -13°09' | | | -45°38' | 152°55' | R. | -8°32' | E.S.E. | -4°39' | -13°11' | -13°09' | | | -45°38' | 152°55' | R. | -8°22' | E.S.E. | -4°39' | -13°01' | -13°09' | | | -45°40' | 153°02' | R. | -8°40' | E.S.E. | -4°39' | -13°19' | -13°09' | | | 16 A.M. | -46°05' | 154°11' | T. | -8°31' | S.E.by E.½ E. | -72°04' | -4°34' | -13°51' | -13°38' | | -46°05' | 154°11' | Y. | -8°39' | S.E.by E.½ E. | -4°34' | -13°57' | -13°38' | | | -46°05' | 154°11' | S. | -8°56' | S.E.by E. | -4°34' | -13°13' | -13°38' | | | -46°09' | 154°14' | S. | -9°17' | S.E.by E.½ E. | -4°34' | -13°19' | -13°38' | | | -46°09' | 154°14' | Y. | -9°23' | S.E.by E.½ E. | -4°34' | -13°57' | -13°38' | | | -46°09' | 154°14' | T. | -9°40' | S.E.by E.½ E. | -4°34' | -14°14' | -13°38' | | | -46°09' | 154°14' | T. | -8°31' | S.E.by E.½ E. | -4°34' | -13°05' | -13°38' | | | -46°15' | 154°28' | S. | -9°50' | S.E.by E.½ E. | -4°34' | -14°24' | -13°38' | | | 16 P.M. | -46°30' | 154°54' | T. | -13°29' | N. | 0°00' | -13°29' | -13°58' | | -46°30' | 154°54' | S. | -14°55' | N.by E. | -0°46' | -15°41' | -13°58' | | -46°30' | 154°54' | T. | -12°57' | N.N.E. | -1°30' | -14°27' | -13°58' | | -46°30' | 154°54' | T. | -8°05' | S.E.by E.½ E. | -4°34' | -12°39' | -13°58' | | | -46°30' | 154°54' | R. | -9°12' | S.E.by E.½ E. | -4°34' | -13°46' | -13°58' | | | -46°30' | 154°54' | R. | -9°15' | S.E.by E.½ E. | -4°34' | -13°49' | -13°58' | | | -46°32' | 155°01' | T. | -9°19' | S.E.by E.½ E. | -4°34' | -13°53' | -13°58' | | | 18 P.M. | -49°36' | 160°52' | R. | -13°11' | E.S.E. | -74°00' | -5°19' | -17°16' | -17°16' | | -49°42' | 160°56' | R. | -12°27' | E.S.E. | -4°34' | -18°24' | -17°16' | | -49°48' | 161°00' | R. | -11°49' | E.S.E. | -4°34' | -18°21' | -17°16' | | -49°49' | 161°00' | T. | -12°18' | E.S.E. | -4°34' | -18°24' | -17°16' | | -49°49' | 161°00' | T. | -12°03' | E.S.E. | -4°34' | -18°21' | -17°16' | | -49°52' | 161°08' | R. | -11°18' | E.S.E. | -4°34' | -18°24' | -17°16' | | -49°52' | 161°08' | S. | -10°27' | E.S.E. | -4°34' | -18°21' | -17°16' | | Dec. 5 A.M. | -50°32' | 166°12' | ... | -22°29' | S.W. | +4°05' | -18°24' | -17°44' | | At anchor. | ... | ... | ... | -22°26' | S.W. | +4°05' | -18°21' | -17°44' | | P.M. Auckland Island. | R. | -17°49' | Observed on shore. | -17°44' | | -50°32' | 166°12' | -17°44' | | -17°44' | | At anchor. | -17°45' | | | -17°44' | | At anchor. | -17°42' | | | -17°44' | | At anchor. | -17°42' | | | -17°44' | | 8 P.M. | -16°44' | S. | 0°00' | -16°44' | | At anchor. | -16°20' | S.S.W. | +2°17' | -14°03' | | At anchor. | -20°26' | N.N.W. | +1°39' | -18°47' | | At anchor. | -22°35' | N.W. | +3°10' | -19°25' | | At anchor. | -20°17' | N.N.W. | +1°39' | -18°38' | | At anchor. | -19°56' | N.N.W.½ W. | +2°03' | -17°53' | | At anchor. | -19°54' | N.N.W. | +1°39' | -18°15' | | At anchor. | -15°38' | N.N.E. | -1°39' | -17°17' | | At anchor. | -15°46' | N.E. | -3°10' | -18°56' | | At anchor. | -13°36' | E.N.E. | -4°23' | -17°59' | | At anchor. | -12°52' | E. | -5°05' | -17°57' | -17°53' | ## Observations of Declination. (Continued.) | Year | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|----------------------|-----------------|---------| | 1840 | Auckland Island | T. | -22° 06' | W.N.W. | -73° 15' | + 4° 23' | -17° 43' | -17° 53' | At anchor. | | | | T. | -21° 39' | N.W. by W. | + 3° 50' | -17° 49' | | | | | | | T. | -22° 49' | W. | + 5° 05' | -17° 44' | | | | | | | T. | -23° 19' | W. by N. | + 4° 50' | -18° 29' | | | | | | | T. | -23° 01' | W. | + 5° 05' | -17° 56' | | | | | | | T. | -22° 26' | W. by N. | + 4° 50' | -17° 36' | | | | | | | T. | -21° 32' | N.W. by N. | + 2° 48' | -18° 44' | | | | | | | R. | -12° 33' | S.E. by E. | -4° 46' | -17° 19' | | | | | | | S. | -12° 15' | S.E. by E. | -4° 58' | -17° 13' | | | | | | | T. | -12° 30' | S.E. by E. | -4° 46' | -17° 16' | | | | | | | T. | -10° 15' | S.E. by E. | -4° 46' | -15° 01' | | | | | | | S. | -11° 06' | S.E. by E. | -4° 46' | -15° 52' | | | | | | | Y. | -9° 46' | S.E. by E. | -4° 46' | -14° 32' | | | | | | | S. | -10° 37' | S.E. by E. | -4° 28' | -15° 05' | | | | | | | R. | -22° 19' | S.W. by W. | + 4° 32' | -17° 47' | | | | | | Campbell Island | R. | -23° 14' | W.S.W. | + 5° 17' | -17° 57' | | | | | | | R. | -15° 53' | S.S.E. | -2° 29' | -18° 22' | | | | | | | S. | -15° 41' | S.S.E. | -2° 29' | -18° 10' | | | | | | | R. | -15° 21' | S.S.E. | -3° 00' | -18° 21' | | | | | | | T. | -17° 31' | S.S.E. | -2° 29' | -20° 00' | | | | | | | S. | -15° 42' | S.S.E. | -2° 29' | -18° 11' | | | | | | | S. | -18° 47' | S. ½ W. | -3° 01' | -23° 41' | | | | | | | S.M. | -20° 40' | S.S.E. | -3° 01' | -22° 40' | | | | | | | T. | -19° 39' | S.S.E. | -3° 01' | -23° 44' | | | | | | | Y. | -20° 43' | S.S.E. | -3° 01' | -21° 19' | | | | | | | T. | -18° 18' | S.S.E. | -3° 01' | -23° 44' | | | | | | | S.M. | -20° 43' | S.S.E. | -3° 01' | -20° 10' | | | | | | | S. | -17° 09' | S.S.E. | -0° 44' | -19° 50' | | | | | | | O. | -19° 06' | S. ½ E. | -2° 15' | -22° 15' | | | | | | | T. | -20° 00' | S.by E. ½ E. | 0° 00' | -21° 54' | | | | | | | R. | -21° 54' | S. | -3° 01' | -20° 44' | | | | | | | S. | -17° 43' | S.S.E. | -3° 01' | -25° 38' | | | | | | | R. | -24° 54' | S. ½ E. | -0° 44' | -25° 38' | | | | | | | S. | -23° 29' | S.by W. ½ W. | + 2° 15' | -21° 14' | | | | | | | O. | -24° 32' | S.by W. ½ W. | + 2° 15' | -22° 17' | | | | | | | T. | -19° 34' | S.S.E. | -3° 12' | -22° 46' | | | | | | | T. | -19° 08' | S.E.by S. | -4° 29' | -23° 37' | | | | | | | T. | -23° 25' | S.by W. ½ W. | + 2° 30' | -20° 55' | | | | | | | Y. | -21° 54' | S. ¼ W. | + 1° 15' | -20° 39' | | | | | | | Y. | -21° 12' | S.by W. | + 1° 40' | -19° 32' | | | | | | | R. | -17° 57' | S.E.by S. | -4° 39' | -22° 36' | | | | | | | T. | -17° 19' | S.S.E. | -3° 18' | -20° 37' | | | | | | | T. | -15° 01' | S.E. ¼ E. | -6° 03' | -21° 04' | | | | | | | S.M. | -20° 07' | S.S.E. | -3° 21' | -23° 28' | | | | | | | T. | -20° 17' | S.by E. | -1° 43' | -22° 00' | | | | | | | S. | -18° 03' | S. ½ W. | 0° 00' | -21° 33' | | | | | | | S. | -18° 03' | S.by E. ½ E. | + 0° 25' | -21° 13' | | | | | | | O. | -20° 21' | S.S.E. | -6° 03' | -26° 04' | | | | | | | T. | -21° 27' | S.by E. | -2° 30' | -20° 33' | | | | | | | Y. | -20° 01' | S.E. | -3° 21' | -23° 42' | | | | | | | S. | -18° 03' | S.by E. ½ E. | -1° 43' | -23° 10' | | | | | | | O. | -20° 21' | S.S.E. | -3° 21' | -23° 34' | | | | | | | R. | -20° 13' | S.S.E. | -3° 21' | -22° 52' | | | | ## Observations of Declination. (Continued.) | Year | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|-------------|---------------------------------|----------------------|----------------|---------| | **1840** | | | | | | | | | | | Dec. 24 P.M. | -60° 42' | 170° 55' | R. | -16° 49' | S.E. | -6° 06' | -22° 55' | | | | | -60° 42' | 170° 55' | R. | -18° 03' | S.E. by s. | -4° 52' | -22° 55' | | | | | -60° 46' | 170° 55' | R. | -18° 06' | S.E. by s. | -4° 52' | -22° 58' | | | | | -60° 46' | 170° 55' | R. | -18° 23' | S.E. by s. | -4° 52' | -23° 15' | | | | | -60° 46' | 170° 55' | S. | -19° 37' | S. by E. ½ E. | -2° 40' | -22° 17' | | | | | -60° 46' | 170° 55' | T. | -18° 42' | S.S.E. | -3° 25' | -22° 07' | | | | | -60° 48' | 170° 55' | R. | -18° 02' | S.E. by s. | -4° 52' | -22° 54' | | | | | -60° 48' | 170° 55' | T. | -17° 35' | S.E. by s. | -4° 52' | -22° 27' | | | | | -60° 48' | 170° 40' | S. | -17° 33' | S.E. by s. | -4° 52' | -22° 25' | | | | | -60° 50' | 170° 44' | R. | -17° 57' | S.E. by s. | -4° 52' | -22° 49' | | | | | -60° 55' | 170° 41' | S. | -16° 46' | S.S.E. ½ E. | -4° 07' | -20° 53' | | | | | -64° 10' | 172° 28' | R. | -30° 28' | S.S.W. | +4° 06' | -26° 22' | | | | | -64° 10' | 172° 28' | R. | -29° 24' | S.S.W. | +4° 06' | -25° 18' | | | | | -64° 10' | 172° 28' | R. | -27° 34' | S.by w. | +2° 06' | -25° 28' | | | | | -64° 12' | 172° 29' | Sm. | -25° 30' | S. ½ W. | +1° 02' | -24° 28' | | | | | -64° 12' | 172° 29' | S. | -25° 32' | S. ½ W. | +1° 02' | -24° 30' | | | | | -64° 12' | 172° 29' | S. | -23° 32' | S.E. | -7° 24' | -30° 56' | | | | | -64° 27' | 172° 36' | S. | -30° 04' | S.W. ½ S. | +6° 44' | -23° 20' | | | | | -64° 27' | 172° 36' | S. | -31° 18' | S.W. ½ S. | +6° 44' | -24° 34' | | | | | -64° 27' | 172° 36' | T. | -32° 36' | S.W. | +7° 30' | -25° 06' | | | | | -64° 37' | 172° 40' | Y. | -31° 01' | S.W. ½ W. | +8° 04' | -22° 57' | | | | | -64° 37' | 172° 40' | Sm. | -31° 54' | S.S.W. | +4° 11' | -27° 43' | | | | | -64° 37' | 172° 40' | R. | -23° 26' | S. | 0° 00' | -23° 26' | | | | | -64° 37' | 172° 40' | T. | -24° 08' | S. | 0° 00' | -24° 08' | | | | | -64° 37' | 172° 40' | S. | -26° 01' | S. | 0° 00' | -26° 01' | | | | | -64° 44' | 172° 50' | R. | -25° 03' | S.S.E. | -4° 11' | -29° 14' | | | | | -64° 46' | 172° 50' | R. | -23° 04' | S.S.E. | -4° 11' | -27° 15' | | | | | -64° 48' | 172° 50' | R. | -22° 43' | S.S.E. | -4° 11' | -26° 54' | | | | | -65° 22' | 172° 25' | S. | -22° 13' | S.S.E. | -4° 25' | -26° 38' | | | | | -65° 22' | 172° 25' | O. | -19° 39' | S.S.E. ½ E. | -5° 24' | -25° 03' | | | | | -65° 23' | 172° 21' | S. | -22° 06' | S.by E. ½ E.| -3° 20' | -25° 26' | | | | | -65° 25' | 172° 21' | O. | -21° 33' | S.by E. | -2° 15' | -23° 48' | | | | | -65° 25' | 172° 21' | S. | -22° 15' | S.by E. | -2° 15' | -24° 30' | | | | | -65° 30' | 172° 16' | T. | -22° 36' | S.by E. | -2° 15' | -24° 51' | | | | | -65° 30' | 172° 16' | T. | -23° 00' | S. ½ E. | -1° 05' | -24° 05' | | | | | -65° 31' | 172° 16' | Y. | -27° 33' | S. ½ W. | +1° 05' | -26° 28' | | | | | -65° 31' | 172° 16' | S. | -22° 33' | S. | 0° 00' | -22° 33' | | | | | -65° 32' | 172° 14' | T. | -24° 02' | S. | 0° 00' | -24° 02' | | | | | -66° 04' | 171° 34' | T. | -29° 03' | S. | 0° 00' | -29° 03' | | | | | -66° 07' | 171° 34' | Sm. | -29° 23' | S. ½ W. | +1° 13' | -28° 10' | | | | | -66° 07' | 171° 34' | S. | -30° 05' | S. ½ W. | +1° 13' | -28° 52' | | | | | -66° 07' | 171° 34' | T. | -30° 38' | S. ½ W. | +1° 13' | -29° 25' | | | | | -66° 09' | 171° 32' | R. | -30° 39' | S.by w. | +2° 30' | -28° 09' | | | | **1841** | | | | | | | | | | | Jan. 1 A.M. | -66° 09' | 171° 32' | W. | -35° 45' | N.W. by w. | +9° 18' | -26° 27' | | | | | -66° 20' | 170° 32' | S. | -32° 20' | S.S.W. | +4° 50' | -27° 30' | | | | | -66° 28' | 170° 48' | R. | -32° 44' | S.S.W. | +4° 50' | -27° 54' | | | | 1 P.M. | -66° 20' | 169° 13' | T. | -20° 18' | S.E. | -8° 47' | -29° 05' | | | | 2 A.M. | -66° 20' | 169° 13' | T. | -17° 35' | E.S.E. | -11° 11' | -28° 46' | | | | | -66° 20' | 169° 13' | T. | -17° 44' | S.E.by E. | -8° 47' | -31° 08' | | | | | -66° 20' | 169° 13' | Y. | -17° 53' | S.E.by E. | -10° 11' | -28° 55' | | | | | -66° 20' | 169° 41' | S. | -17° 08' | S.E.by E. | -10° 11' | -28° 04' | | | | | -66° 20' | 169° 41' | T. | -17° 01' | E.S.E. | -10° 11' | -27° 19' | | | | | -66° 20' | 169° 43' | R. | -16° 33' | E.S.E. | -11° 11' | -28° 12' | | | | | -66° 24' | 169° 44' | R. | -17° 52' | E.S.E. | -11° 11' | -29° 03' | | | MDCCCXLIII. ## Observations of Declination. (Continued.) | Year | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|---------------------|----------------|---------| | 1841 | Jan. 2 A.M. | -66°30'169°44' T. | -35°14' W.N.W. ½ W. | -82°30' +10°55' -24°19' | -27°21' | | | | -66°30'169°44' W. | -35°45' N.W. by W. | +9°18' -26°27' | | | | -66°30'169°46' R. | -35°31' N.W. by W. | +9°18' -26°13' | | | | -66°30'169°46' S. | -34°28' N.N.W. ½ W. | +5°11' -29°17' | | | | -66°29'169°48' O. | -31°46' N.W.W. | +4°11' -27°35' | | | 4 A.M. | -65°28'171°47' S. | -20°09' S.E. by S. | -6°35' -26°44' | | | | -65°28'171°47' O. | -18°33' S.E. | -8°15' -26°48' | | | | -65°28'171°47' W. | -19°43' S.E. by E. | -9°33' -29°16' | | | | -65°28'171°47' T. | -17°46' E. by S. ¾ S. | -10°38' -28°24' | | | | -65°28'171°47' T. | -17°28' E. by S. ¾ S. | -10°38' -28°06' | | | | -65°28'171°56' W. | -16°43' E. by S. ½ S. | -10°45' -27°28' | | | 4 P.M. | -65°26'172°50' R. | -15°21' S. 79° E. | -11°00' -26°21' | | | | -65°26'172°50' R. | -15°44' S. 74° E. | -10°45' -26°29' | | | | -65°26'173°06' T. | -16°14' E. by S. | -11°00' -27°14' | | | | -65°26'173°06' T. | -17°00' E.S.E. | -10°30' -27°30' | | | | -65°27'173°32' R. | -18°22' S. 67° E. | -10°30' -28°52' | | | | -65°27'173°32' W. | -14°08' E.S.E. | -10°12' -24°20' | | | | -65°27'173°32' R. | -17°26' S. 72° E. | -10°17' -27°43' | | | | -65°27'173°32' R. | -18°59' S. 63° E. | -9°45' -28°44' | | | | -65°27'173°32' S.M. | -18°35' E.S.E. | -10°12' -28°47' | | | | -65°27'173°32' T. | -17°55' S.E.S.E. | -10°12' -28°07' | | | | -65°29'173°55' R. | -18°08' S. 68° E. | -10°12' -28°20' | | | | -65°30'173°55' R. | -19°42' S.E.by E. ½ E. | -9°45' -29°27' | | | | -65°40'173°55' Y. | -19°16' S.E. ½ E. | -8°38' -27°54' | | | | -65°32'173°55' T. | -23°49' S.by E. ½ E. | -3°21' -27°10' | | | | -65°34'173°55' R. | -22°48' S.E. | -7°56' -30°44' | | | 5 A.M. | -65°39'174°14' Y. | -29°46' S.E.by S. | -7°04' -36°50' | | | | -66°39'174°14' S.M. | -21°41' S.E. | -8°47' -30°28' | | | 5 P.M. | -67°12'174°41' R. | -28°05' S.S.E. | -5°11' -33°16' | | | | -67°12'174°42' T. | -29°49' S.by E. | -2°42' -32°31' | | | | -67°12'174°42' Y. | -30°10' S. ¾ E. | -2°01' -32°11' | | | | -67°12'174°42' Y. | -27°59' S.S.E. ½ E. | -6°25' -34°24' | | | | -67°23'174°42' R. | -18°03' E.S.E. | -11°57' -30°00' | | | | -67°23'174°42' T. | -17°25' E.S.E. | -11°57' -29°22' | | | | -67°23'174°42' T. | -18°05' S.E.by E. | -10°53' -28°58' | | | | -67°23'174°42' T. | -17°13' E.S.E. | -11°57' -29°10' | | | | -67°23'174°42' R. | -18°07' E.S.E. | -11°57' -30°04' | | | | -67°27'174°42' R. | -18°44' E.S.E. | -11°57' -30°41' | | | | -67°28'174°51' R. | -21°06' S.E. | -9°23' -30°29' | | | | -67°28'174°51' T. | -26°53' S.S.E. | -5°11' -32°04' | | | | -67°29'174°51' R. | -29°42' S. ¾ E. | -2°01' -31°43' | | | | -67°30'174°51' R. | -26°31' S.S.E. | -5°11' -31°42' | | | 6 A.M. | -67°50'175°00' O. | -29°01' S.S.E. | -5°33' -34°34' | | | | -67°50'175°00' S. | -29°09' S.S.E. | -5°33' -34°42' | | | | -67°52'175°01' S. | -31°48' S.S.E. | -5°33' -37°21' | | | | -67°52'175°01' O. | -27°53' S.S.E. | -5°33' -33°26' | | | | -68°00'175°00' T. | -26°11' S.S.E. ½ E. | -6°46' -32°57' | | | | -68°00'175°00' Y. | -27°00' S.S.E. | -5°33' -32°33' | | | | -68°00'175°00' S. | -27°01' S.S.E. | -5°33' -32°34' | | | | -68°00'175°00' T. | -27°42' S.S.E. | -5°33' -33°15' | | | | -68°05'175°10' W. | -26°58' S.S.E. ½ E. | -6°46' -33°44' | | | | -68°05'175°10' T. | -28°18' S.S.E. | -5°33' -33°51' | | | | -68°05'175°14' R. | -29°51' S.S.E. | -5°33' -35°24' | | | | -68°05'175°14' R. | -43°7' N.W. | +9°09' -34°38' | | | | -68°12'175°14' R. | -24°56' S.E. ½ S. | -9°02' -33°58' | ### Observations of Declination. (Continued.) | Year | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|----------------------|----------------|---------| | 1841 | Jan. 7 P.M. | -68° 32' | T. -46° 02' | W. 3/4 N. | +13° 25' | -32° 37' | 0° | | | | | | -68° 32' | T. -47° 05' | W. by s. 1/2 s. | +13° 20' | -33° 45' | | | | | | | -68° 32' | W. -46° 07' | W. by s. | +13° 39' | -32° 28' | | | | | | | -68° 32' | Sm. -24° 06' | S.E. 1/2 E. | -11° 02' | -35° 08' | | | | | | | -68° 32' | T. -46° 57' | W. by s. | +13° 39' | -33° 18' | | | | | | | -68° 32' | R. -25° 49' | S.E. 1/2 S. | -9° 12' | -35° 01' | | | | | | | -68° 32' | R. -47° 29' | W. by s. 1/2 s. | +13° 20' | -34° 09' | | | | | | | -68° 32' | T. -30° 21' | E. by s. 3/4 E. | -5° 30' | -35° 51' | | | | | | | -68° 30' | T. -20° 22' | S.E. by E. 1/2 E. | -12° 44' | -33° 06' | | | | | | | -68° 30' | S. -20° 51' | E. 3/4 N. | -13° 25' | -34° 16' | | | | | | | -68° 30' | T. -20° 22' | E. by s. 3/4 s. | -13° 10' | -33° 32' | | | | | | | -68° 30' | Y. -19° 58' | E. by s. 3/4 s. | -13° 20' | -33° 18' | | | | | | | -68° 28' | R. -34° 39' | | | | | | | | | | -68° 55' | S. -29° 26' | S.S.E. | -5° 45' | -35° 11' | | | | | | | -68° 55' | Y. -29° 38' | S.S.E. | -5° 45' | -35° 23' | | | | | | | -68° 55' | O. -28° 49' | S.S.E. | -5° 45' | -34° 34' | | | | | | | -68° 55' | T. -29° 09' | S.S.E. | -5° 45' | -34° 54' | | | | | | | -68° 55' | W. -29° 04' | S.S.E. | -5° 45' | -34° 49' | | | | | | | -70° 31' | R. -41° 12' | | | | | | | | | | -70° 32' | R. -47° 04' | S. 27° W. | 0° 00' | -41° 12' | | | | | | | -70° 34' | R. -47° 35' | S. 25° W. | +8° 34' | -38° 30' | | | | | | | -70° 34' | S. -49° 34' | S.S.W. 1/2 W. | +8° 00' | -39° 35' | | | | | | | -70° 34' | R. -59° 05' | W. | +8° 43' | -40° 51' | | | | | | | -70° 34' | R. -49° 12' | S.W. | +17° 50' | -41° 12' | | | | | | | -70° 52' | T. -44° 19' | | | | | | | | | | -70° 52' | Y. -44° 35' | S. | 0° 00' | -44° 19' | | | | | | | -70° 55' | Sm. -45° 31' | S. | 0° 00' | -44° 35' | | | | | | | -71° 02' | T. -43° 11' | S. | 0° 00' | -45° 31' | | | | | | | -71° 02' | Sm. -43° 48' | S. | 0° 00' | -43° 11' | | | | | | | -71° 02' | T. -46° 48' | S. 1/2 W. | 0° 00' | -43° 28' | | | | | | | -71° 02' | S. -43° 43' | S. | 0° 00' | -43° 43' | | | | | | | -71° 02' | O. -44° 36' | S. 1/2 W. | 0° 00' | -42° 28' | | | | | | | -71° 12' | R. -43° 29' | S. | 0° 00' | -43° 29' | | | | | | | -71° 21' | R. -48° 45' | S. by w. | +4° 20' | -44° 25' | | | | | | | -71° 21' | T. -50° 10' | S. by w. 1/2 W. | +6° 28' | -43° 42' | | | | | | | -71° 21' | W. -47° 35' | S. by w. 1/2 W. | +6° 28' | -41° 07' | | | | | | | -71° 21' | Y. -51° 03' | S. by w. 1/2 W. | +6° 28' | -44° 35' | | | | | | | -71° 22' | T. -51° 09' | S. by w. 1/2 W. | +6° 28' | -44° 41' | | | | | | | -71° 22' | S. -47° 45' | S. by w. | +4° 20' | -43° 25' | | | | | | | -71° 22' | O. -49° 33' | S. by w. 1/2 W. | +6° 28' | -43° 05' | | | | | | | -71° 24' | T. -51° 42' | S. by w. 1/2 W. | +6° 28' | -45° 14' | | | | | | | -71° 24' | S. -59° 57' | S.W. | +15° 50' | -44° 07' | | | | | | | -71° 19' | T. -28° 17' | N.E. by E. | -17° 36' | -45° 53' | | | | | | | -71° 52' | S. -27° 44' | N.E. 1/2 N. | -13° 38' | -41° 22' | | | | | | | -71° 52' | W. -30° 36' | N.E. 1/2 N. | -13° 38' | -44° 14' | | | | | | | -72° 07' | S. -27° 40' | E. by n. 1/2 N. | -21° 06' | -48° 46' | | | | | | | -71° 46' | O. -49° 22' | S. by w. 1/2 W. | +6° 40' | -42° 42' | | | | | | | -71° 46' | S. -48° 22' | S. by w. 1/2 W. | +6° 40' | -41° 42' | | | | | | | -71° 46' | T. -51° 34' | S. by w. 1/2 W. | +6° 40' | -44° 54' | | | | | | | -71° 46' | S. -51° 24' | S.S.W. | +8° 52' | -42° 32' | | | | | | | -71° 54' | T. -24° 13' | E. by s. | -22° 11' | -46° 24' | | | | | | | -71° 54' | R. -24° 51' | E. by s. | -22° 11' | -47° 03' | | | | | | | -71° 54' | T. -25° 00' | E. by s. | -22° 11' | -47° 11' | | | | | | | -71° 54' | W. -23° 32' | E. by s. 1/2 s. | -21° 36' | -45° 08' | | | | | | | -71° 55' | R. -24° 15' | E. 1/2 s. | -22° 19' | -46° 34' | | | | * $\psi'$ at West = $-59° 05'$ $\psi'$ at South = $-41° 12'$ Diff. $17° 53'$ = ship's attraction at West: $$\frac{\sin 17° 53'}{a} = \tan \theta; \quad \frac{\sin 17° 53'}{0.267} = 1.150 = \tan 85° 02'.$$ ## Observations of Declination. (Continued.) | Date | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------------|----------|----------|----------------------|--------------------------|-------------|---------------------------------|----------------------|-----------------|---------| | Jan. 15 P.M. | | | | | | | | | | | Lat. | Long. | | | | | | | | | | -71° 53' 17" 01' S. | -29° 28' | E. ½ S. | -86° 00' | -22° 19' -51° 47' | -48° 12' | | | | | | -71° 53' 17" 01' O. | -27° 43' | E. ¾ N. | | -22° 00' -49° 43' | | | | | | | -71° 53' 17" 01' T. | -25° 33' | E. ¼ N. | | -22° 08' -47° 41' | | | | | | | -71° 53' 17" 01' W. | -26° 08' | E. | | -22° 27' -48° 35' | | | | | | | -71° 58' 17" 36' R. | -59° 31' | S.S.W. ½ W. | | +10° 50' -48° 41' | | | | | | | -72° 00' 17" 32' R. | -26° 05' | E. ½ S. | | -22° 19' -48° 24' | | | | | | | 17 P.M. | | | | | | | | | | | -72° 14' 17" 40' W. | -33° 28' | S.E. by E. | | -19° 02' -52° 30' | | | | | | | -72° 15' 17" 02' T. | -31° 37' | S.E. ¾ E. | | -18° 20' -49° 57' | | | | | | | -72° 16' 17" 10' T. | -32° 41' | S.E. ½ E. | | -17° 40' -50° 21' | | | | | | | -72° 17' 17" 14' T. | -35° 05' | S.E. ¼ E. | | -17° 40' -52° 45' | | | | | | | -72° 17' 17" 14' S. | -35° 58' | S.E. ½ E. | | -17° 40' -53° 38' | | | | | | | -72° 17' 17" 14' O. | -33° 15' | S.E. ¾ E. | | -17° 40' -50° 55' | | | | | | | 18 P.M. | | | | | | | | | | | -73° 00' 17" 14' R. | -35° 12' | E.S.E. | | -22° 02' -57° 14' | | | | | | | -73° 02' 17" 10' T. | -65° 04' | S.W. by s. | | +13° 23' -51° 41' | | | | | | | -73° 02' 17" 10' R. | -64° 35' | S.W. by s. | | +13° 23' -51° 12' | | | | | | | -73° 02' 17" 10' S. | -65° 52' | S.W. by s. | | +13° 23' -52° 29' | | | | | | | -73° 02' 17" 10' O. | -65° 50' | S.S.W. ½ W. | | +11° 18' -54° 32' | | | | | | | -73° 02' 17" 03' R. | -65° 54' | S.W. by s. | | +13° 23' -52° 31' | | | | | | | -73° 02' 17" 03' T. | -68° 09' | S.W. ½ S. | | +15° 11' -52° 58' | | | | | | | -73° 02' 17" 03' R. | -65° 02' | S.S.W. ½ W. | | +11° 18' -53° 44' | | | | | | | -73° 02' 17" 51' R. | -63° 34' | S.S.W. ½ W. | | +11° 18' -52° 16' | | | | | | | -73° 01' 17" 38' R. | -63° 37' | S.W. by s. | | +13° 23' -50° 14' | | | | | | | -73° 00' 17" 24' R. | -62° 45' | S.S.W. ½ W. | | +11° 18' -51° 27' | | | | | | | -72° 59' 17" 11' R. | -64° 15' | S.S.W. ¼ W. | | +12° 22' -51° 53' | | | | | | | 19 A.M. | | | | | | | | | | | -72° 36' 17" 40' T. | -66° 21' | S.W. | | +16° 15' -50° 06' | | | | | | | -72° 36' 17" 40' W. | -66° 12' | S.W. ½ W. | | +17° 37' -48° 35' | | | | | | | -72° 36' 17" 40' Y. | -64° 49' | S.W. by s. | | +12° 49' -52° 00' | | | | | | | -72° 36' 17" 40' T. | -64° 11' | S.W. ¾ S. | | +13° 45' -50° 26' | | | | | | | -72° 35' 17" 39' T. | -67° 43' | S.W. | | +16° 15' -51° 28' | | | | | | | 19 P.M. | | | | | | | | | | | -72° 31' 17" 40' O. | -53° 57' | N. by W. ½ W. | | +6° 27' -47° 30' | | | | | | | -72° 34' 17" 42' T. | -43° 53' | S. by E. ½ E. | | -6° 55' -50° 48' | | | | | | | -72° 34' 17" 42' T. | -44° 43' | S. by E. ½ E. | | -6° 55' -51° 38' | | | | | | | -72° 34' 17" 45' Y. | -41° 10' | S.S.E. | | -9° 14' -50° 24' | | | | | | | -72° 34' 17" 45' O. | -43° 34' | S.S.E. | | -9° 14' -52° 48' | | | | | | | -72° 34' 17" 45' R. | -43° 43' | S.S.E. | | -9° 14' -52° 57' | | | | | | | -72° 36' 17" 40' R. | -48° 22' | S. by E. | | -4° 39' -53° 01' | | | | | | | -72° 50' 17" 10' R. | -49° 15' | S. by E. ½ E. | | -6° 55' -56° 10' | | | | | | | 21 A.M. | | | | | | | | | | | -74° 10' 16" 28' S. | -34° 25' | E. ½ S. | | -28° 37' -63° 02' | | | | | | | -74° 10' 16" 28' O. | -31° 47' | E. ¼ S. | | -28° 53' -60° 40' | | | | | | | -73° 53' 17" 57' S. | -88° 12' | W. by N. ½ N. | | -28° 37' -61° 01' | | | | | | | -73° 53' 17" 57' S. | -78° 56' | N.N.W. | | +10° 28' -68° 28' | | | | | | | -73° 53' 17" 57' S. | -35° 43' | E. by N. | | -28° 08' -63° 51' | | | | | | | -73° 57' 17" 40' T. | -48° 46' | N.N.E. ¾ E. | | -14° 12' -62° 58' | | | | | | | -73° 57' 17" 40' T. | -38° 00' | E. by N. | | -28° 08' -66° 08' | | | | | | | -73° 57' 17" 40' T. | -36° 56' | E. ½ N. | | -28° 22' -65° 18' | | | | | | | -73° 54' 17" 55' Y. | -37° 13' | E. by s. | | -28° 29' -65° 42' | | | | | | | -73° 54' 17" 55' T. | -35° 59' | E. by s. ½ S. | | -27° 41' -63° 40' | | | | | | | -73° 54' 17" 00' O. | -31° 25' | E. by s. ½ S. | | -27° 41' -59° 06' | | | | | | | -73° 55' 17" 04' O. | -36° 52' | E.S.E. | | -26° 53' -63° 45' | | | | | | | 22 P.M. | | | | | | | | | | | -73° 58' 17" 16' S. | -61° 29' | S. | | 0° 00' -61° 29' | | | | | | | -73° 59' 17" 58' S. | -65° 50' | S. by w. | | +5° 39' -60° 11' | | | | | | | -73° 59' 17" 58' T. | -67° 45' | S. ½ W. | | +2° 49' -64° 56' | | | | | | | -74° 00' 17" 43' R. | -66° 08' | S. by w. | | +5° 39' -60° 29' | | | | | | | -74° 00' 17" 43' R. | -69° 22' | S. by w. | | +5° 39' -63° 43' | | | | | | | -74° 01' 17" 34' R. | -38° 31' | E. ½ S. | | -28° 45' -67° 16' | | | | | | | -74° 04' 17" 27' R. | -40° 04' | E. by s. ½ S. | | -27° 41' -67° 45' | | | | | | | -74° 04' 17" 27' T. | -36° 00' | E. ¾ S. | | -28° 37' -64° 37' | | | | | | | -74° 04' 17" 27' W. | -38° 52' | E. ½ N. | | -28° 33' -67° 25' | | | | | | | -74° 04' 17" 27' T. | -37° 46' | E. by s. | | -28° 29' -66° 15' | | | | | | ### Observations of Declination. (Continued.) | Year | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|----------------------|----------------|---------| | 1841 | Jan. 25 A.M. | T. | -78° 32' S. by W. ½ W. | +9° 21' | -69° 11' | +9° 21' | -68° 15' | -31° 38' | -68° 55' | | | | T. | -77° 36' S. by W. ½ W. | +9° 21' | -68° 15' | -31° 38' | -66° 32' | -29° 07' | -66° 47' | | | | T. | -37° 17' S.E. by E. ¾ E. | -32° 28' | -71° 43' | -30° 45' | -70° 39' | -30° 00' | -73° 14' | | | | Y. | -39° 15' E.S.E. | -30° 00' | -73° 14' | -30° 00' | -73° 14' | -30° 00' | -73° 14' | | | | SM. | -39° 54' S.E. by E. ¼ E. | -30° 00' | -73° 14' | -30° 00' | -73° 14' | -30° 00' | -73° 14' | | | | T. | -43° 14' S.E. by E. ¼ E. | -30° 00' | -73° 14' | -30° 00' | -73° 14' | -30° 00' | -73° 14' | | | | R. | -81° 36' S.S.W. | +12° 23' | -69° 13' | +12° 23' | -68° 45' | +15° 13' | -71° 15' | | | | R. | -81° 08' S.S.W. | +12° 23' | -68° 45' | +12° 23' | -74° 56' | +12° 23' | -74° 56' | | | | R. | -86° 28' S.S.W. ½ W. | +15° 13' | -71° 15' | +15° 13' | -70° 22' | +15° 13' | -70° 22' | | | | S. | -87° 19' S.S.W. | +15° 13' | -70° 22' | +15° 13' | -71° 08' | +15° 13' | -71° 08' | | | | T. | -85° 35' S. by W. ½ W. | +15° 13' | -71° 08' | +15° 13' | -71° 08' | +15° 13' | -71° 08' | | | | R. | -85° 15' S.S.W. | +15° 13' | -71° 08' | +15° 13' | -71° 08' | +15° 13' | -71° 08' | | | | R. | -93° 49' S.W. ½ W. | +25° 10' | -68° 39' | +25° 10' | -70° 28' | +20° 33' | -70° 28' | | | | T. | -91° 01' S.W. by S. | +25° 10' | -68° 39' | +25° 10' | -68° 49' | +18° 03' | -76° 06' | | | | R. | -43° 39' S.E. ½ E. | +18° 03' | -76° 06' | +18° 03' | -76° 06' | +18° 03' | -76° 06' | | | | T. | -94° 09' S.W. by S. | +18° 03' | -76° 06' | +18° 03' | -76° 06' | +18° 03' | -76° 06' | | | | T. | -77° 04' S.S.E. | -15° 04' | -90° 53' | -15° 04' | -92° 08' | +18° 32' | -82° 23' | | | | R. | -100° 55' S.S.W. ½ W. | +15° 04' | -82° 23' | +15° 04' | -84° 02' | +15° 04' | -84° 02' | | | | R. | -100° 26' S.S.W. | +15° 04' | -84° 02' | +15° 04' | -84° 02' | +15° 04' | -84° 02' | | | | Y. | -99° 06' S.S.W. | +15° 04' | -84° 02' | +15° 04' | -84° 02' | +15° 04' | -84° 02' | | | | T. | -45° 19' E.S.E. | -37° 42' | -83° 01' | -37° 42' | -83° 01' | -37° 42' | -83° 01' | | | | R. | -46° 18' S.E. by E. ½ E. | -35° 40' | -81° 58' | -35° 40' | -81° 58' | -35° 40' | -81° 58' | | | | S. | -47° 55' S.E. by E. ½ E. | -35° 40' | -81° 58' | -35° 40' | -81° 58' | -35° 40' | -81° 58' | | | | R. | -47° 41' S.E. by E. | -33° 37' | -81° 18' | -33° 37' | -81° 18' | -33° 37' | -81° 18' | | | | SM. | -104° 19' N. ½ E. | -2° 48' | -107° 07' | -2° 48' | -107° 07' | -2° 48' | -107° 07' | | | | T. | -105° 44' N. ¼ W. | +1° 24' | -104° 20' | +1° 24' | -104° 20' | +1° 24' | -104° 20' | | | | T. | -114° 11' N.by W. ½ W. | +8° 20' | -105° 51' | +8° 20' | -105° 15' | +13° 38' | -105° 15' | | | | T. | -118° 53' N.N.W. ½ W. | +8° 20' | -105° 15' | +8° 20' | -100° 00' | +8° 20' | -100° 00' | | | | S. | -108° 20' N.by W. ½ W. | +8° 20' | -100° 00' | +8° 20' | -108° 06' | +4° 12' | -100° 18' | | | | T. | -116° 26' N.by W. ½ W. | +4° 12' | -100° 18' | +4° 12' | -100° 18' | +4° 12' | -100° 18' | | | | T. | -104° 30' N. ¾ E. | -15° 22' | -106° 16' | -15° 22' | -106° 16' | -15° 22' | -106° 16' | | | | T. | -90° 54' S.E. by S. | +1° 15' | -103° 37' | +1° 15' | -103° 37' | +1° 15' | -103° 37' | | | | T. | -104° 52' N. ¼ W. | +2° 30' | -107° 37' | +2° 30' | -107° 37' | +2° 30' | -107° 37' | | | | R. | -110° 07' N. ½ W. | -3° 45' | -103° 55' | -3° 45' | -103° 55' | -3° 45' | -103° 55' | | | | R. | -100° 10' N. ¾ E. | -10° 04' | -96° 17' | -10° 04' | -96° 17' | -10° 04' | -96° 17' | | | | S. | -106° 52' N.N.W. ½ W. | +10° 35' | -96° 17' | +10° 35' | -96° 17' | +10° 35' | -96° 17' | | | | T. | -70° 55' N.E. by E. ¼ E. | -13° 39' | -84° 34' | -13° 39' | -84° 34' | -13° 39' | -84° 34' | | | | T. | -60° 57' N.E. by E. ¼ E. | -19° 13' | -80° 10' | -19° 13' | -80° 10' | -19° 13' | -80° 10' | | | | T. | -66° 38' N.E. by N. | -11° 58' | -78° 36' | -11° 58' | -78° 36' | -11° 58' | -78° 36' | | | | SM. | -68° 56' N.N.E. | -8° 10' | -77° 06' | -8° 10' | -77° 06' | -8° 10' | -77° 06' | | | | S. | -72° 35' N.N.E. ½ E. | -10° 04' | -82° 39' | -10° 04' | -82° 39' | -10° 04' | -82° 39' | | | | R. | -74° 06' N.N.E. ½ E. | -10° 04' | -84° 10' | -10° 04' | -84° 10' | -10° 04' | -84° 10' | | | | SM. | -103° 58' S.W.by W. ¾ W. | +20° 02' | -83° 56' | +20° 02' | -83° 56' | +20° 02' | -83° 56' | | | | T. | -102° 56' S.W. by W. | +19° 02' | -83° 54' | +19° 02' | -83° 54' | +19° 02' | -83° 54' | | | | T. | -103° 52' W.by S. ½ S. | +21° 36' | -82° 16' | +21° 36' | -82° 16' | +21° 36' | -82° 16' | | | | T. | -90° 06' N.N.W. | +8° 10' | -81° 56' | +8° 10' | -81° 56' | +8° 10' | -81° 56' | | | | S. | -73° 58' S.E. by S. | -12° 49' | -83° 47' | -12° 49' | -83° 47' | -12° 49' | -83° 47' | | | | R. | -85° 52' S.E. by E. | -12° 49' | -86° 47' | -12° 49' | -86° 47' | -12° 49' | -86° 47' | | | | R. | -84° 25' S.S.E. | -4° 17' | -90° 09' | -4° 17' | -90° 09' | -4° 17' | -90° 09' | | | | R. | -79° 49' S.E. by S. | -8° 30' | -92° 55' | -8° 30' | -92° 55' | -8° 30' | -92° 55' | | | | R. | -66° 58' E. ¼ S. | -12° 18' | -92° 07' | -12° 18' | -92° 07' | -12° 18' | -92° 07' | | | | R. | -66° 58' E. ¼ S. | -21° 27' | -88° 25' | -21° 27' | -88° 25' | -21° 27' | -88° 25' | | | | R. | -66° 58' E. ¼ S. | -91° 07' | ### Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|---------------------------|-------------|---------------------------------|----------------------|----------------|---------| | Feb. 1 P.M. | Lat. | Long. | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | | -77° 09' 188 24" R. | -70° 19' E.S.E. | -85° 50' | -20° 13' -90° 32' | -91° 07' | | -77° 09' 188 24" R. | -75° 38' S.E. | -15° 37' -91° 15' | | -77° 09' 188 24" R. | -82° 22' S.S.E. | -8° 30' -90° 52' | | -77° 09' 188 15" T. | -79° 56' S.E. by S. | -12° 18' -92° 14' | | -77° 09' 188 15" T. | -79° 14' S.E. by S. | -12° 18' -91° 32' | | 2 A.M. | -77° 34' 186 56" S. | -72° 39' E.S.E. | -22° 02' -94° 41' | | -77° 34' 186 03" O. | -70° 42' S.E.by E.½ E. | -20° 58' -91° 40' | | -77° 34' 186 15" S. | -69° 05' E. | -23° 36' -92° 41' | | -77° 34' 186 15" O. | -71° 39' E.S.E. | -22° 02' -93° 41' | | -77° 35' 186 55" T. | -72° 32' S.E.by E.¼ E. | -20° 27' -92° 59' | | -77° 35' 186 55" T. | -73° 09' S.E.by E.½ E. | -20° 58' -94° 07' | | -77° 35' 186 55" T. | -75° 37' S.E. | -17° 00' -92° 37' | | -77° 35' 186 55" S. | -76° 49' S.E. | -17° 00' -93° 49' | | 2 P.M. | -77° 43' 186 50" W. | -72° 04' E.S.E. | -22° 02' -94° 06' | | -77° 43' 187 00" R. | -69° 50' S.E.by E. | -19° 55' -89° 45' | | -77° 43' 187 00" R. | -72° 25' S.E.by E.½ E. | -20° 58' -93° 23' | | -77° 47' 186 52" T. | -69° 57' S.E.by E.½ S. | -22° 39' -92° 36' | | -77° 47' 186 52" Sm. | -72° 53' E.S.E. | -22° 02' -94° 55' | | -77° 47' 186 52" R. | -73° 10' E.S.E. | -22° 02' -95° 12' | | -77° 47' 186 52" R. | -72° 56' E.by S.½ S. | -22° 39' -95° 35' | | -77° 46' 186 51" S. | -74° 47' E.S.E. | -22° 02' -96° 49' | | -77° 46' 186 51" T. | -74° 38' S.E.by E.½ E. | -20° 58' -95° 36' | | -77° 47' 186 51" R. | -75° 01' E.S.E. | -22° 02' -97° 03' | | -77° 56' 186 51" R. | -74° 22' E. | -23° 36' -97° 58' | | -77° 56' 186 51" T. | -72° 32' E.½ N. | -23° 16' -95° 48' | | -77° 57' 186 44" R. | -71° 21' E. | -23° 36' -94° 57' | | -77° 57' 186 44" R. | -75° 38' E.N.E. | -21° 23' -97° 01' | | -77° 57' 186 44" T. | -74° 27' E.¼ N. | -23° 26' -97° 53' | | -77° 59' 186 47" R. | -72° 03' E. | -23° 36' -95° 39' | | -78° 00' 186 45" R. | -72° 10' E.S.E. | -22° 02' -94° 12' | | 3 A.M. | -77° 32' 186 00" Sm. | -117° 40' W.by S.½ S. | +22° 40' -95° 00' | | -77° 32' 186 00" T. | -118° 47' W.S.W. | +22° 02' -96° 45' | | 4 A.M. | -77° 05' 192 32" S. | -77° 52' S.by E. | -4° 18' -82° 10' | | -77° 05' 192 32" T. | -77° 44' S.½ E. | -1° 04' -78° 48' | | -77° 06' 192 33" O. | -76° 31' S.¼ E. | -2° 08' -78° 39' | | -77° 54' 192 30" Y. | -62° 21' E.N.E. | -19° 31' -81° 52' | | -77° 54' 192 30" S. | -60° 36' E.N.E. | -19° 31' -80° 07' | | -77° 54' 192 30" O. | -63° 11' N.E.by E. | -17° 24' -80° 35' | | -76° 57' 192 37" T. | -59° 54' N.E.by E.½ E. | -18° 27' -78° 21' | | 4 P.M. | -77° 6' 192 34" R. | -61° 29' E.by N.½ N. | -19° 24' -80° 53' | | -77° 9' 192 43" R. | -62° 14' E.by N. | -20° 04' -82° 18' | | -77° 9' 192 43" T. | -62° 31' E.by N. | -20° 04' -82° 35' | | -77° 13' 192 51" R. | -68° 53' E.by N.½ N. | -19° 24' -88° 17' | | -77° 13' 192 51" T. | -67° 45' N.E.by E.½ E. | -18° 13' -85° 58' | | -77° 13' 192 49" R. | -93° 17' S.S.W.½ W. | +10° 00' -83° 17' | | 5 A.M. | -77° 24' 192 56" S. | -81° 22' S. | 0° 00' -81° 22' | | -77° 8' 192 59" O. | -63° 33' E. | -20° 38' -84° 11' | | -77° 8' 192 59" T. | -77° 06' S.by E. | -4° 08' -81° 14' | | -77° 8' 192 59" T. | -83° 12' S. | 0° 00' -83° 12' | | -77° 8' 192 59" T. | -92° 23' S.S.W.½ W. | +10° 01' -82° 22' | | -77° 8' 192 59" W. | -92° 16' S.S.W.½ W. | +10° 01' -82° 15' | | 5 P.M. | -77° 19' 192 50" T. | -83° 00' S.¼ W. | +1° 00' -82° 00' | | -77° 16' 191 32" R. | -89° 26' S.by W.½ W. | +6° 10' -83° 16' | | -77° 16' 191 32" R. | -80° 06' S.by E.½ E. | -6° 10' -86° 16' | | -77° 16' 191 32" R. | -70° 42' S.E.½ S. | -13° 26' -84° 08' | | -77° 16' 191 32" R. | -63° 24' E.½ S. | -20° 30' -83° 54' | | -77° 16' 191 32" R. | -66° 30' S.E.by E. | -17° 34' -84° 04' | ## Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | |------|----------|----------|----------------------|--------------------------|------------|---------------------------------|---------------------|------------------| | Feb. 6 A.M. | Lat. | Long. | S. | 87° 49' | s. by w. | + 4° 28' | 83° 21' | | | -77° 14' | 19° 2 | S. | 88 18 | s. by w. | + 4° 28' | 83° 50 | | | -77° 05' | 18° 2 | T. | 83 07 | s. 3/4 W. | + 3° 20' | 79° 47 | -82° 09 | | -77° 09' | 18° 50 | SM. | 85 52 | s. 3/4 W. | + 3° 20' | 82° 32 | | | -77° 09' | 18° 50 | T. | 58 23 | E. by N. | -21° 50' | 80° 13 | | | -77° 04' | 18° 40 | T. | 80 58 | s. 1/2 E. | -2° 14' | 83° 12 | | | 7 A.M. | -76° 58' | 18° 40 | T. | 94 54 | S.S.W. 1/4 W. | +10° 02' | 84° 52' | | | -76° 58' | 18° 40 | T. | 91 17 | S.S.W. | +9° 02' | 82° 15 | | | -76° 58' | 18° 40 | T. | 87 10 | S.W. by N. 1/2 W. | +6° 45' | 80° 25 | | | -76° 58' | 18° 40 | T. | 59 46 | E. 1/2 S. | -22° 52' | 82° 38 | -81° 33 | | -76° 56' | 18° 39 | S. | 59 16 | E. 1/2 S. | -22° 52' | 82° 08 | | | -76° 56' | 18° 39 | O. | 56 07 | E. 1/2 N. | -22° 53' | 79° 00 | | | -76° 56' | 18° 39 | T. | 57 38 | E. 1/2 S. | -22° 52' | 80° 30 | | | -76° 56' | 18° 39 | O. | 57 12 | E. by S. | -22° 43' | 79° 55 | | | -76° 57' | 18° 36 | S. | 60 09 | E. by S. 1/2 S. | -22° 06' | 82° 15 | | | 7 P.M. | -77° 11' | 18° 03 | T. | 68 38 | E. by S. 1/4 S. | -21° 54' | 80° 32' | | | -77° 11' | 18° 03 | R. | 68 31 | E. by S. 1/2 S. | -21° 36' | 90° 07 | | | -77° 12' | 18° 03 | T. | 70 01 | S.E.by E. 1/2 E. | -20° 02' | 90° 03 | | | -77° 12' | 18° 03 | T. | 66 16 | S.E.by E. | -19° 02' | 85° 18 | | | -77° 12' | 18° 03 | R. | 67 27 | S.E.by E. | -19° 02' | 86° 29 | -87° 29 | | -77° 12' | 18° 03 | R. | 81 21 | S.S.E. | -8° 52' | 90° 13 | | | -77° 14' | 18° 01 | R. | 74 43 | S.E.by S. | -12° 49' | 87° 32 | | | -77° 14' | 18° 01 | R. | 72 20 | S.E. | -16° 15' | 88° 35 | | | -77° 14' | 18° 01 | T. | 72 00 | S.E. | -16° 15' | 88° 15 | | | -77° 13' | 18° 54 | W. | 71 29 | S.E. | -16° 15' | 87° 44 | | | 8 A.M. | -77° 24' | 18° 19 | S. | 65 24 | E.S.E. | -21° 02' | 86° 26 | | | -77° 24' | 18° 19 | O. | 65 32 | E.S.E. | -21° 02' | 86° 34 | | | -77° 21' | 18° 22 | T. | 68 19 | E.by S. 1/2 S. | -21° 37' | 89° 56 | -89° 19 | | -77° 21' | 18° 22 | Y. | 67 35 | E. 1/2 S. | -22° 19' | 89° 54 | | | -77° 21' | 18° 22 | Y. | 71 43 | E.S.E. | -21° 02' | 92° 45 | | | -77° 21' | 18° 22 | T. | 69 19 | E.S.E. | -21° 02' | 90° 21 | | | -77° 21' | 18° 22 | O. | 67 29 | E.S.E. | -21° 02' | 88° 31 | | | -77° 21' | 18° 22 | S. | 67 38 | E.S.E. | -21° 02' | 88° 40 | | | -77° 30' | 18° 40 | T. | 71 42 | E.S.E. | -21° 02' | 91° 44 | -90° 21 | | -77° 30' | 18° 40 | W. | 70 31 | E.S.E. | -21° 02' | 91° 33 | | | -77° 30' | 18° 40 | T. | 69 39 | E. | -22° 27' | 92° 06 | | | -77° 37' | 18° 36 | R. | 67 40 | E.by N. | -21° 50' | 89° 30 | | | 8 P.M. | -77° 47' | 18° 18 | R. | 72 51 | E.by N. 1/2 N. | -21° 6' | 93° 57 | | | -77° 47' | 18° 10 | S. | 74 04 | E.N.E. | -20° 23' | 94° 27 | | | -77° 48' | 18° 29 | O. | 74 17 | E.N.E. | -20° 23' | 94° 40 | -95° 52 | | -77° 48' | 18° 29 | T. | 75 35 | E.N.E. | -20° 23' | 95° 58 | | | -77° 50' | 18° 35 | T. | 76 38 | N.E.by E. 1/2 E. | -19° 18' | 95° 56 | | | -77° 50' | 18° 35 | W. | 79 50 | E.N.E. | -20° 23' | 100° 13 | | | -77° 49' | 18° 25 | R. | 76 04 | E.N.E. | -20° 23' | 96° 27 | | | -77° 49' | 18° 25 | T. | 79 29 | N.E.by E. | -18° 11' | 97° 40 | | | -77° 50' | 18° 31 | R. | 75 32 | N.E.by E. | -18° 11' | 93° 43 | -96° 00 | | -77° 51' | 18° 36 | R. | 77 19 | N.E.by E. 1/2 E. | -19° 18' | 96° 37 | | | -77° 53' | 18° 44 | R. | 80 42 | N.E. | -15° 20' | 96° 02 | | | -77° 57' | 18° 06 | T. | 95 31 | N. | 0° 00' | 95° 31 | | | 9 A.M. | -77° 52' | 19° 16 | W. | 108 01 | S.W. 1/2 S. | +13° 57' | 94° 04 | | | -77° 52' | 19° 16 | T. | 109 17 | S.W. 1/2 S. | +13° 57' | 95° 20 | | | -77° 52' | 19° 07 | Y. | 108 43 | S.W. 1/2 S. | +13° 57' | 94° 46 | -93° 43 | | -77° 52' | 19° 07 | T. | 103 50 | S.W.by S. | +12° 18' | 91° 32 | | | -77° 48' | 19° 23 | T. | 101 26 | S.S.W. | +8° 30' | 92° 56 | | ### Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|-------------|---------------------------------|---------------------|----------------|---------| | Feb. 9 P.M. | Lat. | Long. | R. | -102° 30' | s.s.w. | + 8° 52' | 93° 38' | | | | | -77° 56' | 188° 30' | R. | -110° 29' | s.w. ½ S. | +14° 32' | 95° 57' | | | | | -77° 56' | 188° 40' | R. | -106° 13' | s.s.w. ¾ W. | +11° 50' | 94° 23' | | | | | -77° 54' | 188° 36' | R. | -105° 51' | s.w. by S. | +12° 49' | 93° 02' | | | | | -77° 54' | 188° 36' | S. | -103° 13' | s.s.w. ½ W. | +10° 50' | 92° 23' | | | | | -77° 51' | 188° 24' | R. | -103° 18' | s.s.w. ½ W. | +10° 50' | 92° 28' | | | | | -77° 50' | 188° 06' | R. | -94° 04' | s. ¼ W. | +1° 04' | 93° 00' | | | | | -77° 50' | 188° 06' | S. | -94° 38' | s. | 0° 00' | 94° 38' | | | | 10 A.M. | -77° 35' | 187° 59' | S. | -94° 12' | s. | 0° 00' | 94° 12' | | | | | -77° 57' | 187° 38' | T. | -110° 56' | s.w. ½ W. | +17° 38' | 93° 18' | | | | | -77° 38' | 188° 07' | Y. | -97° 53' | s. by W. | +4° 28' | 93° 25' | | | | | -77° 38' | 188° 07' | T. | -101° 54' | s.s.w. | +8° 52' | 93° 02' | | | | | -77° 40' | 188° 00' | SM. | -108° 00' | s.w. by S. | +12° 49' | 95° 11' | | | | | -77° 48' | 188° 00' | S. | -108° 49' | s.w. by S. | +12° 49' | 96° 00' | | | | | -77° 48' | 188° 00' | O. | -105° 38' | s.w. ½ S. | +14° 32' | 91° 06' | | | | | -77° 48' | 188° 04' | T. | -106° 04' | s.w. by S. | +12° 49' | 93° 15' | | | | 11 A.M. | -76° 45' | 189° 06' | O. | -74° 47' | s. ½ E. | -1° 06' | 75° 53' | | | | | -76° 46' | 188° 40' | S. | -86° 56' | s.w. by W. | +6° 40' | 80° 16' | | | | | -76° 46' | 188° 40' | S. | -80° 11' | s. | 0° 00' | 80° 11' | | | | | -76° 46' | 188° 40' | S. | -95° 11' | s.w. ½ S. | +14° 32' | 80° 39' | | | | 11 P.M. | -76° 14' | 187° 11' | S. | -86° 06' | N.W. ½ N. | +13° 39' | 72° 27' | | | | 14 A.M. | -76° 23' | 178° 25' | S. | -98° 02' | s.w. by W. | +8° 50' | 89° 12' | | | | | -76° 24' | 176° 26' | R. | -91° 24' | s.w. by W. | +10° 17' | 81° 07' | | | | 15 P.M. | -76° 03' | 168° 56' | R. | -85° 31' | s.by E. ¼ E. | -10° 13' | 95° 44' | | | | | -76° 05' | 168° 56' | S. | -88° 32' | s.by E. ½ E. | -12° 13' | 100° 45' | | | | | -76° 05' | 168° 56' | O. | -86° 55' | s.by E. ¾ E. | -12° 13' | 99° 08' | | | | | -76° 16' | 168° 11' | R. | -85° 10' | s.by E. ¾ E. | -14° 13' | 99° 23' | | | | 16 A.M. | -76° 20' | 165° 33' | S. | -60° 54' | E. ½ N. | -45° 47' | 106° 41' | | | | | -76° 20' | 165° 33' | T. | -69° 12' | s.e. by E. | -37° 32' | 106° 44' | | | | | -76° 20' | 165° 33' | O. | -67° 08' | s.e. by E. | -37° 32' | 104° 40' | | | | | -76° 20' | 165° 33' | Y. | -65° 20' | E.S.E. | -42° 18' | 107° 38' | | | | | -76° 20' | 165° 33' | T. | -64° 59' | E.S.E. | -42° 18' | 107° 17' | | | | | -76° 30' | 166° 39' | R. | -58° 06' | E. | -46° 13' | 104° 19' | | | | 16 P.M. | -76° 35' | 166° 17' | R. | -64° 23' | s.by S. ½ S. | -44° 03' | 108° 26' | | | | | -76° 36' | 166° 17' | R. | -136° 19' | N.N.W. ½ W. | +19° 46' | 116° 33' | | | | | -76° 36' | 166° 17' | Y. | -150° 04' | N.W.W. | +41° 38' | 108° 26' | | | | | -76° 36' | 166° 16' | T. | -138° 24' | N.W. by N. | +23° 31' | 114° 53' | | | | | -76° 36' | 166° 16' | Y. | -158° 51' | W. | +46° 13' | 112° 38' | | | | | -76° 36' | 166° 16' | Y. | -156° 58' | s.by S. ½ S. | +44° 03' | 112° 55' | | | | | -76° 36' | 166° 16' | T. | -156° 05' | s.w. ¼ W. | +33° 04' | 123° 01' | | | | | -76° 36' | 166° 17' | R. | -154° 06' | s.w. by W. | +37° 32' | 116° 34' | | | | | -76° 36' | 166° 17' | R. | -142° 54' | s.w. ½ S. | +29° 45' | 113° 09' | | | | | -76° 37' | 166° 16' | R. | -67° 01' | E.N.E. | -41° 38' | 108° 39' | | | | | -76° 37' | 166° 16' | R. | -67° 53' | E. by S. | -45° 19' | 111° 51' | | | | | -76° 37' | 166° 16' | S. | -66° 32' | E. by S. | -45° 19' | 113° 12' | | | | | -76° 37' | 166° 16' | T. | -73° 45' | E.S.E. | -42° 18' | 116° 03' | | | | | -76° 37' | 166° 35' | R. | -73° 40' | s.e. by E. | -37° 32' | 111° 12' | | | * The inclination on the 16th of February is computed from the observed declinations with the head West = 158° 51', and E. by S. = 67° 12'. From these we have the approximate inclination $\theta = -87° 52'$. With this value of $\theta$, $\psi' = -66° 27'$ at East. Whence $\psi = \frac{-158° 51' + 66° 27'}{2} = -112° 39'$; $\delta$ at East or West = 46° 12'; and tan $\theta = \frac{\sin 46° 12'}{a} = \frac{0.7218}{0.0267} = -87° 53'$. Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|-------------|----------------------------------|----------------------|-----------------|---------| | Feb. 17 A.M. | -76° 44' | 165° 48' | S. -122° 02' | s. by w. | +9° 18' | -112° 44' | | | | | -76° 44' | 165° 48' | O. -123 18' | s. by w. | +9° 18' | -114° 00' | | | | | -76° 44' | 165° 48' | Y. -124 51' | s. by w. | +9° 18' | -115° 33' | | | | 17 P.M. | -76° 27' | 164° 18' | R. -113 59' | s. | -88° 05' | | | | | | -76° 27' | 164° 11' | R. -112 11' | s. | 0° 00' | -113° 59' | | | | | -76° 26' | 164° 02' | R. -73 51' | S.E. ½ E. | 0° 00' | -112° 11' | | | | | -76° 26' | 164° 02' | T. -71 53' | S.E.by E.½ E. | -38° 49' | -112° 40' | | | | | -76° 26' | 164° 02' | R. -73 51' | S.E. ½ E. | -43° 52' | -115° 45' | | | | | -76° 26' | 164° 02' | R. -73 51' | S.E. ½ E. | -38° 49' | -112° 40' | | | | 18 A.M. | -76° 16' | 165° 53' | T. -49 06' | E.by S. | -51° 20' | -100° 26' | | | | | -76° 16' | 165° 53' | T. -51 14' | E.by S.½ S. | -49° 37' | -100° 51' | | | | | -76° 05' | 166° 11' | T. -71 05' | N.E.by N. | -88° 04* | | | | | 18 P.M. | -76° 06' | 166° 11' | T. -152 46' | W. | -25° 56' | -97° 01' | | | | | -76° 03' | 166° 23' | S. -142 55' | W.W.W. | +52° 20' | -100° 26' | | | | | -76° 03' | 166° 23' | S. -144 38' | W.by N. | +46° 47' | -96° 08' | | | | | -75° 58' | 167° 04' | T. -71 05' | N.E.by N. | +51° 20' | -93° 18' | | | | | -75° 58' | 167° 04' | T. -149 32' | W. | +25° 56' | -97° 01' | | | | | -75° 49' | 167° 32' | R. -134 35' | S.W.by W. | +52° 20' | -97° 12' | | | | | -75° 45' | 167° 32' | R. -132 32' | S.W.by W. | +42° 07' | -92° 28' | | | | | -75° 42' | 167° 30' | S. -135 47' | S.W.by W. | +42° 07' | -90° 25' | | | | | -75° 42' | 167° 30' | R. -133 08' | S.W.½ W. | +42° 07' | -93° 40' | | | | 19 P.M. | -74° 46' | 167° 53' | R. -110 59' | S.W. | +37° 47' | -95° 21' | | | | | -74° 46' | 167° 53' | T. -107 01' | S.W. | +34° 12' | -76° 47' | | | | 22 P.M. | -70° 27' | 166° 40' | R. -18 35' | E.by S.½ S. | +34° 12' | -72° 49' | | | | | -70° 27' | 166° 40' | T. -16 21' | E.by N.½ N. | -20° 57' | -39° 32' | | | | 24 A.M. | -70° 14' | 168° 13' | Y. -50 20' | N.W.½ N. | -20° 13' | -36° 34' | | | | | -70° 14' | 168° 13' | T. -49 18' | N.W.½ N. | +13° 03' | -37° 17' | | | | 24 P.M. | -70° 24' | 167° 20' | S. -41 55' | S.½ E. | +13° 03' | -36° 15' | | | | | -70° 26' | 167° 19' | R. -42 49' | S. | -2° 08' | -44° 03' | | | | | -70° 26' | 167° 19' | O. -41 44' | S. | 0° 00' | -42° 49' | | | | 25 P.M. | -70° 07' | 167° 27' | R. -40 24' | S.½ W. | 0° 00' | -41° 44' | | | | | -70° 07' | 167° 27' | T. -40 16' | S.½ W. | +2° 08' | -38° 16' | | | | | -70° 06' | 167° 29' | R. -41 14' | S. | +2° 08' | -38° 08' | | | | | -70° 06' | 167° 29' | R. -44 06' | N.by W.½ W. | +6° 52' | -37° 14' | | | | | -70° 04' | 167° 32' | T. -49 16' | N.N.W. | +6° 52' | -37° 14' | | | | | -70° 04' | 167° 32' | T. -56 14' | N.W.by W.½ W. | +7° 50' | -41° 26' | | | | | -70° 02' | 167° 35' | R. -52 55' | N.W.by W. | +18° 27' | -37° 47' | | | | | -70° 02' | 167° 11' | S. -42 51' | S.by W. | +17° 24' | -35° 31' | | | | | -70° 03' | 167° 26' | R. -46 21' | S.by W. | +4° 17' | -38° 34' | | | | 26 A.M. | -69° 54' | 167° 56' | S. -61 35' | S.W.by W. | +4° 17' | -42° 04' | | | | 27 P.M. | -69° 17' | 168° 00' | R. -48 44' | N.W. | +18° 16' | -43° 19' | | | | | -69° 17' | 168° 00' | O. -50 39' | N.W.½ W. | +13° 27' | -35° 17' | | | | | -69° 16' | 167° 49' | S. -45 13' | S.by W. | +15° 12' | -35° 27' | | | | | -69° 25' | 167° 39' | R. -40 39' | S.by W. | +3° 58' | -41° 15' | | | | 28 A.M. | -69° 40' | 167° 14' | T. -35 28' | S.by E.½ E. | +3° 58' | -36° 41' | | | | | -69° 40' | 167° 14' | T. -35 17' | S.by E.½ E. | -4° 12' | -38° 33' | | | | | -69° 40' | 167° 25' | O. -36 51' | S.by E. | -6° 18' | -41° 46' | | | | | -69° 40' | 167° 25' | S. -37 06' | S.½ E. | -6° 18' | -41° 35' | | | | 28 P.M. | -69° 47' | 167° 13' | R. -56 47' | W.N.W. | -4° 12' | -41° 03' | | | | | -69° 36' | 167° 14' | R. -50 21' | N.W.by W. | -2° 05' | -39° 11' | | | * The inclination is computed from the observed declination at West - 152° 46', and at E. by S. - 49° 06'; with the approximate inclination which these give we have $\psi'$ at East - 48° 06'; $\psi = \frac{152° 46' + 48° 06'}{2}$ = - 100° 26'; $\delta$ at East and West 52° 20'; and $\theta = \frac{\sin 52° 20'}{0.0267} = - 88° 04'$. MDCCCXLIII. ## Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|--------------------------|------------|----------------------------------|-----------------------|-----------------|---------| | | | | | | | | | | | | Mar. 1 A.M. | -69° 22' 167° 40' S. | -47° 21' | N.W. | +12° 31' | -34° 50' | | | | | | | -68° 51' 167° 47' R. | -48° 53' | N.W.by W. | +15° 45' | -33° 08' | | | | | | | -68° 56' 167° 49' O. | -33° 25' | S. | 0° 00' | -33° 25' | | | | | | | -68° 56' 167° 49' S. | -33° 40' | S. | -1° 52' | -35° 32' | | | | | | | -68° 56' 167° 49' W. | -35° 23' | S. | -1° 52' | -37° 15' | | | | | | | -68° 55' 167° 46' S. | -36° 27' | S. | -1° 52' | -37° 19' | | | | | | | -68° 55' 167° 46' T. | -31° 54' | S.by E. | -3° 45' | -35° 39' | | | | | | | -68° 55' 167° 49' R. | -30° 30' | S.S.E. | -7° 22' | -37° 52' | | | | | | | -68° 55' 167° 49' T. | -32° 46' | S. | -1° 52' | -34° 38' | | | | | | | -68° 57' 167° 46' R. | -30° 24' | S.by E. | -5° 33' | -35° 57' | | | | | | | -69° 02' 167° 42' R. | -30° 30' | S.E.by S. | -10° 40' | -41° 10' | | | | | | | -69° 03' 167° 41' R. | -56° 02' | W. | +18° 19' | -37° 43' | | | | | | 2 P.M. | -68° 13' 167° 56' R. | -49° 58' | W.by N. | +15° 07' | -34° 51' | | | | | | | -68° 12' 167° 53' T. | -50° 32' | W. | +15° 38' | -34° 54' | | | | | | | -68° 12' 167° 53' W. | -48° 26' | W. | +15° 30' | -32° 56' | | | | | | | -68° 12' 167° 53' T. | -46° 36' | W. | +15° 30' | -31° 06' | | | | | | | -68° 09' 167° 45' R. | -45° 44' | W. | +15° 22' | -30° 22' | | | | | | | -68° 09' 167° 45' T. | -48° 33' | W. | +15° 20' | -33° 13' | | | | | | 3 A.M. | -67° 40' 167° 40' R. | -47° 00' | W.by S. | +14° 52' | -32° 08' | | | | | | | -67° 24' 166° 34' R. | -46° 12' | W.by S. | +15° 15' | -30° 57' | | | | | | | -67° 23' 166° 33' S. | -46° 12' | W.by S. | +9° 23' | -23° 05' | | | | | | 5 P.M. | -65° 30' 167° 34' R. | -32° 28' | S.W.by S. | +7° 00' | -29° 36' | | | | | | | -65° 40' 165° 06' T. | -36° 36' | S.S.W.by S. | +5° 45' | -29° 19' | | | | | | 6 A.M. | -65° 42' 164° 56' T. | -35° 04' | S.S.W. | +7° 00' | -25° 27' | | | | | | | -65° 42' 164° 56' S. | -32° 27' | S.S.W.by S. | +2° 57' | -27° 54' | | | | | | | -65° 42' 164° 56' O. | -30° 51' | S.by W. | +4° 21' | -28° 48' | | | | | | | -65° 42' 164° 56' T. | -33° 09' | S.by W. | +4° 21' | -30° 56' | | | | | | | -65° 44' 165° 05' Y. | -35° 17' | S.by W. | +9° 23' | -29° 18' | | | | | | | -65° 44' 165° 05' S. | -38° 41' | S.W.by S. | +7° 00' | -26° 03' | | | | | | | -65° 44' 165° 05' W. | -33° 03' | S.S.W.by S. | +8° 17' | -29° 22' | | | | | | | -65° 44' 165° 05' W. | -37° 39' | S.W.by S. | +8° 17' | -28° 45' | | | | | | | -65° 50' 164° 41' R. | -35° 55' | S.S.W. | +5° 45' | -30° 10' | | | | | | | -65° 50' 164° 42' R. | -38° 38' | S.W.by S. | +8° 17' | -30° 21' | | | | | | 7 A.M. | -65° 25' 162° 06' Y. | -32° 12' | N.W.by S. | +8° 38' | -23° 34' | | | | | | | -65° 25' 162° 06' T. | -27° 09' | N.W.by S. | +1° 12' | -25° 57' | | | | | | | -65° 25' 162° 06' O. | -30° 52' | N.by W. | +2° 32' | -28° 20' | | | | | | | -65° 25' 162° 06' W. | -30° 37' | N.W.by S. | +6° 22' | -24° 15' | | | | | | | -65° 25' 162° 06' T. | -30° 50' | N.W.N.W. | +5° 09' | -25° 41' | | | | | | 8 P.M. | -64° 37' 163° 07' S. | -14° 56' | E.by N.by S. | -11° 42' | -26° 38' | | | | | | | -64° 37' 163° 07' R. | -15° 13' | E.by N.by S. | -11° 42' | -26° 55' | | | | | | | -64° 32' 163° 59' R. | -34° 46' | S.W.by S. | +7° 39' | -27° 07' | | | | | | | -64° 02' 163° 31' S. | -26° 40' | S.W.by S. | +2° 00' | -24° 40' | | | | | | 9 P.M. | -64° 17' 163° 17' T. | -32° 51' | N.W. | +8° 26' | -24° 25' | | | | | | | -64° 16' 163° 18' T. | -34° 35' | N.W.by S. | +9° 12' | -25° 23' | | | | | | | -64° 16' 163° 18' Y. | -37° 50' | N.W.by W. | +9° 59' | -27° 51' | | | | | | | -64° 16' 163° 18' W. | -35° 16' | N.W.by W. | +9° 59' | -25° 17' | | | | | | | -64° 16' 163° 18' S. | -36° 46' | W.N.W. | +11° 17' | -25° 29' | | | | | | | -64° 16' 163° 19' T. | -36° 10' | W.N.W. | +7° 39' | -24° 59' | | | | | | 10 P.M.| -64° 02' 163° 06' S. | -32° 38' | S.W.by S. | +6° 25' | -25° 39' | | | | | | | -64° 04' 163° 06' O. | -32° 04' | S.S.W.by S. | +7° 39' | -25° 54' | | | | | | | -64° 04' 163° 02' T. | -33° 33' | S.W.by S. | +10° 53' | -25° 29' | | | | | | | -64° 03' 163° 49' S. | -36° 22' | S.W.by S. | +11° 25' | -22° 58' | | | | | | | -64° 03' 162° 45' W. | -34° 23' | S.W.by W. | +2° 42' | -25° 25' | | | | | | 11 A.M.| -63° 57' 161° 11' T. | -28° 07' | S.by W. | +7° 39' | -26° 25' | | | | | | | -63° 58' 161° 15' S. | -34° 04' | S.W.by S. | +7° 39' | -26° 25' | | | | | | | -64° 07' 161° 16' T. | -35° 27' | W.N.W. | +11° 17' | -24° 10' | | | | | ## Observations of Declination. (Continued.) | Date | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------------|----------|----------|----------------------|--------------------------|-------------|----------------------------------|----------------------|-----------------|---------| | Mar. 12 P.M. | | | | | | | | | | | Lat. | Long. | | | | | | | | | | -64° 07' | 161° 16' | W. | -35° 19' | W.N.W. | -83° 00' | +11° 17' | -24° 02' | -24° 06' | | | -64° 07' | 161° 16' | R. | -36° 25' | W.by N.½ N. | | | | | | | -64° 07' | 161° 16' | T. | -36° 17' | W.½ S. | | | | | | | -64° 07' | 161° 16' | T. | -35° 30' | W.by S. | | | | | | | -64° 06' | 161° 10' | R. | -35° 11' | W.by S. | | | | | | | -64° 06' | 161° 05' | R. | -35° 02' | W.by S. | | | | | | | 14 P.M. | | | | | | | | | | | -62° 48' | 157° 14' | R. | -18° 31' | S.E.by S. | | | | | | | -62° 48' | 157° 14' | O. | -21° 04' | S.S.E. | | | | | | | -62° 48' | 157° 14' | S. | -21° 31' | S.S.E. | | | | | | | -62° 50' | 157° 14' | R. | -19° 00' | S.by E.½ E. | -82° 33' | -3° 43' | -22° 43' | -24° 07' | | | -62° 50' | 157° 14' | R. | -12° 11' | S.E.by E. | | | | | | | -62° 50' | 157° 14' | Y. | -23° 23' | S.S.E. | | | | | | | -62° 55' | 157° 02' | W. | -22° 29' | S.by E. | | | | | | | 17 A.M. | | | | | | | | | | | -64° 19' | 153° 40' | T. | -28° 35' | S.W.by S. | -84° 00' | +8° 39' | -19° 56' | | | | -64° 19' | 153° 40' | W. | -29° 15' | S.W.by S. | | | | | | | 18 A.M. | | | | | | | | | | | -63° 54' | 151° 56' | SM. | -6° 11' | E.N.E. | | | | | | | -63° 54' | 151° 52' | S. | -5° 25' | E. | | | | | | | -63° 54' | 151° 52' | O. | -7° 29' | S.E.by E. | -84° 06' | -12° 48' | -20° 17' | -20° 15' | | | -63° 50' | 151° 48' | T. | -7° 33' | S.E.by E. | | | | | | | -63° 50' | 151° 48' | SM. | -7° 15' | S.E.by E. | | | | | | | -63° 50' | 151° 48' | S. | -8° 05' | S.E.by E. | | | | | | | -63° 50' | 151° 48' | O. | -8° 21' | S.E.by E.½ E. | | | | | | | -63° 50' | 151° 48' | R. | -18° 02' | S.by E. | | | | | | | -63° 50' | 151° 48' | T. | -19° 05' | S.by W. | | | | | | | -63° 50' | 151° 48' | S. | -17° 08' | S. | -84° 00' | 0° 00' | -17° 08' | -18° 59' | | | -63° 50' | 151° 48' | R. | -14° 09' | S.S.E. | | | | | | | 18 P.M. | | | | | | | | | | | -63° 51' | 151° 48' | R. | -13° 20' | S.by E.½ E. | | | | | | | 19 A.M. | | | | | | | | | | | -64° 14' | 149° 10' | T. | -27° 16' | S.W.by S. | | | | | | | -64° 16' | 149° 15' | R. | -27° 13' | S.W.by S. | | | | | | | -64° 16' | 149° 15' | W. | -26° 08' | S.W.by S. | | | | | | | -64° 18' | 149° 09' | R. | -25° 43' | S.W.½ S. | | | | | | | 19 P.M. | | | | | | | | | | | -64° 24' | 148° 27' | R. | -26° 04' | S.W.by S. | | | | | | | 20 P.M. | | | | | | | | | | | -65° 04' | 142° 49' | R. | -31° 29' | W. | -85° 25' | +19° 26' | -12° 03' | -12° 37' | | | 21 A.M. | | | | | | | | | | | -64° 26' | 140° 46' | SM. | -24° 11' | N.W.W. | | | | | | | -64° 26' | 140° 46' | Y. | -21° 11' | N.W.W. | | | | | | | -64° 26' | 140° 46' | SM. | -22° 47' | N.W.W. | | | | | | | -64° 26' | 140° 46' | O. | -21° 18' | N.W.by W. | -84° 55' | +14° 00' | -7° 18' | -6° 57' | | | -64° 18' | 140° 27' | S. | -19° 40' | N.W.by W. | | | | | | | 21 P.M. | | | | | | | | | | | -64° 01' | 140° 31' | W. | -23° 56' | N.W.W. | | | | | | | 22 A.M. | | | | | | | | | | | -63° 18' | 140° 04' | S. | -3° 46' | N. | | | | | | | -63° 18' | 140° 04' | O. | -1° 55' | N.½ E. | | | | | | | -63° 18' | 140° 04' | T. | -6° 16' | N.by W. | | | | | | | -63° 18' | 140° 04' | T. | -19° 52' | W.by N.½ N. | | | | | | | -63° 18' | 140° 04' | Y. | -18° 31' | W.N.W. | | | | | | | -63° 20' | 139° 52' | S. | -20° 19' | W.N.W. | | | | | | | -63° 14' | 139° 43' | R. | -19° 39' | N.W.by W.½ W. | | | | | | | -63° 14' | 139° 43' | R. | -22° 28' | W. | | | | | | | -63° 09' | 139° 28' | R. | -21° 01' | W.N.W. | | | | | | | -63° 03' | 139° 38' | R. | -20° 52' | N.W.by W.½ W. | | | | | | | -63° 03' | 139° 38' | R. | -14° 41' | N.W.½ N. | | | | | | | -63° 03' | 139° 38' | R. | -22° 01' | W. | | | | | | | 22 P.M. | | | | | | | | | | | -62° 53' | 139° 06' | R. | -15° 17' | N.W.by W. | | | | | | | -62° 52' | 139° 05' | R. | -14° 43' | N.W.½ W. | | | | | | | -62° 32' | 137° 40' | R. | -20° 26' | W. | -84° 00' | +14° 43' | -5° 43' | -4° 05' | | ## Observations of Declination. (Continued.) | Date | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------------|----------|----------|----------------------|--------------------------|-------------|----------------------------------|-----------------------|-----------------|---------| | **Mar. 22 P.M.** | | | | | | | | | | | | Lat. | Long. | | | | | | | | | -62° 32' | 137° 40' | R. | -16° 55' | W.by N.½ N. | -84° 00' | +13° 46' | -3° 09' | -9° 05' | | | -62° 28' | 137° 26' | R. | -18° 35' | W.by S.½ S. | | | | | | | -62° 28' | 137° 26' | R. | -18° 29' | W.by N. | | | | | | | **23 A.M.** | | | | | | | | | | | -62° 05' | 136° 05' | SM. | -12° 53' | N.W.by N.½ W. | | | | | | | -62° 18' | 136° 25' | T. | -14° 00' | N.W.by W. | | | | | | | -62° 18' | 136° 25' | W. | -13° 48' | N.W.by W. | | | | | | | -62° 20' | 136° 27' | R. | -11° 53' | N.W.by W. | | | | | | | -62° 17' | 136° 29' | R. | -11° 41' | N.W.by W. | | | | | | | -62° 16' | 136° 26' | R. | -9° 59' | N.W.by W. | | | | | | | -62° 13' | 136° 20' | R. | -11° 19' | N.W.by W. | | | | | | | **23 P.M.** | | | | | | | | | | | -62° 07' | 136° 08' | R. | -11° 05' | N.W.by W.½ W. | | | | | | | -62° 07' | 136° 08' | R. | -14° 02' | W.½ S. | | | | | | | -62° 06' | 136° 07' | R. | -11° 00' | S.W.by W. | | | | | | | -62° 06' | 136° 07' | O. | -14° 49' | W.by N. | | | | | | | -62° 06' | 136° 07' | S. | -10° 59' | N.W.by W. | | | | | | | -62° 06' | 136° 06' | T. | -12° 41' | N.W.by W.½ W. | | | | | | | **25 A.M.** | | | | | | | | | | | -60° 30' | 131° 47' | S. | +0° 15' | N.W. | | | | | | | -60° 30' | 131° 47' | O. | +1° 13' | N.W. | | | | | | | -60° 30' | 131° 47' | Y. | +0° 16' | N.W. | | | | | | | -60° 30' | 131° 47' | W. | +0° 50' | N.W. | | | | | | | -60° 30' | 131° 47' | T. | -0° 35' | N.W. | | | | | | | -60° 23' | 131° 28' | R. | -1° 51' | N.W.½ W. | | | | | | | -60° 23' | 131° 28' | R. | -5° 51' | W. | | | | | | | -60° 23' | 131° 28' | T. | -3° 10' | N.W. | | | | | | | -60° 23' | 131° 28' | W. | -1° 51' | N.W. | | | | | | | -60° 22' | 131° 27' | R. | +0° 33' | N.W. | | | | | | | **25 P.M.** | | | | | | | | | | | -60° 20' | 131° 22' | R. | +1° 00' | N.W.by N. | | | | | | | -60° 20' | 131° 22' | T. | +18° 20' | E.N.E. | | | | | | | -60° 20' | 131° 22' | T. | +18° 12' | E.½ S. | | | | | | | -60° 20' | 131° 22' | R. | +14° 06' | N.E.by N. | | | | | | | -60° 20' | 131° 21' | R. | +18° 59' | N.E.by E.½ E. | | | | | | | -60° 20' | 131° 21' | SM. | +19° 01' | E.N.E. | | | | | | | -60° 20' | 131° 21' | R. | +22° 22' | N.W.by N. | | | | | | | -60° 20' | 131° 21' | SM. | +17° 35' | N.E.by E. | | | | | | | -60° 20' | 131° 21' | T. | +18° 36' | N.E.by E. | | | | | | | -60° 20' | 131° 21' | S. | +18° 17' | N.E.by E. | | | | | | | -60° 20' | 131° 21' | W. | +20° 05' | E.½ N. | | | | | | | -60° 20' | 131° 21' | R. | +18° 49' | N.E.by E.½ E. | | | | | | | -60° 20' | 131° 21' | R. | +16° 36' | N.E. | | | | | | | -60° 19' | 131° 21' | R. | +3° 47' | N.W.by N. | | | | | | | -60° 19' | 131° 21' | R. | +8° 33' | N. | | | | | | | **26 A.M.** | | | | | | | | | | | -59° 25' | 130° 14' | R. | +3° 21' | N.W.by N. | | | | | | | -59° 13' | 130° 02' | R. | +7° 01' | N. | | | | | | | -59° 13' | 130° 02' | S. | +4° 42' | N.N.W. | | | | | | | -59° 11' | 130° 00' | R. | +1° 49' | N.N.W. | | | | | | | -59° 10' | 129° 56' | R. | +2° 32' | N.N.W. | | | | | | | -59° 10' | 129° 56' | O. | +1° 48' | N.N.W. | | | | | | | -59° 10' | 129° 56' | W. | +2° 48' | N.N.W. | | | | | | | -59° 03' | 129° 40' | S. | +4° 59' | N.N.W. | | | | | | | **27 A.M.** | | | | | | | | | | | -58° 08' | 128° 46' | R. | +8° 55' | N.N.W. | | | | | | | -58° 08' | 128° 46' | S. | +5° 44' | N.N.W. | | | | | | | -58° 06' | 128° 43' | S. | +6° 53' | N.N.W. | | | | | | | **28 A.M.** | | | | | | | | | | | -57° 24' | 127° 50' | W. | -2° 21' | W.½ S. | | | | | | | -57° 24' | 127° 50' | O. | +0° 05' | W.½ S. | | | | | | ## Observations of Declination. (Continued.) | Date | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------------|----------|----------|----------------------|--------------------------|-------------|----------------------------------|----------------------|-----------------|---------| | Mar. 28 A.M. | | | | | | | | | | | | Lat. | Long. | | | | | | | | | -57° 19' | 127° 49' | R. | -1° 35' | w. by s. | +81° 45' | +10° 40' | +9° 05' | +8° 47' | | | -57° 19' | 127° 49' | T. | -2° 16' | w. ½ s. | | | | | | | -57° 20' | 127° 47' | R. | -2° 56' | w. | | | | | | | -57° 20' | 127° 47' | W. | -1° 20' | w. ½ N. | | | | | | | -57° 20' | 127° 47' | T. | -3° 05' | w. by s. ¼ s. | | | | | | | -57° 21' | 127° 42' | R. | -2° 05' | w. ½ N. | | | | | | | -57° 21' | 127° 42' | S. | -3° 34' | w. ½ N. | | | | | | | -57° 22' | 127° 37' | R. | +0° 39' | w. | | | | | | | 29 P.M. | | | | | | | | | | | -56° 21' | 130° 30' | S. | +9° 40' | N.E. | | | | | | | -56° 21' | 130° 42' | R. | +13° 12' | N.E. | | | | | | | -56° 21' | 130° 42' | S. | +9° 04' | N.E. | | | | | | | -56° 16' | 130° 46' | R. | +13° 24' | N.E. | | | | | | | -56° 14' | 130° 50' | R. | +11° 27' | N.E. | | | | | | | -56° 05' | 130° 42' | T. | +14° 07' | N.E. | | | | | | | -56° 05' | 130° 42' | W. | +13° 50' | N.E. by N. | | | | | | | -56° 08' | 130° 55' | R. | +11° 38' | N.E. | | | | | | | 30 A.M. | | | | | | | | | | | -55° 20' | 131° 39' | SM. | +8° 57' | N.E. ½ E. | | | | | | | -55° 00' | 131° 43' | T. | +6° 27' | N.E. by N. | | | | | | | -55° 00' | 131° 43' | SM. | +5° 43' | N.E. by N. | | | | | | | -55° 16' | 131° 09' | R. | +8° 05' | N.E. by E. | | | | | | | -55° 16' | 131° 09' | R. | +11° 55' | E. | | | | | | | -55° 14' | 131° 12' | R. | +8° 55' | N.E. ½ E. | | | | | | | -55° 14' | 131° 12' | T. | +6° 27' | N.E. ½ N. | | | | | | | -55° 14' | 131° 12' | S. | +4° 16' | N.E. by N. | | | | | | | -55° 14' | 131° 12' | O. | +4° 28' | N.E. ½ N. | | | | | | | -55° 14' | 131° 18' | Y. | +6° 00' | N.E. ½ E. | | | | | | | -55° 14' | 131° 18' | W. | +5° 28' | N.E. by N. | | | | | | | -55° 11' | 131° 15' | R. | +6° 33' | N.E. by N. | | | | | | | -55° 11' | 131° 15' | T. | +6° 04' | N.E. by N. | | | | | | | 30 P.M. | | | | | | | | | | | -55° 05' | 132° 48' | W. | +3° 18' | N.E. ½ N. | | | | | | | -55° 05' | 132° 48' | T. | +4° 16' | N.N.E. | | | | | | | -55° 05' | 132° 48' | S. | -2° 50' | N. | | | | | | | -55° 05' | 132° 48' | T. | +7° 07' | N.E. by N. | | | | | | | -55° 07' | 132° 37' | R. | +8° 14' | N.E. by N. | | | | | | | -55° 04' | 132° 40' | R. | +5° 57' | N.E. by N. | | | | | | | -55° 04' | 132° 40' | Y. | +8° 43' | N.E. by N. | | | | | | | -55° 02' | 132° 42' | R. | +4° 56' | N.E. by N. | | | | | | | 31 A.M. | | | | | | | | | | | -54° 07' | 134° 31' | S. | +4° 23' | N.E. by E. | | | | | | | -54° 07' | 134° 21' | T. | +5° 06' | E.N.E. | | | | | | | -54° 07' | 134° 21' | O. | +5° 52' | N.E. by E. | | | | | | | -54° 01' | 134° 35' | T. | +5° 57' | E. by N. | | | | | | | -54° 01' | 134° 35' | S. | +6° 33' | E. ½ S. | | | | | | | -54° 01' | 134° 35' | S. | +5° 15' | E.by N. ½ N. | | | | | | | -54° 04' | 134° 35' | O. | +3° 27' | E.N.E. | | | | | | | -54° 04' | 134° 40' | W. | +6° 32' | E.N.E. | | | | | | | -54° 05' | 134° 40' | W. | +5° 26' | E. by N. | | | | | | | -54° 04' | 134° 43' | R. | +6° 25' | E.by N. ½ N. | | | | | | | -54° 04' | 134° 47' | R. | +6° 30' | E.by N. ½ N. | | | | | | | -54° 04' | 134° 54' | R. | +7° 04' | E. ½ N. | | | | | | | April 1 P.M.| | | | | | | | | | | -52° 56' | 135° 23' | R. | +1° 49' | N.N.E. | | | | | | | -52° 55' | 135° 24' | R. | +1° 49' | N.N.E. | | | | | | *Very much motion; observations uncertain to two or three degrees.* ### Observations of Declination. (Continued.) | 1841 | Position | Initials | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Mean Declination | Remarks | |------|----------|----------|----------------------|---------------------------|-------------|---------------------------------|-----------------------|------------------|---------| | | Lat. | Long. | | | | | | | | | April 1 P.M. | -52° 55' 135° 24' S. | + 1° 34' N.N.E. | -78° 50' | - 2° 42' | - 1° 08' | - 1° 03' | | | -52° 51' 135° 26' T. | + 0° 30' N.N.E. | - 2° 42' | - 2° 12' | | | -52° 49' 135° 29' T. | + 3° 13' N.N.E. | - 2° 42' | + 0° 31' | | | -52° 49' 135° 29' R. | + 2° 24' N.N.E. | - 2° 42' | - 0° 18' | | | -52° 46' 135° 29' R. | + 1° 10' N.N.E. | - 2° 42' | - 1° 32' | | 2 A.M. | -51° 12' 136° 50' T. | - 1° 37' N.E. by N. | - 3° 30' | - 5° 07' | | | -51° 12' 136° 55' R. | - 1° 00' N.N.E. | - 2° 28' | - 3° 28' | | | -51° 12' 136° 55' S. | - 5° 26' N. | - 77° 40' | 0° 00' | - 5° 26' | - 4° 39' | | | -51° 06' 136° 52' T. | - 7° 08' N. by W. | + 1° 12' | - 5° 56' | | | -51° 07' 136° 59' R. | - 0° 49' N.N.E. | - 2° 28' | - 3° 17' | | 5 P.M. | -44° 52' 143° 30' S. | - 0° 06' N.E. by E. | - 3° 51' | - 3° 57' | | | -44° 52' 143° 28' R. | - 1° 11' N.E. by E. | - 3° 51' | - 5° 02' | | | -44° 51' 143° 34' R. | - 5° 41' S.E. by S. | - 3° 17' | - 8° 58' | | 6 A.M. | -44° 09' 145° 33' T. | - 6° 33' E. | - 4° 38' | -11° 11' | | | -44° 09' 145° 35' R. | - 5° 35' N.E.by E.½ E. | - 3° 42' | - 9° 17' | - 8° 46' | | | -44° 06' 145° 42' R. | - 7° 01' N.E. by E. | - 3° 26' | -10° 27' | | | -44° 05' 145° 43' T. | - 7° 19' N.E. by E. | - 3° 26' | -10° 45' | | | -44° 01' 145° 53' T. | - 6° 50' N.E. by E. | - 3° 26' | -10° 16' | | 6 P.M. | -43° 40' 146° 40' R. | - 5° 58' N.E.½ E. | - 3° 08' | - 9° 06' | Observations of the Inclination in H.M.S. Erebus, from September 1840 to April 1841, made with Needle R. F. 4. Observers Captain Ross and Lieutenant Smith, R.N. | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|--------------|-----------------------------------|------------------------|-----------------|---------| | 1840 | Magnetic Observatory, Van Diemen Island. | h m | Direct. | -71 06·8 | | | | | | | Sept. 17. | -42° 52' 14" 7' 24" | 2 P.M. | S. at 20°. | -71 13·4 | | | | | | | | | | N. at 20°. | -71 12·1 | | | | | | | | | | S. | -71 15·1 | | | | | | | | | 11 A.M. | Direct. | -71 02·8 | | | | | | | | | 2 P.M. | Direct. | -71 05·7 | | | | | | | | | 3 P.M. | Direct. | -70 58·4 | | | | | | | | | 1 P.M. | Direct. | -71 05·2 | | | | | | | | | | S. at 20°. | -71 09·9 | | | | | | | | | | S. at 20°. | -71 07·2 | | | | | | | | | | N. at 20°. | -70 58·5 | | | | | | | | | | Direct. | -71 02·6 | | | | | | | Oct. 17. | At anchor. | 1 30 P.M. | Direct. | -70 39·1 | | | | | | | | | | S. | -70 42·8 | | | | | | | | | | Direct. | -71 46·7 | | | | | | | | | | S. | -71 48·5 | | | | | | | | | 2 P.M. | Direct. | -70 29·9 | | | | | | | | | | S. | -70 33·4 | | | | | | | | | | Direct. | -70 35·6 | | | | | | | | | | S. | -70 44·1 | | | | | | | | | 2 30 P.M. | Direct. | -71 00·5 | | | | | | | | | | S. | -70 49·6 | | | | | | | | | 1 45 P.M. | Direct. | -72 06·7 | | | | | | | | | | Direct. | -72 12·6 | | | | | | | | | 6 A.M. | Direct. | -72 20·9 | | | | | | | | | | S. | -72 18·7 | | | | | | | | | | Direct. | -72 12·5 | | | | | | | | | | S. | -72 07·8 | | | | | | | | | | Direct. | -72 10·3 | | | | | | | | | | S. | -71 54·8 | | | | | | | | | | Direct. | -72 01·6 | | | | | | | | | | S. | -71 59·6 | | | | | | | | | | Direct. | -71 22·5 | | | | | | | | | | S. | -71 30·0 | | | | | | | | | | Direct. | -72 17·0 | | | | | | | | | | S. | -72 29·4 | | | | | | | | | | Direct. | -72 37·8 | | | | | | | | | | S. | -72 24·3 | | | | | | | | | | Direct. | -71 21·0 | | | | | | | | | | S. | -71 24·5 | | | | | | | | | | Direct. | -71 38·0 | | | | | | | | | | S. | -71 44·7 | | | | | | | | | | Direct. | -71 57·7 | | | | | | | | | | S. | -71 34·9 | | | | | | | | | | Direct. | -70 52·0 | | | | | | | | | | S. | -70 43·7 | | | | | | | | | | Direct. | -70 38·5 | | | | | | | | | | S. | -70 32·3 | | | | | | | | | | Direct. | -70 16·9 | | | | | | | | | | S. | -70 17·0 | | | | | | | | | | Direct. | -70 16·7 | | | | | | | | | | S. | -70 16·2 | | | | | | Observed on shore. -71 06 -70 38 S.E. by s. -43 -71 24 W. +24 -71 24 S. by E. -61 -71 33 S.S.E. -53 -71 33 S.E. -32 -71 27 W.N.W. +46 -71 24 N. +74 -71 06 N.N.E. +70 -71 00 N.E. +64 -70 58 E.N.E. +46 -71 15 E. +24 -71 02 N.N.W. +71 -71 12 W.S.W. -3 -71 26 W.N.W. +46 -71 00 S.W. -32 -71 20 S.S.W. -52 -71 27 S. -61 -71 18 S.S.E. -53 -71 09 ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination, Face east. | Ship's head | Correction for ship's attraction. | Mean Inclination, Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|-------------|-----------------------------------|------------------------|-----------------|---------| | 1840 | | | | | | | | | | | Oct. 29. | At anchor. | h m 6 A.M. | Direct. S. | -70° 46'5" | S.E. | -31 | -71° 17' | -70° 45" | | | Nov. 13. | -44° 16'149" 29 | 1 15 P.M. to 2 15 P.M. | Direct. S. | -71° 03'1" | E.S.E. | -3 | -71° 09' | -70° 41" | | | | -45° 13'151" 57 | 10 40 A.M. to 11 25 A.M. | Direct. S. | -71° 42'7" | S.E. | -33 | -72° 17' | -71° 49" | | | | -45° 33'152" 45 | 11 20 A.M. to Noon. | Direct. S. | -72° 26'0" | E. | +23 | -72° 05' | -71° 37" | | | | -46° 18'154" 30 | 1 30 P.M. to 2 20 P.M. | Direct. S. | -72° 21'2" | E.S.E. | -5 | -72° 32' | -72° 04" | | | | -47° 46'157" 40 | 10 45 A.M. to 11 45 A.M. | Direct. S. | -73° 20'2" | S.E.by E.½E. | -14 | -73° 42' | -73° 14" | | | | -49° 20'160" 13 | 11 15 A.M. to Noon. | Direct. S. | -74° 22'7" | S.E.by E.½E. | -15 | -74° 43' | -74° 15" | | | | -50° 28'164" 9 | 11 20 A.M. to Noon. | Direct. S. | -75° 16'8" | E. | +22 | -74° 51' | -74° 23" | | | | Auckland Island. | 1 15 P.M. to 4 P.M. | Direct. S. | -74° 25'5" | W.N.W. | +47 | -73° 49' | -73° 21" | | | | -50° 33'166" 19 | 11 30 A.M. to 0 30 P.M. | Direct. S. | -75° 05'1" | N.W.by w. | +59 | -73° 35' | -73° 07" | | | | At the Magnetic Observatory. | 2 00 P.M. to 5 30 P.M. | Direct. S. | -73° 40'8" | Observed on shore. | -73° 41'3" | -73° 13'3" | | | | Pig Island. | 9 00 A.M. to 10 00 A.M. | Direct. S. | -73° 38'4" | Observed on shore. | -73° 36'3" | -73° 08'3" | | | | -50° 32'166" 12 | 1 30 P.M. to 2 30 P.M. | Direct. S. | -77° 27'5" | Observed on shore. | -77° 31' | -77° 03" | | | | Shoe Island. | 200 yards west of the preceding station. | Direct. | -74° 10'6" | Observed on shore. | -74° 11' | -73° 43" | | *Mean of results whose poles were reversed.* ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east | Ship's head | Correction for ship's attraction. | Mean Inclination. Face east | True Inclination. | Remarks | |------|----------|-------------|-----------------|-------------------------------|------------|----------------------------------|------------------------|------------------|---------| | 1840 | Nov. 26. | At anchor. | h m | Direct. | s.s.w. | -58 | -73 43 | -73 15 | | | | | | 6 00 to 6 40 P.M. | -72 42-8 | | | | | | | | | | 6 45 P.M. | Direct. | w.s.w. | -6 | -73 43 | -73 15 | | | | | | | S. | | | | | | | | | | | -72 48-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 40-4 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 34-7 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 29-1 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 26-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 58-2 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 50-4 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 56-6 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 53-2 | | | | | | | | | | | Direct. | | | | | | | | | | | N. | | | | | | | | | | | -73 51-9 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -65 39-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -65 28-0 | | | | | | | | | | | Direct. | | | | | | | | | | | N. | | | | | | | | | | | -65 13-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -65 38-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 03-4 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 04-7 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 46-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 44-6 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 12-2 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 13-6 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 30-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 25-1 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 33-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -72 32-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 10-2 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 01-8 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 27-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 32-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 58-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 49-8 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 10-6 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 12-8 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 39-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 42-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 33-2 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 41-1 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 51-0 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 53-3 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -75 01-5 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -75 02-3 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -74 39-2 | | | | | | | | | | | Direct. | | | | | | | | | | | S. | | | | | | | | | | | -73 10-7 | | | | | | | | | | | Direct. | | | | | | | | | | | E. by N. | | | | | | | | | | | +36 | | | | | | | | | | | Direct. | | | | | | | | | | | E. | | | | | | | | | | | +22 | | | | | | | | | | | Direct. | | | | | | | | | | | N.E. | | | | | | | | | | | +66 | | | | | | | | | | | Direct. | | | | | | | | | | | N.E. by E. | | | | | | | | | | | +59 | | | | | | | | | | | Direct. | | | | | | | | | | | E.N.E. | | | | | | | | | | | +47 | | | | | | | | | | | Direct. | | | | | | | | | | | E. by s. | | | | | | | | | | | +7 | | | | | | | | | | | Direct. | | | | | | | | | | | E.S.E. | | | | | | | | | | | -7 | | | | | | | | | | | Direct. | | | | | | | | | | | S.E. by E. | | | | | | | | | | | -22 | | | | | | MDCCCXLIII. ## Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|-------------|-----------------------------------|------------------------|----------------|---------| | 1840 | Campbell Island | h m | Direct. S. | -75° 42' 8" | n.w. | +67 | -74° 38' | -74° 10' | | | | | 10 00 A.M. | Direct. S. | -75° 48' 3" | | | | | | | | | 11 00 A.M. | Direct. S. | -74° 53' 7" | w. | +22 | -74° 36' | -74° 08' | | | | | 1 00 P.M. | Direct. S. | -73° 18' 4" | s.s.w. | -60 | -74° 16' | -73° 48' | | | | | | | -73° 13' 1" | | | | | | | | | 2 00 P.M. | Direct. S. | -73° 44' 5" | | | | | | | | | to | Direct. N. | -74° 29' 7" | | | | | | | | | 4 15 P.M. | Direct. S. | -74° 27' 8" | | | | | | | | | | Direct. S. | -74° 30' 2" | | | | | | | | | 6 15 A.M. | Direct. S. | -74° 24' 5" | | | | | | | | | to | Direct. N. | -74° 24' 4" | | | | | | | | | 8 30 A.M. | Direct. S. | -74° 18' 5" | | | | | | | | | | | -74° 23' 1" | | | | | | | | | 1 00 P.M. | Direct. S. | -73° 18' 4" | s.s.w. | -60 | -74° 16' | -73° 48' | | | | | | | -73° 13' 1" | | | | | | | | | 9 30 A.M. | Direct. S. | -73° 42' 1" | e. by s. | +7 | -73° 35' | -73° 07' | | | | | | Direct. N. | -73° 16' 0" | | -69 | -74° 25' | -73° 57' | | | | | 4 30 A.M. | Direct. S. | -74° 21' 0" | s.s.e. | -61 | -75° 28' | -74° 46' | | | | | | | -74° 33' 8" | | | | | | | | | 5 00 P.M. | Direct. N. | -73° 39' 9" | s.s.e., ½ E. | -57 | -75° 00' | | | | | | | | -74° 27' 0" | | | | | | | | | 10 15 A.M. | Direct. N. | -75° 26' 1" | s. by w. | -71 | -76° 44' | -76° 16' | | | | | to | Direct. S. | -75° 40' 5" | | | | | | | | | 11 10 A.M. | Direct. S. | -75° 32' 5" | | | | | | | | | 4 20 A.M. | Direct. N. | -77° 14' 0" | s.s.e. | -67 | -78° 11' | -77° 43' | | | | | | | -77° 01' 2" | | | | | | | | | | | -76° 58' 0" | | | | | | | | | 5 10 P.M. | Direct. N. | -77° 15' 0" | s. by e. | -74 | -78° 19' | -77° 51' | | | | | to | Direct. N.S.| -77° 00' 5" | | | | | | | | | 5 50 P.M. | Direct. N.S.| -77° 00' 1" | | | | | | | | | 10 15 A.M. | Direct. S. | -77° 24' 2" | s. | -77 | -78° 32' | -78° 04' | | | | | to | Direct. N. | -77° 19' 0" | | | | | | | | | 11 10 A.M. | Direct. N.S.| -77° 10' 8" | | | | | | | | | | | -77° 05' 2" | | | | | | | | | 10 15 A.M. | Direct. S. | -78° 05' 0" | s.s.w. | -69 | -79° 14' | -79° 17' | | | | | to | Direct. S. | -78° 08' 5" | | | | | | | | | 11 20 A.M. | Direct. N.S.| -78° 06' 7" | | | | | | | | | | | -77° 59' 0" | | | | | | | | | 6 40 P.M. | Direct. N.S.| -78° 57' 8" | e. | +20 | -78° 38' | -78° 39' | | | | | | | -78° 59' 0" | | | | | | | | | 5 00 A.M. | Direct. N. | -78° 27' 3" | s.e., ½ s. | -52 | -79° 19' | -79° 05' | | | | | to | Direct. N.S.| -78° 13' 4" | | | | | | | | | 6 00 A.M. | Direct. N.S.| -78° 24' 0" | | | | | | | | | | | -78° 05' 5" | | | | | | | | | 11 00 A.M. | Direct. S. | -78° 47' 2" | s.s.e. | -70 | -79° 57' | -79° 24' | | | | | to | Direct. N. | -78° 13' 6" | | | | | | | | | Noon. | Direct. N.S.| -78° 01' 0" | | | | | | *Mean on shore 75° 55', Mean on board 75° 50'.* ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|-------------|-----------------------------------|------------------------|-----------------|---------| | 1840 | | | | | | | | | | | Dec.24. | -60° 46' 170" 44' | h m 5 15 P.M. to 6 10 P.M. | Direct. | -78° 40'·4 | s.e. by s. | -59 | -79° 34' | -79° 06' | | | | | | S. | -78° 37'·5 | N. | -78° 45'·8 | -78° 16'·3 | | | | | | | N.S. | -78° 43'·4 | s. | -79 | -79° 58' | -79° 30' | | | | | | | -78° 40'·1 | N.S. | -78° 32'·9 | | | | | | | | Noon. | -81° 29'·2 | N. | +88 | -80° 01' | -79° 57' | -79° 41' | | | | | | -81° 25'·0 | N.S. | -79° 59' | -80° 39' | | | | | | | | -81° 27'·2 | s.s.w. | -71 | -80° 26' | -79° 58' | | | | | | | -79° 28'·3 | | | | | | | | | | 10 30 A.M. | -80° 53'·3 | W. ½ N. | +27 | -80° 26' | -79° 58' | | | | | | | -79° 26'·4 | S. | | | | | | | | | | -79° 21'·4 | N. | -80 | -80° 37' | -80° 09' | | | | | | | -79° 18'·4 | N.S. | | | | | | | | | | -78° 32'·7 | s. | -80 | -80° 37' | -80° 09' | | | | | | | -79° 37'·2 | N.S. | | | | | | | | | | -79° 22'·8 | | | | | | | | | | 8 40 A.M. | -80° 25'·0 | S.S.W. ½ W. | -67 | -81° 31' | -81° 03' | | | | | | | -80° 24'·1 | | | | | | | | | | | -80° 28'·2 | | | | | | | | | | | -80° 18'·8 | | | | | | | | | | 10 30 A.M. | -80° 28'·1 | S.S.W. | -73 | -81° 41' | -81° 30' | -81° 03' | | | | | | -80° 16'·8 | | | | | | | | | | | -80° 20'·5 | | | | | | | | | | | -79° 47'·8 | S.by w. | -80 | -81° 08' | -81° 37' | | | | | | | -80° 17'·3 | | | | | | | | | | 6 45 A.M. | -80° 23'·9 | S.W. by s. | -61 | -81° 25' | -81° 17' | -81° 11' | | | | | | -80° 16'·2 | | | | | | | | | | | -80° 16'·3 | | | | | | | | | | | -80° 14'·4 | | | | | | | | | | | -80° 17'·9 | | | | | | | | | | | -80° 54'·3 | | | | | | | | | | 10 45 A.M. | -81° 23'·8 | S. | -84 | -82° 48' | -82° 50' | -82° 20' | | | | | | -81° 25'·6 | N. | | | | | | | | | | -81° 29'·3 | N.S. | | | | | | | | | | -81° 18'·2 | s. | | | | | | | | | | -81° 25'·0 | S.by w. ½ W.| -77 | -82° 42' | -82° 41' | -82° 25' | | | | | | -81° 23'·9 | | | | | | | | | | | -81° 34'·7 | | | | | | | | | | | -81° 49'·4 | | | | | | | | | | 10 00 A.M. | -81° 36'·4 | S. | -85 | -83° 08' | -82° 40' | | | | | | | -81° 39'·0 | N. | | | | | | | | | | -81° 49'·6 | N.S. | | | | | | | | | | -81° 49'·2 | | | | | | --- 2 d 2 ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east | Ship's head | Correction for ship's attraction | Mean Inclination. Face east | True Inclination | Remarks | |------|----------|-------------|-----------------|-------------------------------|------------|---------------------------------|------------------------|----------------|---------| | 1841 | | | | | | | | | | | | Lat. | Long. | h m | Direct. | | | | | | | Jan. 1. | -66 32' | 169 45" | 11 25 A.M. | S. | -84 14'6" | | | | | | | | | to | N. | -84 31'7" | | | | | | | | | 0 30 P.M. | N.S. | -84 41'1" | | | | | | | | | | | -84 32'9" | | | | | | 2. | -66 23' | 170 12" | 10 40 A.M. | Direct. | -84 16'3" | | | | | | | | | to | S. | -85 01'6" | | | | | | | | | 11 45 A.M. | N. | -85 05'6" | | | | | | | | | | N.S. | -84 29'6" | | | | | | 3. | -65 39' | 170 44" | 11 00 A.M. | Direct. | -83 28'7" | | | | | | | | | to | S. | -83 46'0" | | | | | | | | | Noon. | N. | -83 58'0" | | | | | | | | | | N.S. | -83 46'5" | | | | | | 4. | -65 22' | 172 40" | 10 15 A.M. | Direct. | -82 18'3" | | | | | | | | | to | S. | -82 06'0" | | | | | | | | | 11 40 A.M. | N. | -82 19'0" | | | | | | | | | | N.S. | -82 39'1" | | | | | | 5. | -66 55' | 174 31" | 10 30 A.M. | Direct. | -82 03'7" | | | | | | | | | | Direct. | -82 19'9" | | | | | | | | | | Direct. | -82 06'1" | | | | | | | | | | | S.E. by E. | | | | | | | | | | | E.S.E. | | | | | | | | | | | S.E. ½ E. | | | | | | 6. | -67 27' | 174 51" | 7 10 P.M. | Direct. | -83 03'6" | | | | | | | | | to | S. | -83 11'3" | | | | | | | | | 7 50 P.M. | N. | -83 09'2" | | | | | | | | | | N.S. | -83 15'5" | | | | | | 7. | -68 17' | 175 0" | 11 00 A.M. | Direct. | -83 40'0" | | | | | | | | | | S. | -83 35'0" | | | | | | | | | | Direct. | -82 23'1" | | | | | | | | | | Direct. | -82 35'4" | | | | | | | | | | Direct. | -82 26'1" | | | | | | | | | | | E.S.E. | | | | | | | | | | | E.S.E. | | | | | | | | | | | S.E. by S. | | | | | | | | | | | S.E. | | | | | | | | | | | S.S.E. | | | | | | 8. | -68 28' | 176 31" | 11 00 A.M. | Direct. | -84 04'4" | | | | | | | | | to | S. | -84 10'3" | | | | | | | | | 10 15 A.M. | N. | -84 19'6" | | | | | | | | | | Direct. | -84 10'8" | | | | | | | | | | S. | -84 18'1" | | | | | | | | | | N. | -84 22'3" | | | | | | | | | | | E. | | | | | | | | | | | +18 | | | | | | | | | | | -83 53 | | | | | | | | | | | -83 28 | | | | | | On ice.| -68 28' | 176 32" | 1 20 P.M. | Direct. | -83 35'2" | | | | | | | | | to | S. | -83 57'7" | | | | | | | | | 2 00 P.M. | N. | -84 03'5" | | | | | | | | | | N.S. | -84 03'2" | | | | | | | | | | Direct. | -83 43'2" | | | | | | | | | | | W. by s. ½ s. | | | | | | | | | | | -8 8 | | | | | | | | | | | -83 43 | | | | | | | | | | | -84 06 | | | | | | | | | | | -83 46 | | | | | | | | | | | -83 17 | | | | | | | | | | | -83 45 | | | | | | | | | | | -83 25 | | | | | | | | | | | +18 | | | | | | | | | | | -83 59 | | | | | | | | | | | -83 25 | | | | | | | | | | | -83 43 | | | | | | | | | | | -84 06 | | | | | | | | | | | -83 46 | | | | | | | | | | | -83 17 | | | | | | | | | | | -83 45 | | | | | | | | | | | -83 25 | | | | | | | | | | | -84 02'9" | | | | | | | | | | | -83 34'9" | | | | | * The accordance of the results on the 1st of January with the ship's head on the north and south points, is extremely satisfactory with reference to the corrections, which on those points are very large and have opposite signs. ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east | Ship's head | Correction for ship's attraction | Mean Inclination. Face east | True Inclination | Remarks | |------|----------|-------------|-----------------|--------------------------------|------------|---------------------------------|------------------------|----------------|---------| | 1841 | | | | | | | | | | | | Lat. | Long. | h m | Direct. | | | | | | | Jan. 9 | -68° 48' 17" 25" | 2 45 A.M. | -82° 41' 8" | S.S.E. | -76 | -84° 08' | -83° 40' | | | | | | to 4 00 A.M.| -82° 41' 4" | N.S. | | | | | | | | | | -82° 48' 6" | Direct. | | | | | | | | | | -82° 57' 0" | | | | | | | | | | | -83° 09' 4" | | | | | | | | | | 11 40 A.M. | Direct. | | | | | | | | | | | -84° 01' 8" | | | | | | | | | | | -83° 51' 4" | | | | | | | | | | | -84° 16' 2" | | | | | | | | | | | -83° 52' 5" | | | | | | | | | | 10 35 A.M. | Direct. | | | | | | | | | | | -84° 48' 4" | | | | | | | | | | | -84° 48' 5" | | | | | | | | | | | -84° 49' 3" | | | | | | | | | | | -84° 49' 3" | | | | | | | | | | 9 30 A.M. | Direct. | | | | | | | | | | | -84° 55' 4" | | | | | | | | | | | -84° 56' 9" | | | | | | | | | | | -84° 56' 2" | | | | | | | | | | | -84° 51' 4" | | | | | | | | | | 11 00 A.M. | Direct. | | | | | | | | | | | -86° 17' 8" | | | | | | | | | | | -86° 29' 5" | | | | | | | | | | | -86° 25' 2" | | | | | | | | | | 4 40 P.M. | Direct. | | | | | | | | | | | -84° 55' 4" | | | | | | | | | | | -84° 56' 9" | | | | | | | | | | | -84° 56' 2" | | | | | | | | | | | -84° 51' 4" | | | | | | | | | | 5 50 P.M. | Direct. | | | | | | | | | | | -86° 17' 8" | | | | | | | | | | | -86° 29' 5" | | | | | | | | | | | -86° 25' 2" | | | | | | | | | | 10 46 A.M. | Direct. | | | | | | | | | | | -86° 17' 8" | | | | | | | | | | | -86° 29' 5" | | | | | | | | | | | -86° 25' 2" | | | | | | | | | | 11 40 A.M. | Direct. | | | | | | | | | | | -87° 14' 7" | | | | | | | | | | | -87° 44' 5" | | | | | | | | | | | -87° 32' 6" | | | | | | | | | | | -87° 17' 6" | | | | | | | | | | 10 15 A.M. | Direct. | | | | | | | | | | | -87° 04' 5" | | | | | | | | | | | -87° 03' 8" | | | | | | | | | | 9 00 A.M. | Direct. | | | | | | | | | | | -86° 43' 2" | | | | | | | | | | | -87° 10' 4" | | | | | | | | | | | -86° 43' 7" | | | | | | | | | | | -86° 26' 2" | | | | | | | | | | 11 00 A.M. | Direct. | | | | | | | | | | | -86° 43' 2" | | | | | | | | | | | -87° 10' 4" | | | | | | | | | | | -86° 43' 7" | | | | | | | | | | | -86° 26' 2" | | | | | | | | | | Noon. | Direct. | | | | | | | | | | | -86° 43' 2" | | | | | | | | | | | -87° 10' 4" | | | | | | | | | | | -86° 43' 7" | | | | | | | | | | | -86° 26' 2" | | | | | | | | | | 9 15 A.M. | Direct. | | | | | | | | | | | -85° 48' 2" | | | | | | | | | | | -85° 40' 3" | | | | | | | | | | | -85° 48' 5" | | | | | | | | | | | -85° 32' 2" | | | | | | | | | | 11 00 A.M. | Direct. | | | | | | | | | | | -85° 48' 2" | | | | | | | | | | | -85° 40' 3" | | | | | | | | | | | -85° 48' 5" | | | | | | | | | | | -85° 32' 2" | | | | | | | | | | Direct. | -86° 53' 3" | | | | | | | | | | | -86° 50' 2" | | | | | | | | | | | -87° 01' 0" | | | | | | | | | | 7 30 A.M. | Direct. | | | | | | | | | | | -86° 03' 5" | | | | | | | | | | | -86° 32' 2" | | | | | | | | | | | -86° 32' 3" | | | | | | | | | | | -86° 04' 0" | | | | | | | | | | | -86° 22' 9" | | | | | | | | | | 11 00 A.M. | Direct. | | | | | | | | | | | -86° 12' 4" | | | | | | | | | | | -86° 21' 8" | | | | | | | | | | | -86° 22' 2" | | | | | | | | | | | -87° 07' 0" | | | | | | | | | | 10 00 A.M. | Direct. | | | | | | | | | | | -86° 12' 4" | | | | | | | | | | | -86° 21' 8" | | | | | | | | | | | -86° 22' 2" | | | | | | | | | | | -87° 07' 0" | | | | | | | ## Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination Face east | Ship's head | Correction for ship's attraction | Mean Inclination Face east | True Inclination | Remarks | |------|----------|-------------|-----------------|-------------------------------|------------|---------------------------------|------------------------|----------------|---------| | 1841 | | | | | | | | | | | | Lat. | Long. | h m | Direct. | | | | | | | Jan. 19 | -72°31' | 173°39' | 4 30 p.m. to 5 30 p.m. | S. -85°58'4" | s. by E. ½ E. -83° | -87°19 | -86°51 | | | | | | | | N. -85°55'5" | N.S. -85°45'8" | | | | | | 20. | -73°47' | 171°50' | 10 00 a.m. to 11 15 a.m. | Direct. | S. -86°56'7" | s.e. -51° | -87°48 | -87°04 | | | | | | | N. -86°59'8" | N.S. -86°58'4" | | | | | | | | | | N.S. -86°59'1" | | | | | | | | | | Direct. | S.W. -86°49'0" | s.w. by w. -34° | -87°39 | -87°06 | | | | | | | Direct. | E. by N. -87°45'0" | +39° | -87°06 | | | 21. | -74°10' | 170°28' | 0 30 a.m. to 1 30 a.m. | Direct. | S. -86°39'6" | s. by e. -87° | -88°07 | | | | | | | | N. -86°37'4" | N.S. -86°38'5" | | | | | | | | | | N.S. -86°30'5" | | | | | | | | | | Direct. | E. -87°48'1" | N.E. by E. +66° | -87°24 | -87°12 | | | | | | | Direct. | N.E. by N. -88°04'7" | +85° | -87°21 | | | | | | | Direct. | N.N.E. -88°46'3" | +90° | -87°21 | | | | | | | Direct. | N.N.E. -88°51'2" | | | | | | | | | | Direct. | S. -88°40'4" | N. by E. +91° | -87°22 | | | | | | | | N. -88°57'1" | N.S. -88°57'5" | | | | | | | | | | N.S. -88°58'2" | | | | | | | | | | Direct. | S. -86°26'1" | s. by e. -87° | -87°56 | | | | | | | | N. -86°32'3" | N.S. -86°34'2" | | | | | | | | | | N.S. -86°21'7" | | | | | | 22. | -73°56' | 170°51' | 3 10 p.m. to 4 20 p.m. | Direct. | S. -88°40'4" | N. by E. +91° | -87°22 | | | | | | | | N. -88°57'1" | N.S. -88°57'5" | | | | | | | | | | N.S. -88°58'2" | | | | | | | | | | Direct. | S. -86°26'1" | s. by e. -87° | -87°56 | | | | | | | | N. -86°32'3" | N.S. -86°34'2" | | | | | | | | | | N.S. -86°21'7" | | | | | | | | | | Direct. | S. -86°59'0" | E. by s. +6° | -86°53 | | | | | | | | N. -86°36'8" | N.S. -86°23'0" | | | | | | | | | | N.S. -86°35'2" | | | | | | | | | | Direct. | S. -86°49'9" | S. ½ W. -88° | -88°16 | | | | | | | | N. -86°41'4" | N.S. -86°54'3" | | | | | | | | | | Direct. | S. -86°39'7" | S. ½ W. -88° | -88°08 | | | | | | | | N. -88°12'4" | N.S. -88°21'0" | | | | | | | | | | N.S. -88°17'0" | | | | | | | | | | Direct. | S. -88°05'0" | E. +24° | -87°57 | | | | | | | | N. -88°47'7" | N.S. -88°35'7" | | | | | | | | | | N.S. -88°21'0" | | | | | | | | | | Direct. | S. -88°17'0" | E. +24° | -87°57 | | | | | | | | N. -88°05'0" | N.S. -88°47'7" | | | | | | | | | | Direct. | S. -87°24'7" | S.W. by s. -68° | -88°44 | | | | | | | | N. -87°35'7" | N.S. -87°34'0" | | | | | | | | | | N.S. -87°49'2" | | | | | | | | | | Direct. | S. -87°34'7" | S. ½ E. -89° | -89°04 | | | | | | | | N. -87°46'4" | N.S. -88°37'3" | | | | | | | | | | N.S. -87°45'2" | | | | | | | | | | Direct. | S. -87°45'2" | S.S.E. -84° | -89°04 | | | | | | | | N. -87°45'6" | N.S. -87°23'3" | | | | | ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|--------------|-----------------------------------|------------------------|----------------|---------| | 1841 | | | | | | | | | | | | Lat. | Long. | h m | Direct. | | | | | | | Jan. 27 | -76° 06' 168" 11' | 4 20 p.m. to 5 20 p.m. | S. | -88° 05' 4" | S.E. | -52 | -88° 55' | -88° 27' | | | | | | N. | -88° 06' 1" | N.W. by N. | +85 | -88° 05' | -88° 00' | | | | | | N.S. | -87° 59' 0" | N.by W. | +91 | -87° 16' | -86° 48' | | | 28. | -76° 46' 169" 22' | 11 15 a.m. | Direct. | -88° 39' 6" | E.S.E. | -12 | -88° 52' | -88° 00' | | | | -77° 29' 170" 30' | 7 00 p.m. | Direct. | -89° 32' 4" | N.W. by N. | +85 | -88° 05' | -88° 00' | | | 29. | -77° 47' 175" 43' | 6 00 a.m. | Direct. | -88° 44' 7" | N.by W. | +91 | -87° 16' | -86° 48' | | | | | | S. | -88° 54' 6" | N.N.W. | +88 | -86° 23' | -85° 54' | Mech motion. | | | | | N. | -88° 50' 2" | N.W.by N. | +83 | -86° 21' | -85° 54' | | | | | | N.S. | -88° 36' 7" | S.by E. | -82 | -86° 51' | -86° 12' | | | 30. | -77° 47' 180" 28' | 3 10 a.m. | Direct. | -87° 51' 4" | N.N.W. | +88 | -86° 23' | -85° 54' | | | | -77° 35' 181" 20' | Noon. | Direct. | -87° 43' 9" | N.W.by N. | +83 | -86° 21' | -85° 54' | | | 31. | -77° 04' 188" 18' | 9 30 a.m. | Direct. | -87° 30' 3" | N.E.by N. | +83 | -86° 07' | -85° 56' | | | | -77° 06' 189" 06' | 11 30 a.m. | S. | -87° 36' 4" | N.E.by N. | +83 | -86° 07' | -85° 56' | | | | -77° 12' 190" 54' | 7 00 p.m. | Direct. | -87° 26' 0" | N.E.by N. | +83 | -86° 07' | -85° 56' | | | Feb. 1 | -77° 04' 188" 30' | 10 30 a.m. | Direct. | -85° 45' 9" | S.E. | -51 | -86° 37' | -86° 12' | | | | -77° 11' 189" 01' | 7 45 a.m. | Direct. | -85° 56' 7" | S.E. | -51 | -86° 48' | -86° 12' | | | | -77° 9' 188" 15' | 5 10 p.m. | Direct. | -85° 52' 5" | S.E. | -51 | -86° 48' | -86° 12' | | | | -77° 11' 189" 01' | 8 15 p.m. | Direct. | -85° 47' 4" | S.W.by W. | -33 | -86° 36' | -86° 12' | | | | -77° 9' 188" 15' | 5 10 p.m. | Direct. | -85° 59' 2" | S.E.by S. | -66 | -86° 51' | -86° 23' | | | | -77° 11' 189" 01' | 8 15 p.m. | Direct. | -85° 52' 4" | S.E.by S. | -66 | -86° 51' | -86° 23' | | | | -77° 9' 188" 15' | 5 10 p.m. | Direct. | -85° 36' 3" | S.E.by S. | -66 | -86° 51' | -86° 23' | | | | -77° 11' 189" 01' | 8 15 p.m. | Direct. | -85° 30' 9" | S.E.by S. | -66 | -86° 51' | -86° 23' | | | 2. | -77° 45' 187" 00' | 11 35 a.m. | Direct. | -86° 27' 2" | E. | +23 | -86° 04' | -86° 10' | | | | -77° 56' 186" 35' | Noon. | Direct. | -85° 46' 9" | S.E. | -51 | -86° 38' | -86° 10' | | | | -77° 56' 186" 35' | 10 p.m. | Direct. | -85° 37' 5" | S.E.by S. | -66 | -86° 43' | -86° 10' | | | | -77° 56' 186" 35' | 10 30 p.m. | Direct. | -85° 43' 0" | S.W.by S. | -66 | -86° 49' | -86° 10' | | | | -77° 56' 186" 35' | 10 30 p.m. | Direct. | -85° 34' 4" | S.by W. | -83 | -86° 57' | -86° 10' | | | 3. | -77° 17' 185" 26' | 10 00 a.m. | Direct. | -86° 57' 4" | W.S.W. | -14 | -87° 17' | -86° 49' | | | | -77° 17' 185" 26' | 11 15 a.m. | Direct. | -87° 02' 3" | W.S.W. | -14 | -87° 17' | -86° 49' | | | | -77° 17' 185" 26' | 11 15 a.m. | Direct. | -87° 04' 4" | W.S.W. | -14 | -87° 17' | -86° 49' | | | | -77° 17' 185" 26' | 11 15 a.m. | Direct. | -87° 07' 0" | W.S.W. | -14 | -87° 17' | -86° 49' | | | 4. | -77° 00' 192" 18' | 9 30 a.m. | Direct. | -86° 52' 8" | E.N.E. | +53 | -86° 00' | -85° 36' | | | | -77° 06' 192" 34' | 2 00 p.m. | Direct. | -86° 29' 5" | E.N.E. | +52 | -85° 54' | -85° 26' | | | | -77° 08' 192" 19' | 4 00 p.m. | Direct. | -86° 49' 0" | E.N.E. | +52 | -85° 54' | -85° 26' | | | 5. | -77° 24' 192" 56' | 3 00 a.m. | Direct. | -86° 27' 2" | E. | +23 | -86° 13' | -85° 45' | | | | -77° 24' 192" 56' | 4 00 a.m. | Direct. | -86° 36' 0" | E. | +23 | -86° 13' | -85° 45' | | | | -77° 24' 192" 56' | 4 00 a.m. | Direct. | -86° 34' 7" | E. | +23 | -86° 13' | -85° 45' | | | | -77° 24' 192" 56' | 4 00 a.m. | Direct. | -86° 46' 5" | E. | +23 | -86° 13' | -85° 45' | | | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|---------------------------------|--------------|----------------------------------|------------------------|----------------|---------| | 1841 | Feb. 5 | h m | Direct. | -85° 00'4 | s. | -89 | -86° 34 | -86° 06 | | | | | 11 45 A.M. | Direct. | -84° 57'2 | | | | | | | | | 2 30 P.M. | S. | -84° 53'1 | | | | | | | | | to | N. | -85° 26'3 | | | | | | | | | 4 00 P.M. | N.S. | -85° 09'9 | | | | | | | | | | | | | | | | | | | | 9 00 A.M. | Direct. | -86° 52'2 | | | | | | | | | to | S. | -87° 03'0 | | | | | | | | | 10 45 A.M.| N. | -87° 14'4 | | | | | | | | | | N.S. | -87° 29'8 | | | | | | | | | | Direct. | -85° 03'5 | | | | | | | | | | Direct. | -85° 12'1 | | | | | | | | | | | | | | | | | | | | 6 00 A.M. | Direct. | -85° 27'6 | | | | | | | | | to | S. | -85° 38'6 | | | | | | | | | 7 15 A.M. | N. | -85° 35'8 | | | | | | | | | | N.S. | -85° 29'3 | | | | | | | | | | Direct. | -86° 05'1 | | | | | | | | | | | | | | | | | | | | 11 40 A.M. | Direct. | -87° 02'5 | | | | | | | | | 1 30 P.M. | Direct. | -87° 10'6 | | | | | | | | | to | S. | -87° 04'5 | | | | | | | | | 3 45 P.M. | N. | -87° 29'6 | | | | | | | | | | N.S. | -87° 35'1 | | | | | | | | | | | | | | | | | | | | 10 35 A.M. | Direct. | -87° 16'3 | | | | | | | | | 0 20 P.M. | Direct. | -85° 27'9 | | | | | | | | | | | | | | | | | | | | 5 45 A.M. | Direct. | -85° 15'1 | | | | | | | | | to | S. | -85° 26'8 | | | | | | | | | 8 00 A.M. | N. | -85° 34'4 | | | | | | | | | | N.S. | -85° 24'6 | | | | | | | | | | Direct. | -86° 33'7 | | | | | | | | | | | | | | | | | | | | 2 50 A.M. | Direct. | -87° 16'6 | | | | | | | | | 11 40 A.M.| Direct. | -85° 55'0 | | | | | | | | | 1 00 P.M. | Direct. | -85° 29'3 | | | | | | | | | | S. | -85° 39'4 | | | | | | | | | | | | | | | | | | | | 10 15 A.M. | Direct. | -86° 04'0 | | | | | | | | | to | N. | -86° 39'8 | | | | | | | | | 11 40 A.M.| N.S. | -86° 09'0 | | | | | | | | | | | | | | | | | | | | 3 A.M. | Direct. | -86° 15'5 | | | | | | | | | 11 40 A.M.| Direct. | -86° 20'8 | | | | | | | | | 2 00 P.M. | Direct. | -86° 23'3 | | | | | | | | | | S. | -86° 23'6 | | | | | | | | | | N. | -86° 30'7 | | | | | | | | | | N.S. | -86° 30'3 | | | | | | | | | | | | | | | | | | | | 11 20 P.M. | Direct. | -86° 34'0 | | | | | | | | | | | | | | | | | | | | 11 20 A.M. | Direct. | -87° 05'3 | | | | | | | | | to | N. | -87° 13'5 | | | | | | | | | Noon | N.S. | -87° 03'1 | | | | | | | | | 4 40 P.M. | Direct. | -87° 30'1 | | | | | | | | | 7 10 P.M. | Direct. | -87° 35'3 | | | | | | | | | 9 00 P.M. | Direct. | -87° 36'4 | | | | | | | | | 11 00 P.M. | Direct. | -87° 42'0 | | | | | | ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|--------------|-----------------------------------|------------------------|-----------------|---------| | 1841 | | | | | | | | | | | Feb. 16. | -76°20'165"32 | h m 6 00 A.M. | Direct. | -87°42'8" | S.S.E. | -89°04' | -88°35' | | | | | | | | | | | | | | | | | | | -87°49'1" | N. | -89°10' | -88°35' | | | | | | | | -87°37'8" | N.S. | -88°59' | -88°35' | | | | | | | | -87°37'3" | | -88°58' | -88°35' | | | | 17. | -76°46'165"2 | 3 20 A.M. | Direct. | -88°33'2" | E.S.E. | -13° | -88°46' | | | | | | | | | | | | | | | | | | | -87°51'2" | S.S.W. | -81° | -89°12' | | | | | | | | -87°05'3" | | -88°36' | -88°19' | | | | | | | | -87°13'3" | S. | -88°44' | -88°19' | | | | | | | | -89°34'3" | N.E.by E.1/2E. | +58° | -88°36' | | | | 18. | -76°05'166"11 | 11 40 A.M. | Direct. | -89°26'5" | W. | +26° | -89°00' | | | | | | | | | | | | | | | | | | | -88°10'1" | | -87°44' | -87°53' | | | | | | | | -87°21'0" | | -88°13' | -87°53' | | | | | | | | -87°35'0" | S. | -88°27' | -88°53' | | | | | | | | -87°44'2" | N.S. | -88°36' | -88°53' | | | | | | | | -87°15'9" | | -88°08' | -88°53' | | | | 19. | -75°49'167"32 | 8 15 P.M. | Direct. | -88°01'8" | S.W. | -52° | -88°27' | | | | | | | | | | | | | | | | | | | -86°03'6" | S.W.by W.1/2W. | -27° | -86°23' | | | | | | | | -86°10'7" | | -86°35' | -86°23' | | | | 20. | -73°09'171"26 | Noon. | Direct. | -87°02'5" | S.W. | -51° | -87°54' | | | | | | | | | | | | | | | | | | | -86°01'8" | | -86°26' | -86°23' | | | | | | | | -86°03'6" | | -86°28' | -86°23' | | | | | | | | -86°10'7" | | -86°35' | -86°23' | | | | 21. | -71°04'170"07 | 9 00 A.M. | Direct. | -86°31'9" | W. | +24° | -86°08' | | | | | | | | | | | | | | | | | | | -86°15'4" | W.S.W. | -14° | -86°29' | | | | | | | | -86°30'4" | W.by S. | +5° | -86°25' | | | | 22. | -70°41'167"20 | 6 40 A.M. | Direct. | -87°28'0" | N.N.E. | +88° | -86°19' | | | | | | | | | | | | | | | | | | | -87°57'8" | | -85°51' | -85°51' | | | | | | | | -87°51'4" | | -85°51' | -85°51' | | | | | | | | -87°51'3" | | -85°51' | -85°51' | | | | 23. | -70°27'166"40 | 5 00 P.M. | Direct. | -87°02'2" | E.by N. | +39° | -86°23' | | | | | | | | | | | | | | | | | | | -87°31'9" | N.E.1/2E. | +70° | -86°22' | | | | | | | | -85°50'4" | | -87°03' | -86°19' | | | | | | | | -85°45'8" | | -86°59' | -86°19' | | | | | | | | -85°42'7" | S.S.W.1/2W. | -73° | -86°56' | | | | | | | | -85°50'0" | | -87°03' | -86°19' | | | | 24. | -70°18'167"28 | 11 40 A.M. | Direct. | -85°20'7" | S. | -89° | -86°06' | | | | | | | | | | | | | | | | | | | -85°04'7" | | -86°34' | -86°06' | | | | | | | | -84°49'2" | | -86°18' | -86°06' | | | | 25. | -70°14'167"16 | 6 30 A.M. | Direct. | -87°25'3" | N.W. | +75° | -86°10' | | | | | | | | | | | | | | | | | | | -85°54'7" | W.S.W. | -14° | -86°09' | | | | | | | | -85°13'1" | S.E. | -51° | -86°04' | | | | | | | | -85°18'8" | | -86°10' | -85°28' | | | | | | | | -85°03'9" | | -85°55' | -85°28' | | | | | | | | -85°34'1" | E.S.E. | -14° | -85°48' | | | | | | | | -86°56'0" | N.W. | +75° | -85°41' | | | | 26. | -69°52'168"09 | 5 00 P.M. | Direct. | -85°03'2" | S.by E.| -86° | -85°54' | | | | | | | | | | | | | | | | | | | -85°20'6" | | -86°47' | -85°54' | | | | | | | | -84°47'6" | | -86°14' | -85°54' | | | | | | | | -85°14'4" | S.by E.| -86° | -85°54' | | | | | | | | -86°45'6" | N.W.by W.| +64° | -85°42' | | | MDCCCXLIII. ## Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|--------------|-----------------------------------|------------------------|-----------------|---------| | 1841 | | | | | | | | | | | | Lat. | Long. | h m | Direct. | | | | | | | Mar. 1. | -69 04'167 41 | 11 30 A.M. | -86 51'5 | N.W. by W. | +64 | -85 48 | -85 26 | Much motion. | | | -69 06'167 42 | 2 00 P.M. | -86 28'5 | N.W. by W. | +64 | -85 25 | -86 37 | | | -69 08'167 44 | 2 30 P.M. | -87 40'5 | N.W. by W. | +64 | -86 03 | -85 36 | | | -69 08'167 44 | 3 00 P.M. | -87 07'0 | N.W. by W. | +64 | -86 03 | -85 36 | | | -69 08'167 44 | 3 30 P.M. | -86 49'5 | N.W. by W. | +64 | -86 03 | -85 36 | | 2. | -68 28'168 10 | 9 30 A.M. | Direct. | -86 12'0 | W. by N. | +38 | -85 34 | -85 07 | | | | S. | -86 12'1 | W. by N. | +38 | -85 34 | -85 07 | | | | N. | -86 10'2 | W. by N. | +38 | -85 34 | -85 07 | | | | N.S. | -86 32'4 | W. by N. | +38 | -85 34 | -85 07 | | | | 11 15 A.M. | Direct. | -86 24'0 | N.W. by W. | +64 | -85 20 | -85 07 | | 3. | -67 52'167 28 | 6 15 A.M. | Direct. | -85 01'8 | W. | +21 | -84 41 | -84 28 | | | | S. | -85 19'2 | W. | +21 | -84 41 | -84 28 | | | | N. | -85 38'5 | W. | +21 | -84 41 | -84 28 | | | | N.S. | -85 32'1 | W. | +21 | -84 41 | -84 28 | | | | 7 45 A.M. | Direct. | -84 55'5 | W. | +21 | -84 41 | -84 28 | | | | 11 45 A.M. | Direct. | -85 00'5 | N.E. | +72 | -83 49 | -83 35 | | 4. | -66 44'165 45 | 11 40 A.M. | Direct. | -85 05'8 | N.E. | +72 | -83 49 | -83 35 | | 5. | -65 31'167 42 | 10 30 A.M. | Direct. | -85 17'2 | N. | +91 | -83 38 | -83 35 | | | | 11 10 A.M. | Direct. | -85 08'8 | N. | +91 | -83 38 | -83 35 | | | | 11 40 A.M. | Direct. | -83 38'3 | S.S.W. | -69 | -83 35 | -83 35 | | 6. | -65 46'165 04 | 7 00 A.M. | Direct. | -83 28'3 | S.W. | -63 | -83 35 | -83 35 | | | | 11 40 A.M. | Direct. | -84 34'0 | W. | +18 | -83 35 | -83 35 | | | | 5 10 P.M. | Direct. | -84 34'0 | W. | +18 | -83 35 | -83 35 | | 7. | -65 53'162 14 | 10 00 A.M. | Direct. | -85 17'3 | N.W. | +72 | -84 05 | -83 51 | | | | 10 40 A.M. | Direct. | -85 39'2 | W.S.W. | -17 | -84 25 | -83 51 | | | | 11 20 A.M. | Direct. | -84 08'5 | W.S.W. | -17 | -84 25 | -83 51 | | 8. | -64 41'162 34 | 10 10 A.M. | Direct. | -84 33'7 | N.E. by N. | +79 | -83 15 | -82 55 | | | | S. | -84 47'7 | N.E. by N. | +79 | -83 15 | -82 55 | | | | N. | -84 52'0 | N.E. by N. | +79 | -83 15 | -82 55 | | | | N.S. | -84 32'6 | N.E. by N. | +79 | -83 15 | -82 55 | | | | 11 15 A.M. | Direct. | -84 26'5 | N.E. | +67 | -83 20 | -82 54 | | 9. | -64 22'164 32 | 7 30 A.M. | Direct. | -84 04'5 | N.N.E. | +86 | -82 39 | -82 54 | | 10. | -64 05'163 17 | Direct. | -85 01'7 | N.N.E. | +86 | -82 39 | -82 54 | | 11. | -64 13'163 18 | 9 30 A.M. | Direct. | -84 55'3 | N.W. by W. | +62 | -83 53 | -82 54 | | 12. | -63 57'161 11 | 6 00 A.M. | Direct. | -83 06'5 | S.S.W. | -69 | -84 16 | -83 32 | | | | 6 30 A.M. | Direct. | -82 44'3 | S.S.W. | -69 | -84 16 | -83 32 | | | | 7 45 A.M. | Direct. | -82 47'6 | S.S.W. | -69 | -84 16 | -83 32 | | | | 11 40 A.M. | Direct. | -83 07'0 | S.W.byW.| -25 | -83 32 | -83 32 | | 13. | -63 28'159 35 | 10 30 A.M. | Direct. | -83 09'0 | W. | +18 | -82 51 | -82 33 | | | | S. | -83 17'0 | W. | +18 | -82 51 | -82 33 | | | | N. | -83 28'7 | W. | +18 | -82 51 | -82 33 | | | | N.S. | -83 14'7 | W. | +18 | -82 51 | -82 33 | | | | 11 20 A.M. | Direct. | -81 52'5 | S.S.E. | -75 | -83 08 | -83 32 | | 14. | -62 41'156 59 | 6 45 A.M. | Direct. | -82 38'0 | S. | -85 | -84 22 | -83 54 | | | | 7 40 A.M. | Direct. | -82 42'3 | S. | -85 | -84 22 | -83 54 | | | | N. | -83 08'3 | S. | -85 | -84 22 | -83 54 | | | | N.S. | -83 19'5 | S. | -85 | -84 22 | -83 54 | ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east. | Ship's head. | Correction for ship's attraction. | Mean Inclination. Face east. | True Inclination. | Remarks | |------|----------|-------------|-----------------|----------------------------------|--------------|-----------------------------------|------------------------|-----------------|---------| | 1841 | | | | | | | | | | | Mar. 16 | -64° 11' 154° 40" | h m 11 45 A.M. | Direct. | -83° 28' 2" | s.w. ½ s. | -57° | -84° 25' | -84° 06' | | | | | 1 00 to 3 15 P.M. | Direct. | -83° 15' 0" | s.w. by s. | -64° | -84° 19' | -84° 57' | | | | | | S. | -83° 52' 8" | | | -84° 41' | -84° 06' | | | | | | N. | -83° 37' 0" | | | -84° 32' | -84° 06' | | | | | | N.S. | -83° 28' 3" | | | -84° 27' | -84° 06' | | | | | | Direct. | -83° 23' 0" | | | -84° 32' | -84° 06' | | | 17. | -64° 20' 153° 02" | 10 15 A.M. | Direct. | -83° 27' 6" | | | -84° 32' | -84° 06' | | | | | to 11 15 A.M. | S. | -83° 48' 1" | | | -84° 52' | -84° 14' | | | | | | N. | -83° 40' 9" | | | -84° 45' | -84° 14' | | | | | | N.S. | -83° 47' 2" | | | -84° 51' | -84° 14' | | | | | | Direct. | -83° 40' 7" | | | -84° 31' | -84° 14' | | | | | | s.w. | | | | -84° 31' | -84° 14' | | | 18. | -63° 54' 151° 56" | 5 45 A.M. | Direct. | -84° 44' 0" | | | -84° 34' | -84° 06' | | | | | to 7 00 A.M. | N. | -85° 14' 5" | | | -84° 06' | -84° 06' | | | | | | N.S. | -85° 35' 2" | | | -84° 06' | -84° 06' | | | 19. | -64° 18' 149° 09" | 11 40 A.M. | Direct. | -84° 00' 5" | | | -85° 05' | -84° 48' | | | | | 1 40 P.M. | Direct. | -84° 09' 7" | | | -85° 14' | -84° 48' | | | | | | S. | -84° 26' 3" | | | -85° 30' | -84° 48' | | | | | | s.w. by s. | | | | -85° 30' | -84° 48' | | | | | | N. | -84° 26' 1" | | | -85° 30' | -84° 48' | | | | | | N.S. | -84° 49' 0" | | | -85° 53' | -85° 03' | | | | | | Direct. | -84° 05' 0" | | | -85° 09' | -85° 03' | | | | | | Direct. | -84° 15' 0" | | | -85° 31' | -85° 03' | | | | | | s.s.w. | | | | -85° 31' | -85° 03' | | | 20. | -65° 15' 144° 53" | 7 40 A.M. | Direct. | -84° 55' 7" | | | -85° 47' | -85° 05' | | | | | 8 50 A.M. | Direct. | -85° 25' 8" | | | -85° 41' | -85° 05' | | | | | 10 00 A.M. | Direct. | -86° 03' 5" | | | -85° 12' | -85° 05' | | | | | | s.w. | | | | -85° 12' | -85° 05' | | | | | | w.s.w. | | | | -85° 12' | -85° 05' | | | | | | w.n.w. | | | | -85° 12' | -85° 05' | | | | | | +52° | | | | -85° 12' | -85° 05' | | | 21. | -65° 12' 144° 07" | 10 30 A.M. | Direct. | -84° 54' 3" | | | -85° 45' | -85° 10' | | | | | 11 20 A.M. | Direct. | -85° 08' 0" | | | -85° 41' | -85° 10' | | | | | 11 40 A.M. | Direct. | -85° 12' 8" | | | -85° 28' | -85° 10' | | | | | | s.w. | | | | -85° 28' | -85° 10' | | | | | | w.s.w. | | | | -85° 28' | -85° 10' | | | | | | -15° | | | | -85° 28' | -85° 10' | | | | | | N. | -85° 45' 0" | | | -86° 00' | -86° 03' | | | | | | N.S. | -85° 48' 3" | | | -86° 12' | -86° 12' | | | | | | Direct. | -85° 56' 7" | | | -85° 34' | -85° 16' | | | | | | Direct. | -85° 55' 0" | | | -85° 34' | -85° 16' | | | | | | Direct. | -85° 46' 5" | | | -85° 26' | -85° 16' | | | | | | Direct. | -85° 44' 9" | | | -85° 07' | -85° 16' | | | | | | w.by n. | | | | -85° 07' | -85° 16' | | | | | | N. ½ w. | | | | -85° 07' | -85° 16' | | | 22. | -63° 09' 139° 28" | 9 30 A.M. | Direct. | -85° 54' 5" | | | -85° 14' | -84° 46' | | | | | 11 10 A.M. | Direct. | -86° 33' 1" | | | -85° 07' | -84° 46' | | | | | | N. | -86° 57' 1" | | | -85° 19' | -84° 46' | | | | | | N.S. | -86° 25' 7" | | | -85° 00' | -84° 46' | | | | | | Direct. | -86° 02' 0" | | | -85° 00' | -84° 46' | | | | | | n.w. by w. | | | | -85° 00' | -84° 46' | | * There is an obvious error here in the degree recorded; it should be probably 86°. The observation is not employed.—E. S. | 1841 | Position | Time of day | Method employed | Observed Inclination Face east | Ship's head | Correction for ship's attraction | Mean Inclination Face east | True Inclination | Remarks | |------|----------|-------------|-----------------|-------------------------------|------------|---------------------------------|------------------------|----------------|---------| | | Lat. | Long. | | | | | | | | | Mar.22 | | | | | | | | | | | 22. | -62 46'13" 22 | 4 00 P.M. | Direct. | -85 59'7 | N.w. by w. | +62 | -85 14 | -84 46 | | | | -62 13'13" 20 | 10 15 A.M. | Direct. | -85 48'8 | | | | | | | | | to Noon. | S. | -85 37'9 | | | | | | | | | | N. | -85 58'0 | | | | | | | | | | N.S. | -85 51'5 | | | | | | | | | | Direct. | -85 10'9 | | | | | | | | | | | -85 32'5 | | | | | | | 24. | -61 20'13" 05 | 6 10 A.M. | Direct. | -85 19'1 | S. | | | | | | | | to 7 00 A.M.| S. | -85 17'7 | | | | | | | | | | N. | -85 33'9 | | | | | | | | | | N.S. | -85 46'2 | | | | | | | | | 11 40 A.M. | Direct. | -85 07'5 | | | | | | | 25. | -60 22'13" 27 | 11 45 A.M. | Direct. | -85 05'5 | N.W. | +72 | -83 54 | -83 54 | | | | -60 19'13" 20 | 3 15 P.M. | Direct. | -85 04'1 | | | | | | | | | to 4 15 P.M.| S. | -85 20'6 | | | | | | | | | | N. | -85 21'4 | | | | | | | | | | N.S. | -85 32'5 | | | | | | | 26. | -59 25'13" 14 | 10 15 A.M. | Direct. | -84 29'0 | N.W. by n. | +79 | -83 20 | -82 52 | | | | | to 11 40 A.M.| S. | -84 49'0 | | | | | | | | | | N. | -84 28'7 | | | | | | | | | | N.S. | -84 56'2 | | | | | | | | | | Direct. | -84 33'5 | | | | | | | 27. | -58 06'12" 43 | 11 40 A.M. | Direct. | -84 03'0 | N.N.W. | +86 | -82 37 | -82 09 | | | 28. | -57 22'12" 37 | 10 30 A.M. | Direct. | -82 37'7 | W. | +18 | -82 20 | -81 43 | Much motion. | | | | 11 45 A.M. | Direct. | -82 51'0 | E.N.E. | +49 | -82 02 | | | | 29. | -56 28'12" 57 | 11 30 A.M. | Direct. | -82 21'5 | N.E. | +71 | -81 11 | -80 43 | | | 30. | -55 00'13" 43 | 6 15 A.M. | Direct. | -81 28'5 | N.E. by e. | +62 | -80 27 | -80 27 | Ship very uneasy. | | | | to 7 15 A.M.| S. | -81 14'1 | | | | | | | | | | N. | -82 29'2 | | | | | | | | | | N.S. | -82 36'0 | | | | | | | | | 11 45 A.M. | Direct. | -81 41'0 | N.E. by n. | +77 | -81 19 | -80 15 | | | | | | | | | | | | | | | -55 11'13" 10 | 5 00 P.M. | Direct. | -81 26'5 | N.E. by n. | +77 | -80 10 | -80 10 | | | | -54 55'13" 50 | | S. | -81 48'5 | | | | | | | | | | N. | -81 59'7 | | | | | | | | | | S. | -81 54'7 | | | | | | | | | | N. | -81 55'9 | | | | | | | | | | N.S. | -82 05'5 | | | | | | | 31. | -54 41'34" 54 | 11 40 A.M. | Direct. | -79 45'5 | E. 1/2 N. | +27 | -79 19 | -79 19 | | | | 0 15 P.M. | Direct. | -80 25'0 | E. | +19 | | | | | | | 1 00 P.M. | Direct. | -80 00'0 | E. 1/2 N. | +27 | | | | | | | 2 00 P.M. | Direct. | -81 21'3 | S. | | | | | | | | 3 30 P.M. | | N. | -81 50'2 | | | | | | | | | | N.S. | -81 46'4 | | | | | | | | | | Direct. | -81 26'6 | N.W. | +70 | -80 36 | -80 36 | | | | | | | -81 22'7 | | | | | | ### Observations of Inclination. (Continued.) | Year | Position | Time of day | Method employed | Observed Inclination. Face east | Ship's head | Correction for ship's attraction | Mean Inclination. Face east | True Inclination | Remarks | |------|----------|-------------|-----------------|---------------------------------|------------|---------------------------------|---------------------|----------------|---------| | 1841 | Lat. | Long. | | | | | | | | | April 1 | -53° 13' | 135° 18' | h m | Direct. | -80° 48.5' | +82 | -79° 37' | -79° 09' | | | | | | 9 00 A.M. | S. | -81° 20.1' | | | | | | | | | to | N. | -81° 08.2' | | | | | | | | | 11 45 A.M. | N.S. | -80° 46.3' | | | | | | | | | | Direct. | -80° 51.2' | | | | | | 2. | -51° 16' | 136° 50' | 6 00 A.M. | Direct. | -79° 55.8' | +82 | -78° 27' | -77° 59' | | | | | | to | S. | -79° 49.5' | | | | | | | | | 7 15 A.M. | N. | -79° 47.7' | | | | | | | | | | N.S. | -79° 45.0' | | | | | | 3. | -48° 56' | 138° 34' | 11 45 A.M. | Direct. | -78° 41.6' | +81 | -77° 22' | -76° 54' | Much sea. | | | | | 2 00 P.M. | Direct. | -78° 50.3' | | | | | | | | | to | N. | -79° 09.4' | | | | | | | | | 4 00 P.M. | N.S. | -78° 13.0' | | | | | | 4. | -46° 55' | 139° 55' | 7 20 to | Direct. | -77° 05.5' | +69 | -76° 10' | -75° 42' | Heavy sea, | | | | | 8 20 A.M. | N. | -77° 29.8' | | | | ship rolling | | | | | | N.S. | -77° 20.7' | | | | deep. | | | | | | Direct. | -77° 00.5' | | | | | | | | | | N. | -77° 39.8' | | | | | | | | | | N.S. | -77° 37.9' | | | | | | | | | | S. | -77° 37.5' | | | | | | | | | | N. | -77° 33.2' | | | | | | | | | | N.S. | -77° 49.1' | | | | | | | | | | Direct. | -78° 11.5' | | | | | | | | | | Direct. | -77° 23.0' | +69 | -75° 47' | | Heavy sea. | | | | | | S. | -76° 33.5' | | | | | | | | | | N. | -76° 29.0' | | | | | | | | | | N.S. | -77° 18.0' | | | | | | | | | | Direct. | -76° 48.5' | | | | Much mo- | | | | | | S. | -76° 29.7' | | | | tion. | | | | | | N. | -76° 10.2' | | | | | | | | | | N.S. | -76° 50.6' | | | | | | | | | | Direct. | -76° 04.0' | | | | | | | | | | S. | -75° 02.2' | | | | | | | | | | N. | -75° 11.5' | | | | | | | | | | N.S. | -75° 03.2' | | | | | | | | | | Direct. | -75° 49.5' | | | | | | | | | | S. | -75° 28.5' | | | | | | | | | | N.E. by E. | -74° 57.6' | +60 | -74° 24' | | | | | | | | N. | -75° 20.9' | | | | | | | | | | N.E. by E. | -73° 49.8' | +58 | -72° 52' | | Running | | | | | | S. | -73° 35.5' | | | | along the | | | | | | N.S. | -73° 42.0' | | | | land. | Observations of the Intensity of the Magnetic Force made in Her Majesty's Ship Erebus, from September 1840 to April 1841, with Needle R. F. 4. Observers Captain Ross and Lieutenant Smith, R.N. | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|---------------------|-------------|------------|----------|---------------------------------|-------------------|---------| | 1840 | | | | | | | | | | | | Sept. 17 | Magnetic Observatory, Hobarton. | Deflector S. | 50° 00' 9" | 52° | Observed on shore* | 1·820 | 1·820 | | | | | | -42° 52' 147" 24 | wt. ½ gr. | 2° 41' 4" | 52° | | | | | | | | | | wt. 1 gr. | 5° 23' 7" | 52° | | | | | | | | | | wt. 1½ gr. | 8° 14' 6" | 52° | | | | | | | | | | wt. 2 grs. | 10° 49' 6" | 52° | | | | | | | | | | wt. 3 grs. | 16° 15" | 52° | | | | | | | | Oct. 17 | S. | 49° 23' | 54° | S.E. by s. | 1·869 | -0·035 | 1·834 | | | | | S. | 49° 51' | 54° | W. | 1·833 | -0·003 | 1·830 | | | | | S. | 49° 27' 2" | 54° | S. by E. | 1·864 | -0·043 | 1·821 | | | | | S. | 49° 39' | 54° | S.S.E. | 1·849 | -0·039 | 1·810 | | | | | S. | 49° 50' 9" | 51° | W.N.W. | 1·833 | +0·008 | 1·841 | | | | | S. | 49° 48' 8" | 51° | S.E. | 1·835 | -0·031 | 1·804 | | | | | S. | 50° 19' 8" | 48° | N. | 1·792 | +0·028 | 1·820 | | | | | S. | 50° 23' 7" | 48° | N.N.E. | 1·787 | +0·024 | 1·811 | | | | | S. | 50° 21' 8" | 48° | N.E. | 1·789 | +0·020 | 1·809 | | | | | S. | 50° 09' 9" | 48° | E.N.E. | 1·816 | +0·008 | 1·824 | | | | | S. | 49° 53' 5" | 48° | E. | 1·828 | -0·003 | 1·825 | | | | | S. | 50° 09' 4" | 48° | N.N.W. | 1·807 | +0·024 | 1·831 | | | | | S. | 50° 12' 6" | 48° | N.W. | 1·803 | +0·020 | 1·823 | | | | | S. | 49° 40' | 48° | W.S.W. | 1·848 | -0·017 | 1·831 | | | | | S. | 49° 52' 2" | 48° | W. | 1·831 | -0·003 | 1·828 | | | | | S. | 49° 56' 2" | 48° | W.N.W. | 1·826 | +0·008 | 1·834 | | | | | S. | 49° 28' 8" | 48° | S.W. | 1·862 | -0·031 | 1·831 | | | | | S. | 49° 28' 2" | 48° | S.S.W. | 1·863 | -0·039 | 1·824 | | | | | S. | 49° 27' 0" | 48° | S. | 1·864 | -0·046 | 1·818 | | | | | S. | 49° 24' 5" | 48° | S.S.E. | 1·867 | -0·039 | 1·828 | | | | | S. | 49° 39' 5" | 48° | S.E. | 1·849 | -0·031 | 1·818 | | | | | S. | 49° 52' 7" | 48° | E.S.E. | 1·830 | -0·017 | 1·813 | | | | Nov. 13 | S. | 49° 23' 8" | 54° | E.S.E. | 1·868 | -0·017 | 1·851 | | | | | N. | 47° 05' 9" | 54° | E.S.E. | 1·855 | -0·017 | 1·838 | 1·844 | | | | S. | 49° 34' 5" | 45° | S.E. | 1·855 | -0·031 | 1·824 | | | | | N. | 46° 50' 5" | 45° | S.E. | 1·872 | -0·031 | 1·841 | | | | | S. | 49° 56' 9" | 51° | E. | 1·824 | -0·003 | 1·821 | | | | | N. | 46° 53' 5" | 51° | E. | 1·869 | -0·003 | 1·866 | | | | | S. | 49° 50' 7" | 57° | E.S.E. | 1·833 | -0·017 | 1·816 | | | | | N. | 47° 17' | 57° | E.S.E. | 1·841 | -0·017 | 1·824 | | | | | S. | 49° 52' | 51° | | | | | | | | | N. | 47° 15' | 51° | | | | | | | | | S. | 49° 34' | 50° | S.E.by E.½ E. | 1·843 | -0·020 | 1·823 | | | | | N. | 46° 47' 2" | 50° | | | | | | | * The angles of deflection with 4, 5 and 6 grains, not having been observed at Hobarton, have been computed from the angles produced by the five weights which were employed at that station; they are as follows: gr. 4... 22° 06' 5... 28° 03' 5" 6... 34° 21' ### Observations of the Magnetic Force. (Continued.) | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|---------------------|-------------|------------|----------|----------------------------------|---------------------|---------| | 1840 | Nov. 19 | -50°28'164°9 | S. | 49°11'49" | E. | 1·884 | -0·003 | 1·881 | 1·858 | | | | | N. | 47°20'49" | W.N.W. | 1·838 | -0·003 | 1·835 | | | | | | S. | 49°44'2" | | 1·842 | +0·008 | 1·850 | | | | | | N. | 47°27'6" | | 1·830 | +0·008 | 1·838 | | | | | | wt. ½ gr. | 2°33'9" | | 1·830 | | | | | | | | wt. 1 gr. | 5°13" | | 1·876 | +0·013 | 1·889 | | | | | | wt. 2 grs. | 10°27'3" | | 1·884 | +0·013 | 1·897 | | | | | | wt. 3 grs. | 15°28'6" | | 1·909 | +0·013 | 1·922 | | | | | | At anchor. | | | 1·862 | -0·037 | 1·825 | | | | | | S. | 49°29'2" | s.s.w. | 1·862 | -0·037 | 1·825 | | | | | | S. | 49°50'6" | w.s.w. | 1·833 | -0·013 | 1·830 | | | | | | S. | 49°29" | | 1·862 | | | | | | | | N. | 46°50'2" | | 1·873 | | | | | | | | wt. ½ gr. | 2°33'5" | | 1·844 | | | | | | | | wt. 1 gr. | 5°18'4" | | 1·867 | | | | | | | | wt. ½ gr. | 8°02'2" | | 1·856 | | | | | | | | wt. 2 grs. | 10°36'8" | | 1·851 | | | | | | | | wt. 3 grs. | 15°58'3" | | 1·778 | | | | | | | | On shore. | | | 1·818 | | | | | | | | S. | 50°31" | | 1·818 | | | | | | | | N. | 47°38" | | 1·818 | | | | | | | | S. | 47°50'7" | | 1·981 | | | | | | | | N. | 45°3'6" | | 1·993 | | | | | | | | S. | 49°49'8" | | 1·834 | | | | | | | | S. | 49°28" | | 1·863 | | | | | | | | S. | 49°27" | | 1·864 | | | | | | | | N. | 47°31'7" | | 1·826 | | | | | | | | S. | 59°56" | | 1·826 | | | | | | | | N. | 57°19'2" | | 1·826 | | | | | | | | S. | 49°35" | | 1·854 | -0·030 | 1·824 | | | | | | S. | 49°05'9" | | 1·891 | -0·036 | 1·855 | | | | | | S. | 49°57'2" | | 1·824 | -0·008 | 1·816 | | | | | | S. | 49°21'9" | | 1·871 | -0·041 | 1·830 | | | | | | S. | 49°19" | | 1·874 | -0·036 | 1·838 | | | | | | S. | 49°29'2" | | 1·862 | -0·030 | 1·832 | | | | | | S. | 49°29'5" | | 1·862 | -0·015 | 1·847 | | | | | | S. | 49°44'9" | | 1·841 | -0·003 | 1·838 | | | | | | S. | 49°46'7" | | 1·838 | +0·008 | 1·846 | | | | | | S. | 49°58" | | 1·823 | +0·018 | 1·841 | | | | | | S. | 50°06'9" | | 1·810 | +0·021 | 1·831 | | | | | | S. | 49°51'4" | | 1·832 | +0·026 | 1·858 | | | | | | S. | 50°01'8" | | 1·817 | +0·021 | 1·838 | | | | | | S. | 50°16'3" | | 1·797 | +0·018 | 1·815 | | | | | | S. | 49°27'2" | | 1·864 | -0·030 | 1·834 | | * Mean of the results at Auckland Island, omitting those which appear to have been affected by excessive local attraction: November 21 and 26, on board .. 1·864 November 24, on shore .. 1·859 November 30, on shore .. 1·847 December 6, 7 and 8, on board .. 1·836 1·851. ### Observations of the Magnetic Force. (Continued.) | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|---------------------|-------------|------------|----------|----------------------------------|-------------------|---------| | Dec. 14 | Campbell Island* at anchor. | S. | 50° 01' 4" | 50° | N.W. | 1·819 | +·018 | 1·837 | 1·846 | 1·846 | | | | S. | 49° 39' 2" | 50° | W. | 1·849 | −·003 | 1·846 | 1·846 | 1·846 | | | | S. | 49° 04' 5" | 52° | S.S.W. | 1·893 | −·037 | 1·856 | 1·856 | 1·856 | | | | S. | 49° 20' 5" | 55° | | 1·873 | | | | | | | | N. | 46° 10' 8" | 55° | | 1·917 | | | | | | | | wt. ½ gr. | 2° 35' 3" | 55° | | | | | | | | | | wt. 2 grs. | 10° 12' 1" | 55° | | | | | | | | | | wt. 3 grs. | 15° 30' 2" | 55° | | | | | | | | | | wt. ½ gr. | 2° 32' 9" | 52° | Observed on shore. | 1·930 | | | 1·909 | | | | | wt. 1 gr. | 4° 59' 2" | 52° | | 1·906 | | | | | | | | wt. 2 grs. | 10° 12' 6" | 52° | | 1·963 | | | | | | | | wt. 3 grs. | 15° 30' 2" | 52° | | 1·929 | | | | | | | | S. | 49° 17' | 52° | | 1·906 | | | | | | | | N. | 46° 45' 7" | 53° | | 1·877 | | | | | | | | S. | 49° 13' 6" | 44° | S.S.E. | 1·878 | | | | | | | | N. | 46° 18' 5" | 44° | S.S.E. ½ E. | 1·881 | −·037 | 1·844 | | | | | | N. | 45° 48' | 48° | s. by w. | 1·908 | −·034 | 1·874 | | | | | | N.S. | 22° 39' 5" | 48° | | 1·943 | −·040 | 1·903 | | | | | | N. | 45° 42' 7" | 38° | S.S.E. | 1·949 | −·035 | 1·914 | | | | | | N.S. | 22° 26' | | | 1·948 | −·037 | 1·911 | | | | | | N. | 45° 44' 5" | 42° | s. by E. | | | | | | | | | N.S. | 22° 25' 6" | | | 1·951 | −·040 | 1·911 | 1·920 | | | | | S. | 48° 17' 7" | 41° | s. | 1·969 | −·040 | 1·929 | 1·920 | | | | | N. | 45° 25' 2" | | | 1·959 | −·031 | 1·928 | 1·936 | | | | | N.S. | 22° 31' 7" | | S.S.W. | 1·975 | −·031 | 1·944 | 1·936 | | | | | S. | 48° 11' 5" | 39° | E. | | | | | | | | | N. | 45° 20' 2" | | | 1·978 | −·027 | 1·951 | | | | | | N.S. | 22° 29' 5" | | | 1·972 | −·029 | 1·943 | 1·951 | | | | | N.S. | 22° 31' 5" | 37° | S.E. ½ S. | 1·988 | −·029 | 1·959 | 1·951 | | | | | N. | 45° 16' 9" | 36° | | 1·956 | −·027 | 1·929 | | | | | | N.S. | 22° 27' | 36° | S.E. | 1·980 | −·027 | 1·953 | | | | | | S. | 47° 59' 2" | 42° | | 1·988 | −·032 | 1·956 | 1·960 | | | | | N. | 45° 08' 1" | 41° | S.E. by s. | | | | | | | | | N.S. | 22° 27' | 40° | | 1·997 | +·011 | 2·008 | | | | | | S. | 48° 13' 7" | 40° | | 2·001 | −·032 | 1·969 | 1·983 | | | | | N. | 45° 15' 1" | 40° | | 2·029 | −·032 | 1·997 | 1·983 | | | | | N.S. | 22° 29' 3" | 39° | S.E. by s. | | | | | | | | | N. | 45° 08' 4" | 35° | | 1·988 | −·032 | 1·956 | 1·960 | | | | | N.S. | 22° 27' 6" | 35° | | 1·997 | +·011 | 2·008 | | | | | | N. | 45° 00' | 46° | N. | | | | | | | | | N.S. | 22° 15' 7" | 45° | | 2·001 | −·032 | 1·969 | 1·976 | | | | | S. | 47° 33' 2" | 34° | | 2·029 | −·032 | 1·997 | 1·983 | | | | | N. | 44° 30' 6" | 34° | | 1·988 | −·028 | 1·960 | 1·973 | | | | | N.S. | 22° 0' 5" | 34° | | 2·016 | −·030 | 1·986 | 1·973 | | | | | N.S. | 22° 15' 2" | 34° | | | | | | | | | | S. | 47° 53' 9" | 33° | | | | | | | | | | N. | 44° 34' 2" | 33° | S.S.W. ½ W. | | | | | | | | | N.S. | 22° 11' 7" | 33° | | 1·978 | −·026 | 1·952 | 1·976 | | | | | S. | 47° 45' | 34° | S.S.W. | 2·026 | −·026 | 2·000 | 1·976 | | | | | N. | 44° 42' 3" | 34° | s. by w. | 1·988 | −·028 | 1·960 | 1·973 | | * Mean of the results at Campbell Island: December 14 and 15, on shore.. 1·909 December 14 and 16, on board.. 1·846 ### Observations of the Magnetic Force. (Continued.) | Year | Month | Day | Latitude | Longitude | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|-------|-----|----------|-----------|-----------------|--------------------|--------------|------------|----------|----------------------------------|-------------------|---------| | 1840 | Dec. 30 | -64° 30' 17" 25' 51" | N.S. | 22° 17' 6" 33" | s. by w. | 2·018 | -0·030 | 1·988 | 1·988 | | | | | S. | 47° 17' 44" | 2·018 | -0·030 | 1·988 | 1·988 | | | | | N. | 44° 41' 1" | 2·018 | -0·030 | 1·988 | 1·988 | | | | | N.S. | 21° 26' 7" | s. | 2·039 | -0·028 | 2·011 | | | | | S. | 46° 58' 5" | 2·026 | -0·028 | 1·998 | 1·995 | | | | | N. | 44° 34' | 2·005 | -0·023 | 1·982 | | | | | N.S. | 21° 36' 2" | s. by w. | 2·012 | -0·023 | 1·989 | | | | | S. | 47° 29' 5" | 2·005 | -0·023 | 1·982 | | | | | N. | 44° 47' 1" | 2·012 | -0·023 | 1·989 | | | | | N.S. | 21° 52' 3" | s. by w. | 2·020 | -0·027 | 1·993 | | | | | S. | 47° 15' 8" | 2·030 | -0·027 | 2·003 | 2·008 | | | | | N. | 44° 30' 1" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 43' 5" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 13' | 2·023 | +0·006 | 2·029 | | | | | N.S. | 22° 05' 4" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 51' 5" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 13' 9" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 56' 1" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 01' 6" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 14' 5" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 22° 37' 5" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 00' 5" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 20' 5" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 54' 1" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 11' 7" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 35' 9" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 55" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 26' 1" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 15' 8" | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 16' 5" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 21' 1" | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 09' 1" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 04' 7" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 55" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 03' 3" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 22' 6" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 22° 00' 1" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 15' 7" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 17' 1" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 54' 8" | s. | 2·023 | +0·006 | 2·029 | | | | | wt. ½ gr. | 2° 28' | 2·023 | +0·006 | 2·029 | | | | | wt. 3 grs. | 14° 34' 3" | 2·023 | +0·006 | 2·029 | | | | | wt. 6 grs. | 30° 38' 7" | 2·023 | +0·006 | 2·029 | | | | | S. | 47° 06' | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 16' | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 48' 2" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 46° 58' 9" | 2·023 | +0·006 | 2·029 | | | | | N. | 43° 49' 2" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 22° 10" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 46° 47' 5" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 07' 3" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 22° 03' 5" | s. | 2·023 | +0·006 | 2·029 | | | | | S. | 46° 49' 9" | 2·023 | +0·006 | 2·029 | | | | | N. | 44° 08' 6" | 2·023 | +0·006 | 2·029 | | | | | N.S. | 21° 53' 6" | s. by w. | 2·023 | +0·006 | 2·029 | --- **MDCCXLIII.** | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|--------------------|-------------|-------------|----------|---------------------------------|-------------------|---------| | 1841 | Jan. 12 | -71° 47' 170° 52' | S. | 46° 41' 5" | 34° | W.S.W. | 2.057 | -0.011 | 2.046 | 2.056 | | | | | N. | 43° 44' 1" | 33° | | 2.078 | -0.011 | 2.067 | | | | | | S. | 47° 24' 5" | 33° | | 2.011 | -0.005 | 2.006 | | | | | | N. | 43° 47' 4" | 33° | E. by N. ½ N. | 2.075 | -0.005 | 2.070 | | | | | | N.S. | 21° 47' 9" | 33° | | | | | | | | | | S. | 47° 25' 2" | 33° | | 2.010 | -0.007 | 2.003 | | | | | | N.S. | 21° 45' 2" | 33° | | | | | | | | | | N. | 44° 02" | 33° | E. | 2.060 | -0.007 | 2.053 | | | | | | S. | 46° 52' 4" | 28° | | 2.044 | -0.019 | 2.025 | | | | | | N. | 44° 04" | 28° | S. by W. | 2.058 | -0.019 | 2.039 | | | | | | N.S. | 21° 47' 5" | 28° | | | | | | | | | | N. | 44° 26' 7" | 30° | E. | 2.033 | -0.007 | 2.026 | | | | | | N.S. | 21° 36' 5" | 30° | | | | | | | | | | S. | 46° 30' 1" | 31° | S.E. by E. | 2.070 | -0.014 | 2.056 | | | | | | N. | 44° 28' 7" | 31° | | 2.031 | -0.011 | 2.020 | | | | | | N.S. | 22° 01' 5" | 31° | E.S.E. | | | | | | | | | S. | 46° 49' 8" | 41° | | 2.047 | -0.015 | 2.032 | | | | | | N. | 44° 07' 9" | 41° | S.W. by W. | 2.034 | -0.015 | 2.039 | | | | | | N.S. | 21° 54' 8" | 41° | | | | | | | | | | S. | 46° 53" | 34° | | 2.044 | -0.018 | 2.026 | | | | | | N. | 43° 51' 8" | 34° | S. by E. ½ E. | 2.070 | -0.018 | 2.052 | | | | | | N.S. | 21° 50' 1" | 34° | | | | | | | | | | S. | 46° 31' 9" | 34° | | 2.067 | -0.014 | 2.053 | | | | | | N. | 43° 56' 3" | 34° | S.E. | 2.066 | -0.014 | 2.052 | | | | | | N.S. | 21° 37' 7" | 34° | | | | | | | | | | S. | 46° 50' 7" | 30° | | 2.046 | -0.019 | 2.027 | | | | | | N. | 43° 41' 8" | 30° | S. by E. | 2.080 | -0.019 | 2.061 | | | | | | N.S. | 21° 39" | 30° | | | | | | | | | | S. | 46° 42" | 31° | | 2.056 | -0.004 | 2.052 | | | | | | N. | 44° 06" | 31° | N. by E. | 2.056 | -0.004 | 2.052 | | | | | | N.S. | 22° 08' 6" | 31° | | | | | | | | | | S. | 46° 57' 7" | 32° | | 2.041 | -0.017 | 2.024 | | | | | | N. | 44° 00" | 32° | | 2.062 | -0.017 | 2.045 | | | | | | N.S. | 21° 52' 2" | 32° | S. by E. | | | | | | | | | N. | 44° 07" | 29° | | 2.055 | -0.017 | 2.038 | | | | | | N.S. | 21° 27' 8" | 29° | | | | | | | | | | S. | 46° 51' 7" | 29° | | 2.045 | -0.018 | 2.027 | | | | | | N. | 43° 59" | 29° | S. ½ W. | 2.063 | -0.018 | 2.045 | | | | | | N.S. | 21° 47" | 29° | | | | | | | | | | S. | 46° 48' 6" | 30° | | 2.048 | -0.007 | 2.041 | | | | | | N. | 44° 05' 7" | 30° | E. | 2.056 | -0.007 | 2.049 | | | | | | N.S. | 21° 50' 3" | 29° | | | | | | | | | | S. | 46° 42" | 30° | | 2.056 | -0.016 | 2.040 | | | | | | N. | 43° 48' 6" | 28° | S.S.E. | 2.073 | -0.016 | 2.057 | | | | | | N.S. | 22° 01" | 27° | | | | | | | | | | S. | 47° 01' 2" | 33° | | 2.036 | -0.015 | 2.026 | | | | | | N. | 44° 07' 3" | 33° | S.E. | 2.055 | -0.015 | 2.040 | | | | | | N.S. | 21° 44' 4" | 33° | | | | | | | | | | S. | 46° 59' 9" | 37° | | 2.037 | -0.008 | 2.029 | | | | | | N. | 44° 03' 7" | 37° | E. | 2.058 | -0.008 | 2.050 | | | | | | N.S. | 22° 0° 0" | 37° | | | | | | | | | | S. | 47° 19' 9" | 29° | | 2.015 | -0.005 | 2.015 | | | | | | N. | 44° 32' 2" | 29° | N. by W. | 2.028 | -0.005 | 2.023 | | | | | | N.S. | 21° 51' 9" | 28° | | | | | | Much motion. Observations indifferent. Two points out of the meridian. | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|--------------------|-------------|------------|----------|---------------------------------|---------------------|---------| | Jan. 31 | -77° 04' 188 18 | S. | 47° 43'6" | 25° | N.E. by N. | 1·989 | -0·001 | 1·988 | | Feb. 1 | -77° 04' 188 30 | N. | 44° 23'5" | | 2·036 | -0·001 | 2·035 | | | | N.S. | 22° 26'6" | | | | | | | | | S. | 47° 06'9" | | 2·029 | -0·016 | 2·013 | | | | N. | 44° 13'5" | | 2·047 | -0·016 | 2·031 | | | | N.S. | 22° 14'8" | | | | | | | Feb. 3 | -77° 09' 188 15 | wt. 6 grs. | 30° 45' | 30° | S.E. | 2·014 | | | | | | wt. 1 gr. | 4° 42' | 31° | | | | | | | | wt. ½ gr. | 2° 27'6" | 31° | | | | | | Feb. 4 | -77° 17' 185 26 | S. | 46° 59'9" | 33° | W.S.W. | 2·037 | -0·012 | 2·025 | | | | N. | 44° 02'6" | 34° | 2·034 | -0·012 | 2·022 | | | | N.S. | 21° 55'6" | 35° | | | | | | Feb. 5 | -77° 00' 192 18 | S. | 46° 57'2" | | E. by N. | 2·040 | -0·006 | 2·034 | | | | N. | 44° 16'3" | | 2·045 | -0·006 | 2·039 | | | | N.S. | 22° 00'1" | | | | | | | Feb. 6 | -77° 10' 192 48 | S. | 47° 01'7" | 23° | S. | 2·035 | -0·006 | 2·029 | | | | N. | 44° 00' | 21° | 2·062 | -0·006 | 2·056 | | Feb. 7 | -77° 14' 192 02 | S. | 46° 57'8" | 24° | E. | 2·039 | -0·007 | 2·032 | | | | N. | 44° 14'2" | | 2·047 | -0·007 | 2·040 | | | | N.S. | 22° 10' | 19° | | | | | | Feb. 8 | -77° 09' 188 50 | S. | 46° 41'5" | 20° | S. | 2·056 | -0·021 | 2·035 | | | | N. | 44° 33' | 19° | 2·027 | -0·021 | 2·006 | | Feb. 9 | -76° 58' 180 40 | N.S. | 22° 07'8" | 18° | E.N.E. | 2·028 | -0·005 | 2·033 | | | | S. | 47° 07'7" | | 2·055 | -0·005 | 2·050 | | Feb. 10 | -77° 47' 187 18 | N. | 44° 06'6" | 24° | S. by W. | 2·046 | -0·019 | 2·027 | | | | N.S. | 21° 58'9" | | 2·062 | -0·019 | 2·043 | | Feb. 11 | -77° 39' 187 06 | S. | 46° 50'9" | 27° | | | | | | | | N. | 44° 00'4" | 24° | | | | | | | | N.S. | 22° 02'3" | 23° | | | | | | Feb. 12 | -76° 55' 188 40 | S. | 47° 03' | 34° | | | | | | | | N. | 44° 23'2" | 33° | | | | | | | | N.S. | 22° 03'4" | 32° | | | | | | Feb. 13 | -76° 50' 183 26 | wt. 6 grs. | 30° 30'9" | | | | | | | | | wt. 3 grs. | 14° 14'6" | | | | | | | | | wt. 2 grs. | 9° 15'6" | | | | | | | | | wt. 1 gr. | 6° 15'1" | | | | | | | | | wt. ½ gr. | 2° 27'8" | | | | | | | Feb. 14 | -76° 16' 175 50 | wt. 6 grs. | 30° 34'7" | 28° | | | | | | | | wt. 3 grs. | 14° 37' | | | | | | | | | wt. 2 grs. | 9° 30'9" | | | | | | | | | wt. 1 gr. | 4° 34'2" | | | | | | | | | wt. ½ gr. | 2° 13'2" | | | | | | | Feb. 15 | -76° 03' 169 30 | S. | 46° 55'5" | 33° | S. by E. | 2·041 | -0·019 | 2·022 | | | | N. | 44° 13'9" | 29° | 2·047 | -0·019 | 2·028 | | | | N.S. | 21° 55'9" | 29° | 2·041 | -0·019 | 2·022 | | Feb. 16 | -76° 20' 165 32 | S. | 46° 47' | 21° | N.W. | 2·050 | -0·002 | 2·048 | | | | N. | 44° 13'2" | 25° | 2·048 | -0·013 | 2·035 | | | | N.S. | 21° 47'5" | 24° | | | | | | | | S. | 46° 55'1" | 34° | S.E. by E. | 2·042 | -0·017 | 2·025 | | | | N. | 44° 33'7" | 33° | 2·026 | -0·017 | 2·009 | | | | N.S. | 22° 09'9" | 32° | | | | | | | | N. | 44° 08'5" | 30° | S. | 2·053 | -0·020 | 2·033 | | | | N.S. | 22° 00'2" | 30° | | | | | | | | S. | 46° 45'9" | 30° | S.S.E. | 2·051 | -0·012 | 2·039 | | | | N. | 44° 08'4" | 30° | 2·054 | -0·012 | 2·042 | | | | N.S. | 22° 09'6" | 29° | | | | | Ship's motion very considerable. Much motion. | Year | Month | Day | Latitude | Longitude | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|-------|-----|----------|-----------|-----------------|--------------------|--------------|------------|----------|---------------------------------|-------------------|---------| | 1841 | Feb. | 19 | -75° 03' | 168° 44" | S. | 46° 38' 8" | 35 | s.w. | 2-059 | -0.011 | 2-048 | | | | | | | | N. | 44° 16' 9" | 32 | | 2-044 | -0.011 | 2-033 | | | | | | | | N.S. | 22° 03' 2" | 31 | | 2-041 | -0.011 | 2-030 | | | | | | | | S. | 46° 55' 7" | 32 | s.w.by w. | 2-041 | -0.011 | 2-030 | | | | | | | | N. | 44° 07' 7" | 30 | | 2-055 | -0.011 | 2-044 | | | | | | | | S. | 47° 04' | 27 | | 2-033 | -0.007 | 2-026 | | | | | | | | N. | 44° 28' 2" | 26 | W. | 2-032 | -0.007 | 2-025 | | | | | | | | N.S. | 22° 12' | 26 | | 2-036 | -0.001 | 2-035 | Much motion. | | | | | | | S. | 47° 01' 4" | 24 | N.N.E. | 2-073 | -0.001 | 2-072 | | | | | | | | N. | 43° 48' 5" | 23 | | 2-055 | -0.018 | 2-037 | | | | | | | | N.S. | 22° 01' 3" | 24 | | 2-052 | -0.018 | 2-034 | | | | | | | | S. | 46° 43' 4" | 26 | S.S.W. ½ W. | 2-055 | -0.018 | 2-037 | | | | | | | | N. | 44° 09' 6" | 25 | | 2-052 | -0.018 | 2-034 | | | | | | | | N.S. | 22° 12' 1" | 24 | | 2-024 | -0.020 | 2-004 | Much motion. | | | | | | | N. | 44° 35' 3" | 22 | S. | 2-050 | -0.016 | 2-034 | Unsteady. | | | | | | | N.S. | 21° 41' 1" | 19 | | 2-055 | -0.007 | 2-048 | | | | | | | | S. | 46° 46' 5" | 30 | S.E. | 2-044 | -0.007 | 2-037 | | | | | | | | N.S. | 21° 59' 9" | 29 | | 2-033 | -0.019 | 2-014 | | | | | | | | N. | 44° 27' 1" | 22 | S. by E. | 2-029 | -0.002 | 2-027 | | | | | | | | N.S. | 21° 55' 9" | 21 | | 2-048 | -0.005 | 2-043 | | | | | | | | N. | 44° 31' | 24 | N.W. by W.| 2-054 | -0.002 | 2-052 | | | | | | | | N.S. | 46° 50' 3" | 27 | W. by N. | 2-055 | -0.007 | 2-048 | | | | | | | | N. | 44° 07' 8" | 26 | N.W. by W.| 2-044 | -0.007 | 2-037 | | | | | | | | N.S. | 22° 20' | 28 | | 2-035 | +0.006 | 2-041 | A good deal of motion. | | | | | | | S. | 46° 43' 4" | 16 | W. | 2-002 | +0.003 | 2-005 | | | | | | | | N. | 44° 17' 5" | 14 | N.E. by N.| 2-017 | +0.004 | 2-021 | | | | | | | | N.S. | 22° 27' 9" | 14 | | 2-041 | +0.004 | 2-045 | | | | | | | | N. | 44° 25' 1" | 28 | N. | 2-029 | -0.022 | 2-007 | | | | | | | | N.S. | 22° 23' 2" | 27 | | 2-035 | -0.022 | 2-013 | | | | | | | | S. | 47° 31' 7" | 34 | N.W. | 2-005 | +0.002 | 2-007 | | | | | | | | S. | 47° 17' 9" | 35 | N.E. by N.| 2-027 | +0.002 | 2-029 | | | | | | | | N. | 44° 19' 6" | 33 | | 2-041 | +0.004 | 2-045 | | | | | | | | N.S. | 22° 09' 6" | 34 | | 2-029 | -0.022 | 2-007 | | | | | | | | S. | 47° 29' 3" | 31 | N.W. by W.| 2-027 | +0.002 | 2-029 | | | | | | | | N. | 44° 33' | 30 | | 2-035 | -0.022 | 2-013 | | | | | | | | N.S. | 22° 29' 8" | 30 | | 2-029 | -0.022 | 2-013 | | | | | | | | S. | 47° 06' 8" | 31 | S. by W. | 2-035 | -0.022 | 2-013 | | | | | | | | N. | 44° 25' 4" | 30 | | 2-023 | -0.012 | 2-011 | | | | | | | | N.S. | 21° 59' | 30 | | 2-045 | -0.012 | 2-033 | | | | | | | | S. | 47° 13' | 28 | W. | 2-034 | -0.024 | 2-010 | | | | | | | | N. | 44° 16' 7" | 28 | | 2-039 | -0.024 | 2-015 | | | | | | | | N.S. | 21° 49' 7" | 28 | | 2-033 | -0.020 | 2-013 | | | | | | | | S. | 47° 02' 7" | 33 | S. ½ W. | 2-033 | -0.020 | 2-013 | | | | | | | | N. | 44° 22' 3" | 31 | | 2-029 | -0.020 | 2-009 | | | | | | | | N.S. | 21° 40' 8" | 31 | | 2-047 | -0.020 | 2-027 | | | | | | | | S. | 47° 04' 3" | 22 | S.W. by s.| 2-058 | -0.020 | 2-038 | | | | | | | | N. | 44° 31' | 22 | | 2-033 | -0.020 | 2-013 | | | | | | | | N.S. | 22° 10' 1" | 22 | | 2-028 | -0.005 | 2-023 | A heavy head swell. | | | | | | | S. | 46° 50' 1" | 26 | | 2-047 | -0.020 | 2-027 | | | | | | | | N. | 44° 03' 6" | 25 | | 2-058 | -0.020 | 2-038 | | | | | | | | N.S. | 22° 09' 2" | 25 | | 2-078 | -0.020 | 2-058 | | | | | | | | N. | 44° 32' 2" | 29 | W. by N. | 2-028 | -0.005 | 2-023 | | | | | | | | N.S. | 22° 42' | 27 | | 2-078 | -0.020 | 2-058 | | | | | | | | S. | 46° 23' 5" | 30 | | 2-092 | -0.020 | 2-072 | | | | | | | | N. | 43° 29' 9" | 29 | S.W. by s.| 2-078 | -0.020 | 2-058 | | | | | | | | N.S. | 22° 01' | 29 | | 2-092 | -0.020 | 2-072 | | ## Observations of the Magnetic Force. (Continued.) | Year | Lat. | Long. | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|------|-------|-----------------|---------------------|-------------|------------|----------|----------------------------------|--------------------|---------| | 1841 | | | | | | | | | | | | Mar. 20. | -65°10' | 143°21' | S. | 46°45'7" | 22° | w.s.w. | 2·051 | -0·012 | 2·039 | Along the edge of the pack. | | | | | N. | 43°54'1" | 21° | | 2·068 | -0·012 | 2·056 | | | | | | N.S. | 22°16'5" | 21° | | 2·106 | -0·004 | 2·102 | | | | | | S. | 45°55'9" | 22° | w.N.W. | 2·081 | -0·004 | 2·077 | | | | | | N. | 43°41' | 21° | | | | | | | | | | N.S. | 21°29'5" | 21° | | | | | | | | | | wt. 5 grs. | 25°11'2" | 34° | | 2·012 | -0·002 | 2·010 | | | | | | wt. 4 grs. | 19°34'1" | 34° | | 2·045 | -0·002 | 2·043 | | | | | | wt. 3 grs. | 14°18'6" | 34° | | 2·062 | -0·002 | 2·060 | | | | | | wt. 3 grs. | 14°13' | 34° | | 2·074 | -0·002 | 2·072 | | | | | | wt. 2 grs. | 9°39' | 34° | | 2·040 | -0·002 | 2·040 | | | | | | S. | 46°53'9" | 34° | | 2·043 | -0·002 | 2·041 | | | | | | N. | 44°21'6" | 34° | | 2·039 | -0·002 | 2·037 | | | | | | N.S. | 22°00'2" | 34° | n.w. by w. | | | | | | | | | S. | 47°16'5" | 35° | | 2·019 | -0·000 | 2·019 | | | | | | N. | 44°14'5" | 34° | | 2·046 | -0·000 | 2·046 | | | | | | N.S. | 21°36'6" | 34° | | | | | | | | | | S. | 46°47'2" | 35° | | 2·050 | -0·000 | 2·050 | | | | | | N. | 43°50'1" | 35° | | 2·072 | -0·000 | 2·072 | | | | | | N.S. | 21°56' | 35° | | | | | | | | | | S. | 46°41'1" | 38° | | 2·057 | +0·003 | 2·060 | | | | | | N. | 43°42'6" | 37° | n.w. by n. | 2·079 | +0·003 | 2·081 | | | | | | N.S. | 21°58' | 36° | | | | | | | | | | S. | 46°59'2" | 35° | | 2·038 | +0·005 | 2·043 | | | | | | N. | 43°58' | 34° | n.n.w. | 2·064 | +0·005 | 2·069 | | | | | | N.S. | 22°01'1" | 34° | | | | | | | | | | S. | 47°34'3" | 40° | n.e. by e. | 2·000 | +0·003 | 2·003 | Very unsteady. | | | | | N. | 44°26'7" | 38° | | 2·033 | +0·007 | 2·040 | | | | | | N.S. | 22°20'5" | 38° | | | | | | | | | | S. | 47°30' | 40° | n.e. by n. | 2·004 | +0·007 | 2·011 | | | | | | N. | 44°43'5" | 40° | | 2·016 | +0·007 | 2·023 | | | | | | S. | 47°31'7" | 39° | | 2·002 | +0·007 | 2·009 | | | | | | N. | 44°44'4" | 39° | | 2·016 | +0·007 | 2·023 | | | | | | N.S. | 22°33'8" | 39° | | | | | | | | | | S. | 46°56'3" | 40° | | 2·041 | +0·006 | 2·047 | | | | | | N. | 44°09'5" | 40° | | 2·053 | +0·006 | 2·059 | | | | | | N.S. | 21°37'6" | 40° | n.w. | | | | | | | | | S. | 46°55'4" | 43° | | 2·042 | +0·012 | 2·054 | | | | | | N. | 44°41'5" | 40° | | 2·017 | +0·012 | 2·029 | | | | | | N.S. | 22°29'7" | 39° | | | | | | | | | | wt. 6 grs. | 31°08'5" | 40° | | 1·987 | +0·012 | 1·999 | | | | | | wt. 5 grs. | 25°28'5" | 40° | | 1·990 | +0·012 | 2·002 | | | | | | wt. 4 grs. | 19°39'7" | 40° | | 2·035 | +0·012 | 2·047 | | | | | | wt. 3 grs. | 14°07'7" | 40° | | 2·086 | +0·012 | 2·098 | | | | | | wt. 2 grs. | 9°26'2" | 40° | | 2·086 | +0·012 | 2·098 | | | | | | wt. 1 gr. | 5°10'2" | 40° | | | | | | | | | | S. | 47°16' | 43° | | 2·020 | +0·013 | 2·033 | | | | | | N. | 44°23'8" | 41° | | 2·036 | +0·013 | 2·049 | | | | | | N.S. | 22°18'5" | 39° | | | | | | | | | | N. | 45°01'5" | 43° | | | | | | | | | | N.S. | 22°56'3" | 44° | | | | | | | | | | N. | 46°33'4" | 45° | n.e. | | | | | | | | | S. | 48°37'8" | 44° | | 1·927 | +0·015 | 1·942 | | | | | | N. | 45°50'1" | 44° | n.e. | 1·941 | +0·015 | 1·956 | | | | | | N.S. | 23°03' | 44° | | 1·949 | | | | Much motion and rolling deep. A heavy sea running. ### Observations of the Magnetic Force. (Continued.) | Year | Latitude | Longitude | Method employed | Angle of deflection | Temperature | Ship's head | Intensity | Correction for ship's attraction | Corrected Intensity | Remarks | |------|----------|-----------|-----------------|---------------------|-------------|------------|----------|----------------------------------|---------------------|---------| | 1841 | April 4 | -46° 22' | S. | 48° 31'5" | 45° | N.E. by E. | 1·934 | +·011 | 1·945 | | | | | | N. | 45° 40'2" | 45° | | 1·952 | +·011 | 1·963 | | | | | | N.S. | 23° 00'9" | 45° | | 1·917 | +·012 | 1·929 | | | | | | S. | 48° 46'2" | 46° | | 1·913 | +·012 | 1·925 | | | | | | N. | 46° 15' | 47° | N.E. by E. | 1·912 | +·013 | 1·925 | | | | | | N.S. | 22° 05'9" | 47° | | 1·901 | +·013 | 1·914 | | | | | | S. | 48° 49'8" | 50° | | 1·820 | +·018 | 1·838 | | | | | | N. | 46° 25'1" | 48° | N.E. by E. | 1·884 | +·018 | 1·902 | | | | | | S. | 50° 01'4" | 60° | | 1·887 | +·018 | 1·905 | | | | | | N. | 46° 39'8" | 60° | | 1·919 | +·018 | 1·937 | | | | | | N.S. | 23° 16'8" | 59° | | 1·881 | +·018 | 1·899 | | | | | | wt. 6 grs. | 32° 58'5" | 58° | | 1·850 | +·018 | 1·868 | | | | | | wt. 5 grs. | 26° 29'7" | 58° | N.E. ½ E. | 1·885 | +·018 | 1·903 | | | | | | wt. 4 grs. | 21° 21' | 59° | | 1·870 | +·018 | 1·888 | | | | | | wt. 3 grs. | 15° 59'4" | 59° | | | | | | | | | | wt. 2 grs. | 10° 27'2" | 58° | | | | | | | | | | wt. 1 gr. | 5° 14'2" | 58° | | | | | | Running along the land. Observations of Declination made on board Her Majesty's Ship Terror, between November 15, 1840, and April 5, 1841. The Observers are distinguished by their Initials as follows:—C. Captain Crozier; P. Lieut. Phillips; Cr. Mr. Cotter, Master. | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|---------------------|------------------------|----------------|---------| | Nov 15 | -44° 24' 152° 58' | Cr. | -6° 57' s.e.by E. | -71° 40' | -4° 44' | -11° 41' | +1° 23' | -11° 38' | | | | | -44° 24' 152° 58' | Cr. | -9° 36' s.e.by E. | -4° 44' | -14° 20' | -13° 01' | +1° 23' | -11° 38' | | | | | -46° 05' 154° 18' | C. | -10° 52' s.e. | -4° 09' | -15° 01' | | | | | | | | -46° 11' 154° 18' | Cr. | -12° 57' s.e. | -4° 09' | -17° 06' | -15° 10' | +1° 23' | -13° 47' | | | | | -46° 11' 154° 18' | Cr. | -9° 48' s.e. | -4° 09' | -13° 57' | | | | | | | | -46° 24' 154° 50' | Cr. | -9° 48' s.e.by E. | -4° 49' | -14° 37' | | | | | | | | -49° 06' 160° 10' | C. | -11° 12' s.e.by E. | -5° 20' | -16° 32' | | | | | | | | -49° 14' 160° 06' | Cr. | -11° 54' s.e.by E. | -5° 20' | -17° 14' | -16° 07' | +1° 23' | -14° 44' | | | | | -49° 14' 160° 06' | Cr. | -9° 39' s.e.by E. | -5° 20' | -43° 59' | | | | | | | | -49° 40' 160° 52' | C. | -11° 23' s.e.by E. | -5° 20' | -16° 43' | | | | | | | Auckland Island. | | | | | | | | | | | | Dec. 6 | -50° 33' 166° 15' | Cr. | -21° 10' s.w.by W. | +5° 09' | -16° 01' | | | | | | | | At anchor. | Cr. | -21° 12' s.w.by W. | +5° 09' | -16° 03' | | | | | | | | | Cr. | -22° 48' s.w. | +4° 27' | -18° 21' | | | | | | | | | Cr. | -12° 11' N.E. | -5° 07' | -17° 18' | | | | | | | | | Cr. | -21° 59' s.w.by W. | +5° 09' | -16° 50' | | | | | | | | | Cr. | -21° 47' N.W.by W. | +4° 29' | -17° 18' | | | | | | | | | Cr. | -20° 32' N.W.by W. | +4° 29' | -15° 03' | | | | | | | | | C. | -19° 32' W.N.W. | +5° 07' | -14° 25' | | | | | | | | | C. | -19° 47' W.N.W. | +5° 07' | -14° 40' | | | | | | | | | C. | -20° 14' N.W.by W. | +4° 29' | -15° 45' | | | | | | | | | C. | -19° 23' N.W. | +3° 46' | -15° 37' | | | | | | | | | C. | -22° 09' W.by N. | +5° 35' | -16° 34' | | | | | | | | | C. | -21° 28' N.W.by W. | +4° 29' | -16° 59' | | | | | | | | | C. | -20° 29' N.W.by W. | +4° 48' | -15° 41' | | | | | | | | | C. | -23° 00' W. | +5° 49' | -17° 11' | | | | | | | | | C. | -22° 07' W.by N. | +5° 21' | -16° 46' | | | | | | | | | C. | -22° 05' W.by N. | +5° 35' | -16° 30' | | | | | | | | | C. | -21° 59' W. | +5° 42' | -16° 17' | | | | | | | | | C. | -22° 36' W. | +5° 50' | -16° 46' | | | | | | | | | C. | -21° 40' W. | +5° 49' | -15° 51' | | | | | | | | | C. | -20° 54' N.W.by W. | +4° 29' | -16° 25' | | | | | | | | | C. | -21° 50' W.N.W. | +5° 07' | -16° 43' | | | | | | | | | C. | -24° 23' W.by N. | +3° 35' | -18° 48' | | | | | | | | | Cr. | -20° 20' N.W.by W. | +4° 29' | -15° 51' | | | | | | | | | Cr. | -20° 29' N.W.by W. | +4° 29' | -16° 00' | | | | | | | | | Cr. | -19° 39' N.W. | +3° 46' | -15° 53' | | | | | | | | | Cr. | -21° 02' W.N.W. | +5° 07' | -15° 55' | | | | | | | | | Cr. | -21° 19' W.N.W. | +5° 07' | -16° 12' | | | | | | | | | Cr. | -22° 12' W.N.W. | +5° 07' | -17° 05' | | | | | | | | | Cr. | -21° 49' W.by N. | +5° 35' | -16° 14' | | | | | | | | | Cr. | -21° 52' W.by N. | +5° 35' | -16° 17' | | | | | | | | | Cr. | -23° 29' W. | +5° 49' | -17° 40' | | | | | | | | | C. | -12° 41' N.E. | -3° 46' | -16° 27' | | | | | | | | | C. | -13° 20' N.E.by N. | -2° 57' | -16° 17' | | | | | | | | | C. | -13° 49' N.N.E. | -1° 58' | -15° 47' | | | | | | | | | C. | -13° 18' E.S.E. | -5° 36' | -18° 54' | | | | | | | | | C. | -13° 18' S.E.by E. | -5° 09' | -18° 27' | | | | | | | | | Cr. | -13° 21' N.E. | -3° 46' | -17° 07' | | | | | | | | | Cr. | -15° 34' N.N.E. | -1° 58' | -17° 32' | | | | | | | | | Cr. | -15° 17' N.E. | -3° 46' | -19° 03' | | | | | | | | | Cr. | -11° 15' E.by S. | -5° 51' | -17° 06' | | | | | | | | | Cr. | -12° 32' E.S.E. | -5° 36' | -18° 08' | | | | | | Compass R. of Cummins, index error ascertained at Hobarton, June 841. ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|---------------------|------------------------|----------------|---------| | 1840 | Dec. 12 | -50° 32' | C. -14° 02' S.E. by E. | -73° 00' | -5° 06' | -19° 08' | | | | | | | | | C. -13° 23' S.E. by E. | | -5° 22' | -18° 45' | | | | | | | | | C. -12° 57' S.E. by E. | | -5° 22' | -18° 19' | | | | | | | | | Cr. -22° 21' W. by S. | +6° 08' | +16° 13' | | | | | | | | | Cr. -21° 49' W.S.W. | +5° 50' | -15° 59' | | | | | | | | | Cr. -22° 50' W.S.W. | +5° 50' | -17° 00' | -18° 31' | +1° 23' | -17° 08' | | | | | | | Cr. -23° 01' S.W. by W. | +5° 21' | -17° 40' | | | | | | | | | Cr. -23° 10' S.W. by W. | +5° 21' | -17° 49' | | | | | | | | | Cr. -19° 55' S.W. | +4° 38' | -15° 15' | | | | | | | | | Cr. -12° 59' E.S.E. | -5° 50' | -18° 49' | | | | | | | | | Cr. -12° 53' E.S.E. | -5° 50' | -18° 43' | | | | | | | | | Cr. -14° 11' S.S.E. | -2° 58' | -17° 09' | | | | | | | | | Cr. -21° 54' S.S.E. | -3° 06' | -25° 00' | | | | | | | | | Cr. -21° 06' S.S.E. | -3° 06' | -24° 12' | | | | | | | | | Cr. -20° 28' S. by E. | -1° 36' | -22° 04' | | | | | | | | | Cr. -23° 45' S. by E. | -1° 36' | -25° 21' | | | | | | | | | Cr. -25° 00' S. by E. | -1° 44' | -26° 44' | | | | | | | | | C. -20° 41' S. by E. ½ E. | -2° 36' | -23° 17' | -23° 21' | +1° 23' | -21° 58' | | | | | | | C. -20° 41' S. by E. ½ E. | -2° 36' | -23° 17' | | | | | | | | | Cr. -20° 21' S.S.E. | -3° 23' | -23° 44' | | | | | | | | | C. -26° 54' S.S.W. | +3° 23' | -23° 31' | | | | | | | | | C. -25° 15' S.S.W. | +3° 23' | -23° 52' | | | | | | | | | C. -26° 34' S.S.W. | +3° 23' | -23° 11' | | | | | | | | | C. -24° 05' S.S.W. ½ W. | +4° 17' | -19° 48' | | | | | | | | | Cr. -17° 24' S.E. | -6° 23' | -23° 47' | | | | | | | | | Cr. -16° 38' S.E. by E. | -7° 23' | -24° 01' | | | | | | | | | Cr. -18° 02' S.E. by S. | -5° 03' | -23° 05' | | | | | | | | | Cr. -21° 02' S.S.E. | -3° 31' | -24° 33' | | | | | | | | | Cr. -23° 36' S. | 0° 0' | -23° 36' | | | | | | | | | Cr. -24° 03' S. by W. | +1° 48' | -22° 15' | -22° 19' | +1° 23' | -20° 56' | | | | | | | Cr. -26° 39' S.S.W. | +3° 31' | -23° 08' | | | | | | | | | Cr. -26° 52' S.W. by S. | +5° 03' | -21° 49' | | | | | | | | | Cr. -28° 17' S.W. | +6° 23' | -21° 54' | | | | | | | | | Cr. -29° 01' S.W. by W. | +7° 23' | -21° 38' | | | | | | | | | Cr. -28° 11' W. by N. | +8° 11' | -20° 00' | | | | | | | | | Cr. -28° 10' W.N.W. | +7° 36' | -20° 34' | | | | | | | | | Cr. -27° 50' N.W. by W. | +6° 45' | -21° 05' | | | | | | | | | Cr. -26° 47' N.W. | +5° 41' | -21° 06' | | | | | | | | | Cr. -25° 49' N.W. by N. | +4° 26' | -21° 23' | | | | | | | | | Cr. -23° 55' N. by W. | +1° 33' | -22° 22' | -21° 43' | +1° 23' | -20° 20' | | | | | | | Cr. -21° 34' N. | 0° 0' | -21° 34' | | | | | | | | | Cr. -20° 17' N. by E. | -1° 33' | -21° 50' | | | | | | | | | Cr. -18° 32' N.N.E. | -3° 02' | -21° 34' | | | | | | | | | Cr. -18° 22' N.E. by N. | -4° 26' | -22° 48' | | | | | | | | | C. -14° 38' S.S.E. ¾ E. | -4° 53' | -19° 31' | | | | | | | | | C. -15° 17' S.S.E. ¼ E. | -4° 53' | -20° 10' | | | | | | | | | C. -25° 59' S. | 0° 0' | -25° 59' | | | | | | | | | C. -23° 38' S.S.E. | -3° 41' | -27° 19' | | | | | | | | | C. -22° 25' S.E. by S. | -5° 17' | -27° 42' | | | | | | | | | C. -23° 51' S.S.E. | -3° 41' | -27° 32' | | | | | | | | | C. -22° 00' S.E. ½ S. | -6° 00' | -28° 00' | -25° 11' | +1° 23' | -23° 48' | | | | | | | Cr. -18° 19' S.E. | -6° 41' | -25° 00' | | | | | | | | | Cr. -17° 57' S.E. | -6° 41' | -24° 38' | | | | | | | | | Cr. -21° 50' S.S.E. | -3° 41' | -25° 31' | | | | | | | | | Cr. -21° 14' S.S.E. | -3° 41' | -24° 55' | | | | | | | | | Cr. -20° 40' S.E. by S. | -5° 17' | -25° 57' | | | | | ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|-------------------------|------------|-------------------------------|----------------------|------------------------|-----------------|---------| | **1840** | | | | | | | | | | | | Dec. 29 | | | | | | | | | | | | -64° 11' | 173° 43' | C. | -27° 44' | s. ½ E. | -1° 08' | -28° 52' | | | | | | -64° 11' | 173° 43' | Cr. | -24° 39' | s. by E. | -2° 16' | -26° 55' | | | | | | -64° 26' | 173° 15' | C. | -34° 58' | s.w. | -2° 16' | -27° 25' | | | | | | -64° 26' | 173° 15' | C. | -34° 22' | s.w. | +8° 23' | -26° 35' | | | | | | -64° 26' | 173° 15' | C. | -35° 07' | s.w. ½ s. | +8° 23' | -25° 59' | | | | | | -64° 26' | 173° 15' | C. | -32° 54' | s.s.w. | +7° 30' | -27° 37' | | | | | | -64° 48' | 172° 56' | Cr. | -25° 15' | s. by E. | +4° 34' | -28° 20' | | | | | | -64° 48' | 172° 56' | Cr. | -34° 20' | s.w. | -2° 16' | -27° 31' | | | | | | -64° 48' | 172° 13' | C. | -26° 09' | s. ½ E. | +8° 23' | -25° 57' | | | | | | -65° 42' | 172° 13' | C. | -26° 13' | s. by E. | -1° 10' | -27° 19' | | | | | | -65° 42' | 172° 13' | C. | -25° 23' | s. by E. | -2° 24' | -28° 37' | | | | | | -65° 42' | 172° 13' | Cr. | -26° 26' | s. by E. | -2° 24' | -27° 47' | | | | | | -65° 42' | 172° 13' | Cr. | -26° 18' | s. by E. | -2° 24' | -28° 40' | | | | | | -65° 42' | 172° 13' | Cr. | -23° 34' | s. by E. | -2° 24' | -28° 42' | | | | | | -65° 42' | 172° 13' | Cr. | -24° 11' | s. by E. | -2° 24' | -25° 58' | | | | | | **1841** | | | | | | | | | | | | Jan. 2 | | | | | | | | | | | | -66° 24' | 170° 00' | C. | -17° 14' | E. by s. ½ s. | -11° 57' | -29° 11' | | | | | | -65° 15' | 172° 40' | Cr. | -19° 54' | S.E. | -9° 09' | -29° 03' | | | | | | -65° 15' | 172° 40' | Cr. | -20° 48' | S.E. | -9° 09' | -29° 57' | | | | | | -65° 27' | 173° 20' | Cr. | -21° 14' | E. by s. ½ s. | -11° 57' | -33° 11' | | | | | | -65° 27' | 173° 20' | Cr. | -21° 00' | E. by s. ½ s. | -11° 57' | -32° 57' | | | | | | -65° 27' | 173° 20' | C. | -17° 49' | E. ½ s. | -12° 13' | -30° 02' | | | | | | -65° 27' | 173° 20' | C. | -19° 17' | E. by s. ½ s. | -11° 57' | -31° 14' | | | | | | -65° 30' | 173° 30' | C. | -20° 04' | E. by s. ½ s. | -11° 57' | -32° 01' | | | | | | -65° 30' | 173° 30' | C. | -21° 11' | E.S.E. | -11° 44' | -32° 55' | | | | | | -65° 31' | 173° 40' | C. | -22° 19' | S.E. by E. | -10° 38' | -32° 57' | | | | | | -65° 32' | 173° 50' | C. | -21° 48' | S.E. ½ E. | -9° 53' | -31° 41' | | | | | | -65° 32' | 173° 50' | C. | -25° 56' | S.S.E. ½ E. | -6° 07' | -32° 03' | | | | | | -65° 32' | 173° 50' | C. | -22° 38' | S.E.by E.½ E. | -10° 34' | -33° 12' | | | | | | -65° 35' | 173° 52' | C. | -26° 59' | S.S.E. | -4° 41' | -31° 40' | | | | | | -65° 35' | 173° 52' | C. | -26° 54' | S. by E. | -2° 18' | -29° 12' | | | | | | -65° 35' | 173° 52' | C. | -25° 22' | S.S.E. ½ E. | -5° 45' | -31° 07' | | | | | | -65° 35' | 173° 52' | P. | -23° 56' | E. by s. ½ s. | -4° 40' | -30° 34' | | | | | | -65° 35' | 173° 52' | P. | -22° 34' | S.E. by E. | -11° 16' | -35° 12' | | | | | | -65° 28' | 173° 20' | Cr. | -18° 25' | E. by s. | -10° 02' | -32° 36' | | | | | | -65° 28' | 173° 20' | Cr. | -17° 29' | E.S.E. | -11° 25' | -29° 50' | | | | | | -65° 28' | 173° 20' | Cr. | -18° 27' | E.S.E. | -11° 04' | -28° 33' | | | | | | -65° 28' | 173° 30' | C. | -20° 09' | E.S.E. | -11° 04' | -29° 31' | | | | | | -65° 28' | 173° 30' | C. | -25° 37' | S.S.E. | -11° 04' | -31° 13' | | | | | | -65° 28' | 173° 30' | C. | -23° 12' | E.S.E. | -4° 41' | -30° 18' | | | | | | -65° 28' | 173° 30' | C. | -23° 12' | E.S.E. | -5° 57' | -36° 18' | | | | | | -65° 28' | 173° 30' | C. | -47° 46' | S.W. by W. | -12° 58' | -37° 43' | | | | | | -65° 28' | 173° 30' | C. | -22° 19' | S.E. by E. | -12° 58' | -36° 34' | | | | | | -65° 28' | 173° 30' | C. | -20° 36' | S. ¾ E. | -11° 00' | -34° 42' | | | | | | -65° 28' | 173° 30' | C. | -20° 59' | S. ¾ E. | -14° 09' | -37° 21' | | | | | | -65° 28' | 173° 30' | C. | -45° 31' | S. ¼ E. | -12° 58' | -34° 48' | | | | | | -65° 28' | 173° 30' | C. | -48° 51' | S. by W. | -14° 30' | -35° 06' | | | | | | -65° 28' | 173° 30' | C. | -43° 10' | S. | -14° 56' | -35° 55' | | | | | | -65° 28' | 173° 30' | C. | -43° 22' | S. | -1° 10' | -46° 41' | | | | | | -65° 28' | 173° 30' | C. | -44° 57' | S. | +4° 43' | -44° 08' | | | | | | -65° 28' | 173° 30' | C. | -44° 57' | S. | 0° 00' | -43° 10' | | | | | | -65° 28' | 173° 30' | C. | -44° 57' | S. | 0° 00' | -43° 22' | | | | | | -65° 28' | 173° 30' | C. | -44° 57' | S. | -8° 50' | -46° 48' | | | | | Light card of Cuxhaven; marked P. was now used. Index error ascertained at Helgoland, June 1841. MDCCCXLIII. ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|-------------|---------------------------------|----------------------|------------------------|----------------|---------| | 1841 | Jan. 11 | -71° 21' | 171° 14' Cr. | -49° 10' s. ½ w. | -85° 50' | +2° 20' -46° 50' | -46° 48' +1° 03' -45° 45' | A light east of Guernsey was noted P. was seen used. Index error determined at Hamburgh, June 1841. | | | | C. | -51° 03' s. | | | | | | | | | | | C. | -53° 04' s. by w. | | | | | | | | | | | C. | -54° 21' s. by w. | | | | | | | | | | | C. | -54° 32' s. by w. | | | | | | | | | | | C. | -53° 11' s. by w. | | | | | | | | | | | C. | -51° 22' s. | | | | | | | | | | | C. | -51° 33' s. by w. | | | | | | | | | | | C. | -50° 08' s. by w. | | | | | | | | | | | C. | -52° 01' s. by w. | | | | | | | | | | | C. | -53° 19' s. by w. | | | | | | | | | | | C. | -53° 18' s. by w. | | | | | | | | | | | C. | -53° 00' s. by w. | | | | | | | | | | | C. | -50° 53' s. by w. | | | | | | | | | | | C. | -57° 58' s.w. by s. | | | | | | | | | | | C. | -53° 25' s.w. by s. | | | | | | | | | | | C. | -27° 35' e.by s. ½ s.| | | | | | | | | | | C. | -52° 46' s.s.w. | | | | | | | | | | | C. | -54° 17' s.s.w. | | | | | | | | | | | C. | -53° 06' s. by w. | | | | | | | | | | | C. | -53° 11' s. by w. | | | | | | | | | | | C. | -25° 06' e. by s. | | | | | | | | | | | C. | -26° 50' e. by s. | | | | | | | | | | | C. | -58° 11' s.s.w. | | | | | | | | | | | C. | -58° 27' s.s.w. | | | | | | | | | | | C. | -35° 06' s.e. by e. | | | | | | | | | | | C. | -35° 46' s.e. ½ e. | | | | | | | | | | | C. | -35° 00' s.e. by e. | | | | | | | | | | | C. | -35° 00' s.e. by e. | | | | | | | | | | | C. | -34° 37' s.e. by e. | | | | | | | | | | | C. | -34° 19' s.e. by e. | | | | | | | | | | | C. | -64° 55' s.w. by s. | | | | | | | | | | | C. | -64° 17' s.w. by s. | | | | | | | | | | | C. | -65° 46' s.w. by s. | | | | | | | | | | | C. | -62° 42' s.s.w. ½ w.| | | | | | | | | | | C. | -64° 56' s.w. by s. | | | | | | | | | | | C. | -68° 00' s.w. ½ s. | | | | | | | | | | | C. | -68° 37' s.w. | | | | | | | | | | | C. | -66° 01' s.w. | | | | | | | | | | | C. | -67° 00' s.w. ½ s. | | | | | | | | | | | C. | -69° 35' s.w. | | | | | | | | | | | C. | -67° 12' s.w. ½ s. | | | | | | | | | | | C. | -67° 40' s.w. | | | | | | | | | | | C. | -67° 57' s.w. ½ s. | | | | | | | | | | | C. | -44° 51' s.s.e. ½ e.| | | | | | | | | | | C. | -44° 23' s.s.e. ½ e.| | | | | | | | | | | C. | -43° 53' s.s.e. | | | | | | | | | | | C. | -45° 36' s.s.e. | | | | | | | | | | | C. | -49° 19' s. by e. | | | | | | | | | | | C. | -54° 17' s. | | | | | | | | | | | C. | -53° 18' s. | | | | | | | | | | | P. | -48° 34' s.s.e. | | | | | | | | | | | C. | -34° 19' e. by s. | | | | | | | | | | | C. | -35° 58' e.by s. ¼ s.| | | | | | | | | | | P. | -44° 12' n.e. ½ e. | | | | | | | | | | | C. | -40° 41' n.e. by n. | | | | | | | | ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|-------------|---------------------------------|----------------------|------------------------|-----------------|---------| | 1841 | Jan. 22 | -73 46 | 171 25 Cr. | -42 16 | N.E. ½ N. | -86 50 | -54 30 | -66 46 | -66 44 | +1 03 -65 41 | | | | -73 46 | 171 25 Cr. | -43 41 | N.E. ½ N. | | -24 30 | -68 11 | | | | | | -73 46 | 171 25 Cr. | -36 51 | E.N.E. | | -29 58 | -66 49 | | | | | | -73 46 | 171 25 Cr. | -36 16 | E.N.E. | | -29 58 | -66 14 | | | | | | -73 46 | 171 25 Cr. | -36 32 | E. by N. | | -32 03 | -68 35 | | | | | | -73 46 | 171 25 Cr. | -36 26 | E. by N. | | -32 03 | -68 29 | | | | | | -73 46 | 171 35 Cr. | -36 14 | E. | | -31 04 | -67 18 | | | | | | -73 46 | 171 35 Cr. | -36 12 | E. | | -31 04 | -67 16 | | | | | | -73 46 | 171 35 Cr. | -36 50 | E. | | -31 04 | -67 54 | | | | | | -73 46 | 171 35 Cr. | -35 47 | E. by S. | -86 40 | 0 0 | -62 48 | -65 15 | +1 03 -64 12 | | | | -73 59 | 171 40 C. | -62 48 | S. | | 0 0 | -63 52 | | | | | | -73 59 | 171 40 C. | -63 52 | S. | | 0 0 | -62 41 | | | | | | -74 03 | 171 40 C. | -62 41 | S. | | 0 0 | -63 47 | | | | | | -74 03 | 171 40 C. | -63 47 | S. | | -27 31 | -68 04 | | | | | | -74 04 | 173 09 C. | -40 33 | E. by s. | | -27 31 | -68 18 | | | | | | -74 04 | 172 43 C. | -40 47 | E. by s. | | -27 31 | -66 18 | -66 07 | +1 03 -65 04 | | | | -74 04 | 172 43 Cr. | -38 47 | E. by s. | -86 20 | 0 0 | -62 02 | | | | | | -73 55 | 172 46 C. | -62 02 | S. | | -27 31 | -65 33 | | | | | | -73 59 | 171 32 Cr. | -38 22 | E. by s. | | +13 46 | -63 27 | | | | | | -74 24 | 168 28 C. | -77 13 | S.S.W. | | +13 46 | -67 27 | | | | | | -74 24 | 168 28 C. | -81 13 | S.S.W. | | +13 46 | -66 38 | | | | | | -74 24 | 168 28 Cr. | -80 24 | S.S.W. | -87 10 | -34 13 | -73 41 | | | | | | -74 28 | 168 46 Cr. | -39 28 | E.S.E. | | -34 13 | -72 52 | | | | | | -74 28 | 168 46 Cr. | -38 39 | E.S.E. | | -34 13 | -74 10 | | | | | | -74 50 | 168 45 C. | -43 23 | E. by s. | | -46 49 | -90 12 | | | | | | -75 37 | 168 28 C. | -102 27 | S. by w. | -87 40 | -8 23 | -94 04 | | | | | | -74 45 | 168 48 Cr. | -33 53 | E. ½ S. | | -47 08 | -81 01 | | | | | | -75 40 | 168 28 C. | -53 33 | E.S.E. | | -36 33 | -90 06 | | | | | | -75 40 | 168 28 C. | -56 14 | E.S.E. | | -36 33 | -92 47 | | | | | | -75 40 | 168 28 C. | -60 19 | E.S.E. | -87 20 | -36 33 | -96 52 | | | | | | -75 40 | 168 28 Cr. | -55 50 | E.S.E. | | -36 33 | -92 23 | | | | | | -75 40 | 168 28 Cr. | -56 52 | E.S.E. | | -36 33 | -93 25 | | | | | | -75 40 | 168 28 Cr. | -58 39 | E.S.E. | | -36 33 | -95 12 | | | | | | -75 58 | 168 50 C. | -72 06 | S.E. ½ E. | -87 60 | -28 16 | -100 22 | | | | | | -75 58 | 168 50 C. | -73 11 | S.E. ½ E. | | -28 16 | -101 27 | | | | | | -76 47 | 169 26 C. | -72 17 | E. ¾ S. | -87 10 | -36 36 | -108 53 | | | | | | -76 47 | 169 26 C. | -70 45 | E. by s. | | -36 38 | -107 23 | | | | | | -77 17 | 171 38 C. | -81 31 | E. ½ S. | -87 00 | -34 42 | -116 13 | | | | | | -77 22 | 172 00 C. | -80 29 | S. ½ S. | | -34 42 | -115 01 | | | | | | -77 30 | 172 20 C. | -119 58 | N. ¾ W. | | +4 46 | -115 12 | | | | | | -77 17 | 172 20 C. | -116 46 | N. ¼ W. | | +1 35 | -115 11 | | | | | | -77 47 | 176 23 P. | -98 39 | N. by E. | | -6 21 | -105 00 | | | | | | -77 47 | 176 23 P. | -94 04 | N. by E. | | -6 21 | -100 25 | | | | | | -77 47 | 176 14 Cr. | -100 48 | N. | -87 00 | 0 0 | -100 48 | | | | | | -77 46 | 176 38 C. | -123 50 | N.W. by N. | | +18 23 | -105 27 | | | | | | -77 46 | 176 00 C. | -110 43 | N. by W. | | +6 21 | -104 22 | | | | | | -77 06 | 187 30 Cr. | -65 19 | N.E. | | -17 26 | -82 45 | | | | | | -77 06 | 187 42 C. | -64 40 | N.E. | | -17 26 | -82 06 | | | | | | -77 03 | 189 03 C. | -76 06 | S.E. by s. | -86 00 | -14 14 | -90 20 | | | | | | -77 03 | 189 03 C. | -74 36 | S.E. by s. | | -14 14 | -88 50 | | | | | | -77 45 | 187 08 C. | -74 47 | S. 62° E. | -85 50 | -19 48 | -86 59 | | | | | | -77 45 | 187 08 C. | -75 23 | S.E. by E. | | -21 00 | -95 47 | | | | | | -77 45 | 187 08 C. | -76 56 | S.E. by E. | | -20 29 | -95 52 | | | | | | -77 45 | 187 08 C. | -77 48 | S. 50° E. | | -18 56 | -96 44 | | | --- **2 G 2** ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|----------------------|------------------------|----------------|---------| | 1841 | Feb. 2 | P | -75° 39' E.by s. ½ S.| -85° 50 | -23° 22' -99° 01 | -96° 24'+1° 03-95° 21 | | | | | | | | P | -73° 43' E.by s. ½ E.| -85° 50 | -23° 22' -97° 05 | | | | | | | | | C | -74° 56' S.E.by E. | -85° 50 | -18° 56' -93° 52 | | | | | | | | | C | -74° 57' S.E.by E. | -85° 50 | -20° 29' -95° 26 | | | | | | | | | C | -115° 08' N.74° W. | -85° 50 | +23° 07' -92° 01 | | | | | | | | | C | -118° 10' N.80° W. | -85° 50 | +24° 00' -94° 10 | | | | | | | | | C | -77° 37' N.56° E. | -85° 50 | -19° 50' -97° 27 | | | | | | | | | C | -76° 48' S.56° E. | -85° 50 | -20° 29' -97° 17 | | | | | | | | | C | -75° 16' E.S.E. | -85° 50 | -22° 41' -97° 57 | | | | | | | | | C | -74° 39' E.S.E. | -85° 50 | -22° 41' -97° 20 | | | | | | | | | C | -77° 31' S.83° E. | -85° 50 | -25° 15' -102° 46' | | | | | | | | | C | -76° 06' S.75° E. | -85° 50 | -21° 30' -97° 36 | | | | | | | | | C.R. | -73° 42' E.by S. | -86° 00 | -25° 04' -98° 46 | | | | | | | | | C | -119° 49' S.74° W. | -86° 00 | +21° 49' -98° 00 | | | | | | | | | C | -117° 43' S.67° W. | -86° 00 | +23° 39' -94° 04 | | | | | | | | | C | -77° 32' S.10° E. | -86° 00 | -4° 31' -82° 03' | | | | | | | | | C | -59° 49' N.E.by E.½ E.| -86° 00 | -20° 10' -79° 59 | | | | | | | | | C.R. | -62° 37' E.N.E. | -86° 00 | -21° 18' -83° 55 | | | | | | | | | C | -62° 30' E.by N. | -86° 00 | -22° 48' -85° 18 | | | | | | | | | C | -53° 34' E.by N.¼ N. | -86° 00 | -21° 40' -85° 14 | | | | | | | | | C.R. | -61° 20' E.N.E. | -86° 00 | -21° 18' -82° 38 | | | | | | | | | C | -96° 17' S.S.W.½ W. | -85° 40 | +11° 12' -85° 05 | | | | | | | | | C | -88° 25' S.by W. | -85° 40 | +4° 31' -83° 54 | | | | | | | | | C | -83° 24' S.¼ E. | -85° 40 | -1° 05' -84° 29 | | | | | | | | | C | -65° 46' N.E.by E.½ E.| -85° 40 | -20° 10' -85° 56 | | | | | | | | | P | -62° 30' E.½ N. | -85° 40 | -23° 06' -85° 36 | | | | | | | | | P | -64° 04' E.¾ N. | -85° 40 | -22° 57' -87° 01 | | | | | | | | | C.R. | -93° 11' S.S.W. | -85° 40 | +9° 03' -82° 08 | | | | | | | | | C | -88° 27' S.¾ W. | -86° 00 | +3° 42' -84° 45 | | | | | | | | | C | -86° 19' S.½ W. | -86° 00 | +2° 28' -83° 51 | | | | | | | | | C | -61° 44' E.N.E. | -86° 00 | -23° 10' -84° 54 | | | | | | | | | C | -62° 49' E.by N.½ N. | -86° 00 | -24° 00' -86° 49 | | | | | | | | | C | -82° 24' S.¾ E. | -86° 00 | -3° 42' -86° 06 | | | | | | | | | C | -93° 19' S.by W.¾ W. | -86° 00 | +8° 35' -84° 44 | | | | | | | | | P | -87° 16' S.½ W. | -86° 00 | +2° 28' -84° 48 | | | | | | | | | C.R. | -84° 11' S. | -86° 00 | 0° 0' -84° 11 | | | | | | | | | C.R. | -87° 13' S.by W.½ W. | -86° 00 | +7° 22' -79° 51 | | | | | | | | | C.R. | -95° 43' S.by W.½ W. | -86° 00 | +7° 22' -88° 21 | | | | | | | | | C | -61° 53' E. | -86° 00 | 25° 25' -87° 18 | | | | | | | | | C | -63° 01' E. | -86° 00 | -25° 25' -88° 26 | | | | | | | | | C | -63° 08' E.¼ N. | -86° 00 | -25° 06' -88° 14 | | | | | | | | | C.R. | -92° 37' S.by W.¾ W. | -86° 00 | +8° 35' -84° 02 | | | | | | | | | C | -72° 58' S.E.by E.½ E.| -86° 00 | -22° 30' -95° 28 | | | | | | | | | C | -70° 33' E.S.E. | -86° 00 | -23° 39' -94° 12 | | | | | | | | | C | -77° 19' S.E.¾ S. | -86° 00 | -15° 12' -92° 31 | | | | | | | | | C | -75° 44' S.E. | -86° 00 | -18° 07' -93° 51 | | | | | | | | | C.R. | -76° 11' S.E. | -86° 00 | -18° 07' -94° 18 | | | | | | | | | C | -65° 18' E.½ S. | -86° 00 | -25° 15' -90° 33' | | | | | | | | | C | -69° 25' E.¼ N. | -86° 00 | -25° 16' -94° 41 | | | | | | | | | C | -69° 20' E.½ N. | -86° 00 | -25° 07' -94° 27 | | | | | | | | | C | -69° 39' E.½ N. | -86° 00 | -25° 07' -94° 46 | | | | | | | | | C | -70° 52' E.by N.¼ N. | -86° 00 | -23° 35' -94° 27 | | | | | | | | | C.R. | -72° 06' S.E.by E.¾ E.| -86° 00 | -23° 35' -94° 27 | | | | | | | | | C | -68° 35' E. | -86° 00 | -23° 04' -95° 10 | | | | | | | | | C | -72° 52' E.N.E. | -86° 00 | -25° 25' -94° 00 | | | | | | | | | C.R. | -74° 04' N.E.by E.½ E.| -86° 00 | -23° 10' -96° 02 | | | | | | | | | C.R. | -74° 04' N.E.by E.½ E.| -86° 00 | -21° 56' -96° 00 | | | | | | ### Observations of Declination (Continued) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|----------------------|------------------------|----------------|---------| | 1841 | Feb. 9 | C. | -108° 41' | S.W. by S. | +14° 14' | 9° 27' | | | | | | | | C. | -106° 37' | S.W. by S. | +14° 14' | 9° 23' | | | | | | | | C. | -107° 42' | S.S.W. by W. | +12° 01' | 9° 41' | | | | | | | | P. | -110° 56' | S.S.W. by W. | +14° 14' | 9° 31' | | | | | | | | C. | -114° 10' | S.W. by W. | +12° 01' | 9° 55' | | | | | | | | P. | -111° 10' | S.W. | +15° 12' | 9° 58' | | | | | | | | C. | -101° 52' | S.S.W. | +18° 07' | 9° 23' | | | | | | | | C. | -82° 26' | S.S.E. by E. | +13° 01' | 8° 51' | | | | | | | | C. | -67° 30' | S.E. | +13° 01' | 9° 05' | | | | | | | | C. | -65° 14' | E. by S. | +22° 47' | 10° 13' | | | | | | | | C. | -70° 38' | E. by S. | +32° 02' | 9° 32' | | | | | | | | C. | -74° 30' | E. by N. | +46° 49' | 11° 03' | | | | | | | | C. | -82° 25' | N.E. by E. | +46° 49' | 11° 27' | | | | | | | | P. | -73° 22' | E. by S. | +46° 47' | 11° 17' | | | | | | | | C. | -66° 43' | E. by S. | +37° 36' | 12° 01' | | | | | | | | C. | -72° 58' | E. by S. | +46° 47' | 11° 09' | | | | | | | | C. | -144° 55' | W.by N. by N. | +46° 47' | 11° 17' | | | | | | | | C. | -131° 51' | N.W. | +46° 47' | 11° 17' | | | | | | | | C. | -140° 50' | N.W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -51° 37' | E. | +46° 47' | 11° 17' | | | | | | | | C. | -56° 46' | E. by S. | +46° 47' | 11° 17' | | | | | | | | C. | -129° 44' | W.N.W. | +46° 47' | 11° 17' | | | | | | | | C. | -100° 16' | S. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -110° 40' | S.W. | +46° 47' | 11° 17' | | | | | | | | C. | -109° 33' | S.W. | +46° 47' | 11° 17' | | | | | | | | C. | -110° 11' | S.W. | +46° 47' | 11° 17' | | | | | | | | C. | -109° 24' | S.W. | +46° 47' | 11° 17' | | | | | | | | C. | -72° 08' | W. by N. | +46° 47' | 11° 17' | | | | | | | | C. | -19° 00' | E.N.E. | +46° 47' | 11° 17' | | | | | | | | C. | -21° 22' | E. by N. | +46° 47' | 11° 17' | | | | | | | | C. | -45° 30' | S. by E. | +46° 47' | 11° 17' | | | | | | | | C. | -59° 52' | W.by N. by N. | +46° 47' | 11° 17' | | | | | | | | C. | -57° 07' | N.W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -48° 07' | N.W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -46° 51' | N.W. | +46° 47' | 11° 17' | | | | | | | | C. | -51° 55' | N.W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -50° 19' | N.W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -46° 14' | S.by W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -53° 54' | W.by S. | +46° 47' | 11° 17' | | | | | | | | C. | -53° 23' | W.by S. by S. | +46° 47' | 11° 17' | | | | | | | | C. | -55° 05' | W.by S. | +46° 47' | 11° 17' | | | | | | | | C. | -51° 31' | W.by S. by S. | +46° 47' | 11° 17' | | | | | | | | C. | -47° 25' | S.by W. | +46° 47' | 11° 17' | | | | | | | | C. | -39° 10' | S.by E. by E. | +46° 47' | 11° 17' | | | | | | | | C. | -45° 52' | W.by N. by N. | +46° 47' | 11° 17' | | | | | | | | C. | -45° 17' | N.W.byW.byW. | +46° 47' | 11° 17' | | | | | | | | C. | -46° 45' | W.N.W. | +46° 47' | 11° 17' | | | | | | | | C. | -46° 49' | W.by N. | +46° 47' | 11° 17' | | | | | | | | C. | -28° 22' | S.by W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -26° 58' | S.by W. | +46° 47' | 11° 17' | | | | | | | | C. | -32° 43' | S.by W. by W. | +46° 47' | 11° 17' | | | | | | | | C. | -32° 48' | S.S.W. | +46° 47' | 11° 17' | | | | | --- **Remarks:** ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|----------------------|-------------------------|----------------|---------| | 1841 | | | | | | | | | | | | | Lat. | Long. | | | | | | | | | | Mar. 6 | -65 50 | 164 40 | C. | -37° 12' s.s.w. ½ W. | | + 0° 36' | -29° 36' | | | | | | -65 50 | 164 40 | C. | -35° 02 s.s.w. | | + 6° 12' | -28° 50' | | | | | | -65 50 | 164 40 | C. | -34° 22 s.s.w. | | + 6° 12' | -28° 10' | | | | | | -65 50 | 164 40 | C. | -33° 23 s.by w. ½ W. | | + 4° 40' | -28° 43' | | | | | | -65 50 | 164 40 | C. | -38° 53 s.w. by s. | | + 8° 59' | -29° 54' | | | | | | -65 50 | 164 40 | C. | -39° 02 s.w. ½ S. | | +10° 13' | -29° 08' | | | | | | -65 50 | 164 40 | Cr. | -38° 29 s.s.w. | | +11° 27' | -27° 02' | | | | | | -65 47 | 164 30 | C. | -40° 08 W. ¼ N. | | +15° 23' | -24° 35' | | | | | | -65 50 | 164 37 | Cr. | -42° 20 W. ¼ S. | | +15° 35' | -26° 45' | | | | | | -65 34 | 162 08 | C. | -29° 08 N.by w. ½ W. | | + 4° 08' | -25° 00' | | | | | | -65 34 | 162 08 | C. | -27° 42 N.by w. ½ W. | | + 4° 08' | -23° 34' | | | | | | -65 34 | 162 08 | C. | -29° 19 N.N.W. | | + 5° 31' | -23° 48' | | | | | | -65 34 | 162 08 | C. | -36° 28 N.W. | | +10° 19' | -24° 50' | | | | | | -65 34 | 162 08 | C. | -16° 26 S.E.by E. | | -12° 58' | -29° 26' | | | | | | -65 34 | 162 08 | Cr. | -25° 28 N.by w. ½ W. | | + 4° 08' | -26° 08' | | | | | | -64 44 | 162 20 | C. | -25° 24 N.by e. ½ E. | | - 3° 49' | -29° 13' | | | | | | -64 44 | 162 20 | C. | -23° 05 N.N.E. | | - 5° 07' | -28° 12' | | | | | | -64 44 | 162 20 | C. | -20° 49 N.N.E. ½ E. | | - 6° 18' | -27° 07' | | | | | | -64 44 | 162 20 | C. | -19° 40 N.E. ½ N. | | - 8° 31' | -28° 11' | | | | | | -64 44 | 162 20 | Cr. | -18° 01 N.E. ½ E. | | -10° 32' | -28° 33' | | | | | | -64 20 | 164 34 | C. | -30° 53 s.by w. | | + 2° 43' | -28° 10' | | | | | | -64 20 | 164 34 | C. | -31° 16 s.by w. ½ W. | | + 3° 25' | -27° 51' | | | | | | -64 23 | 164 15 | C. | -33° 23 s.s.w. ½ W. | | + 6° 48' | -26° 35' | | | | | | -64 23 | 164 15 | C. | -32° 17 s.s.w. ¼ W. | | + 6° 10' | -26° 07' | | | | | | -64 22 | 164 30 | Cr. | -31° 51 s.by w. | | + 2° 43' | -29° 08' | | | | | | -64 10 | 163 00 | C. | -34° 24 N.W. ½ W. | | +10° 32' | -23° 52' | | | | | | -64 10 | 163 00 | C. | -32° 34 N.W. ½ W. | | +10° 32' | -22° 02' | | | | | | -64 18 | 163 15 | Cr. | -33° 14 N.W.by w. | | +11° 30' | -21° 44' | | | | | | -64 18 | 163 15 | Cr. | -32° 42 N.W. | | + 9° 34' | -23° 08' | | | | | | -64 00 | 163 00 | C. | -33° 44 N.N.W. ½ W. | | + 6° 17' | -27° 27' | | | | | | -64 00 | 163 00 | C. | -35° 55 S.W. ¾ S. | | + 9° 06' | -26° 49' | | | | | | -64 00 | 163 00 | C. | -35° 23 S.W. ½ S. | | + 9° 06' | -24° 17' | | | | | | -64 04 | 162 40 | C. | -36° 53 S.W.by w. | | +12° 00' | -24° 53' | | | | | | -64 04 | 162 40 | C. | -37° 54 S.W.by w. ½ W. | | +12° 34' | -25° 20' | | | | | | -64 04 | 162 40 | C. | -38° 41 W.S.W. | | +13° 09' | -25° 32' | | | | | | -64 04 | 160 53 | C. | -34° 41 W. ½ S. | | +13° 51' | -20° 50' | | | | | | -64 04 | 160 53 | C. | -34° 28 W.by s. | | +13° 48' | -20° 40' | | | | | | -64 07 | 161 20 | C. | -29° 30 S.W.by w. ½ W. | | + 6° 48' | -22° 42' | | | | | | -64 07 | 161 20 | C. | -37° 55 S.W.by w. | | +12° 00' | -25° 55' | | | | | | -62 49 | 157 00 | C. | -22° 39 S.S.E. | | - 5° 24' | -28° 03' | | | | | | -62 49 | 157 00 | C. | -22° 32 S.S.E. | | - 5° 24' | -27° 56' | | | | | | -62 49 | 157 00 | C. | -21° 53 s.by e. ½ E. | | - 4° 00' | -25° 53' | | | | | | -62 49 | 157 00 | C. | -22° 42 s.by e. ¼ E. | | - 4° 42' | -27° 24' | | | | | | -62 49 | 157 00 | Cr. | -24° 05 S.S.E. | | - 5° 24' | -29° 29' | | | | | | -62 55 | 157 07 | C. | -25° 07 S.S.E. | | - 5° 24' | -30° 31' | | | | | | -62 55 | 157 07 | Cr. | -22° 42 S.S.E. | | - 5° 24' | -28° 06' | | | | | | -63 50 | 151 35 | C. | -21° 06 s.by w. | | + 3° 06' | -18° 00' | | | | | | -63 50 | 151 35 | C. | -17° 35 S. ½ E. | | - 1° 30' | -18° 05' | | | | | | -63 50 | 151 35 | C. | -14° 57 s.by e. ½ E. | | - 4° 30' | -19° 27' | | | | | | -63 50 | 151 35 | C. | -14° 47 S.S.E. | | - 6° 12' | -20° 59' | | | | | | -63 50 | 151 35 | C. | -17° 05 s.by e. ¼ E. | | - 3° 50' | -20° 55' | | | | | | -63 50 | 151 35 | C. | -21° 27 S. ½ W. | | + 1° 30' | -19° 57' | | | | | | -63 50 | 151 35 | C. | -29° 36 S.W. | | +11° 27' | -18° 09' | | | | | | -63 50 | 151 35 | C. | -22° 16 S. ½ W. | | + 1° 30' | -20° 46' | | | | | | -63 50 | 151 35 | Cr. | -19° 32 S. ½ E. | | - 1° 30' | -21° 02' | | | | | | -63 50 | 151 35 | Cr. | -15° 30 S.S.E. | | - 6° 12' | -21° 42' | | | | *Card R substituted.* ## Observations of Declination. (Continued.) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|--------------------------|------------|---------------------------------|----------------------|------------------------|-----------------|---------| | 1841 | | | | | | | | | | | | | Lat. | Long. | Declination | Direction | Inclination| Correction | Corrected | Correction | True Declination | Remarks | | | | | | | | | Declination | | | | | Mar. 19 | -64 15 | 149 00 | C. | -24 28 | S.W. | +11 11 | -13 17 | +1 23 | -13 59 | | | | -64 15 | 149 00 | C. | -24 03 | S.S.W. | +9 05 | -14 58 | +1 23 | -13 59 | | | | -64 15 | 149 00 | C. | -17 37 | S.S.W. | +6 45 | -10 52 | +1 23 | -13 59 | | | | -64 15 | 149 00 | C. | -23 31 | S.S.W. | +8 19 | -15 12 | +1 23 | -13 59 | | | | -64 15 | 149 00 | Cr. | -28 00 | S.W. by s. | +9 50 | -18 10 | +1 23 | -13 59 | | | | -64 15 | 149 00 | Cr. | -25 51 | S.W. by s. | +9 50 | -16 01 | +1 23 | -13 59 | | | | -64 27 | 148 12 | C. | -28 51 | S.W. by s. | +9 50 | -19 01 | +1 23 | -13 59 | | | | -64 05 | 140 00 | C. | -21 49 | W. 1/2 N. | +16 13 | -5 36 | +1 23 | -13 59 | | | | -64 05 | 140 00 | C. | -21 13 | W. by N. | +16 01 | -5 12 | +1 23 | -13 59 | | | | -63 10 | 139 30 | C. | -17 14 | N.W. 1/2 W.| +12 25 | -4 49 | +1 23 | -13 59 | | | | -63 10 | 139 30 | C. | -15 50 | N.W. 1/2 N.| +10 02 | -5 48 | +1 23 | -13 59 | | | | -63 10 | 139 30 | C. | -18 22 | N.W. 1/2 W.| +11 51 | -6 31 | +1 23 | -13 59 | | | | -63 06 | 139 40 | C. | -16 01 | N.W. by w. | +13 34 | -2 27 | +1 23 | -13 59 | | | | -63 06 | 139 40 | C. | -17 47 | N.W. 1/2 W.| +12 25 | -5 22 | +1 23 | -13 59 | | | | -63 06 | 139 40 | C. | -15 36 | N.W. 1/2 W.| +12 25 | -3 11 | +1 23 | -13 59 | | | | -62 25 | 136 30 | C. | -11 46 | N.W. by n. | +18 24 | -3 22 | +1 23 | -13 59 | | | | -62 25 | 136 30 | C. | -12 04 | N.W. 1/2 W.| +11 20 | -0 44 | +1 23 | -13 59 | | | | -62 05 | 136 00 | C. | -13 15 | W.by N. 1/4 N.| +15 02 | +1 47 | +0 12 | +1 23 | +1 35 | | | -62 05 | 136 00 | C. | -14 54 | W. by N. | +15 17 | +0 23 | +1 23 | -13 59 | | | | -62 05 | 136 00 | C. | -11 20 | W.N.W. | +14 16 | +2 56 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -2 53 | N.W. 1/2 N.| +8 43 | +5 50 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -0 35 | N.W. 1/2 N.| +8 43 | +8 08 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -3 15 | N.W. 1/2 N.| +8 43 | +5 28 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -4 53 | N.W. 1/2 W.| +10 48 | +5 55 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -4 12 | N.W. | +9 48 | +5 36 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -2 17 | N.W. 1/2 N.| +8 43 | +6 26 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -2 24 | N.W. 1/2 N.| +8 43 | +6 19 | +1 23 | -13 59 | | | | -60 23 | 131 38 | C. | -2 34 | N.W. 1/2 N.| +9 15 | +6 41 | +1 23 | -13 59 | | | | -60 33 | 131 37 | Cr. | -0 41 | N.W. | +9 48 | +9 07 | +1 23 | -13 59 | | | | -60 33 | 131 37 | Cr. | -1 58 | N.W. | +9 48 | +7 50 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -5 54 | W.by N. 1/2 N.| +9 48 | +8 14 | | | -60 20 | 131 30 | C. | -8 02 | N. 1/2 W. | +13 06 | +7 12 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -3 25 | N.W.byW.1/2W.| +1 15 | +9 17 | | | -60 20 | 131 30 | C. | -8 30 | N. 1/2 W. | +12 05 | +8 40 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -8 05 | N. 1/2 W. | +1 53 | +10 23 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -1 55 | N.W.byW.1/4W.| +1 53 | +9 58 | | | -60 20 | 131 30 | C. | -12 22 | N.E.E. | +11 48 | +9 53 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -19 22 | N.E.by N. | -5 07 | +7 15 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -13 35 | N.N.E. | +12 05 | +7 07 | +1 23 | -13 59 | | | | -60 20 | 131 30 | C. | -4 58 | N.W.byW.1/2W.| +8 15 | +7 58 | | | -59 24 | 129 46 | C. | -0 17 | N.W. 1/2 N.| +1 49 | +9 36 | +1 23 | -13 59 | | | | -59 12 | 129 40 | C. | +7 47 | N. 3/4 W. | +3 03 | +7 32 | +1 23 | -13 59 | | | | -59 12 | 129 40 | C. | +4 29 | N.by W. 1/2 W.| +5 32 | +8 06 | | | -59 12 | 129 40 | C. | +2 34 | N.N.W. 1/2 W.| +6 41 | +7 49 | | | -59 12 | 129 40 | C. | +1 08 | N.N.W. 3/4 W.| +4 58 | +10 03 | | | -59 12 | 129 40 | C. | +5 05 | N.N.W. | 0 0 | +10 02 | +1 23 | -13 59 | | | | -58 00 | 129 45 | C. | +10 02 | N. | +11 30 | +6 35 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | -4 55 | W.by S. 3/4 S.| +11 48 | +8 07 | | | -57 22 | 127 40 | C. | -3 41 | W.by S. | +11 49 | +9 49 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | -2 00 | W. 1/2 S. | -11 04 | +3 20 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | +14 24 | E.by N. 3/4 N.| +11 47 | +9 28 | | | -57 22 | 127 40 | C. | -2 19 | W. 1/2 N. | +11 47 | +11 03 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | -0 44 | N. 1/2 N. | -8 58 | +3 29 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | +12 27 | N.E. 1/2 E.| -8 58 | +5 58 | +1 23 | -13 59 | | | | -57 22 | 127 40 | C. | +14 56 | N.E. 1/2 E.| ### Observations of Declination (Continued) | Year | Position | Observers | Declination observed | Direction of ship's head | Inclination | Correction for ship's attraction | Corrected Declination | Correction for index error | True Declination | Remarks | |------|----------|-----------|----------------------|-------------------------|------------|---------------------------------|-----------------------|------------------------|----------------|---------| | 1841 | Mar. 29 | C. | +15° 58' | N.E.by E.½ E. | | | | | | | | | | C. | +10° 23' | N.E.½ E. | | | | | | | | | | C. | +14° 24' | N.E. | | | | | | | | | | Cr. | +11° 40' | E.by N. | -81° 15' | | | | | | | | | Cr. | +11° 35' | N.E.by N. | | | | | | | | | | Cr. | +9° 11' | N.E.by N. | | | | | | | | | | C. | +8° 56' | N.E.by E.¾ E. | | | | | | | | | | C. | +7° 38' | N.E.by E.¾ E. | | | | | | | | | | C. | +1° 47' | N.E. | | | | | | | | | | C. | +4° 15' | N.E.½ N. | | | | | | | | | | C. | +5° 18' | N.E.½ N. | | | | | | | | | | C. | +8° 28' | N.E. | -80° 20' | | | | | | | | | C. | +2° 52' | N.E.by N. | | | | | | | | | | Cr. | +7° 20' | N.by E.¾ E. | | | | | | | | | | C. | +2° 37' | N.E.½ E. | | | | | | | | | | C. | +8° 00' | N.E.by E. | -80° 20' | | | | | | | | | C. | +2° 37' | N.N.E.½ E. | | | | | | | | | | C. | -0° 04' | N.E.½ E. | | | | | | | | | | C. | +3° 45' | N.E.¼ E. | | | | | | | | | | C. | +4° 43' | N.E.by N. | | | | | | | | | | C. | +3° 24' | N.N.E.¾ E. | | | | | | | | | | C. | +0° 32' | N.by E.¾ E. | -80° 20' | | | | | | | | | C. | +2° 57' | N.¾ E. | | | | | | | | | | Cr. | +1° 47' | N.N.E. | | | | | | | | | | Cr. | +2° 46' | N.E.½ N. | | | | | | | | | | C. | +4° 03' | E.by N.½ N. | | | | | | | | | | C. | +6° 12' | E.N.E. | | | | | | | | | | C. | +2° 07' | E.by N.½ N. | | | | | | | | | | C. | +2° 25' | E.½ N. | | | | | | | | | | C. | +2° 07' | E.½ N. | | | | | | | | | | C. | +6° 00' | E.½ N. | -79° 15' | | | | | | | | | Cr. | +5° 19' | E.by N. | | | | | | | | | | Cr. | +2° 53' | E.by N. | | | | | | | | | | Cr. | +4° 27' | E.by N. | | | | | | | | | | Cr. | +1° 34' | E. | | | | | | | | | | Cr. | +3° 38' | E. | | | | | | | | | | C. | -0° 30' | N.N.E.¾ E. | | | | | | | | | | C. | -0° 46' | N.E.½ E. | | | | | | | | | | C. | -0° 44' | N.N.E.¾ E. | | | | | | | | | | C. | -1° 52' | N.by E.¼ E. | -79° 00' | | | | | | | | | C. | -1° 18' | N.by E.½ E. | | | | | | | | | | C. | -2° 56' | N.by E.½ E. | | | | | | | | | | C. | -1° 47' | N.N.E. | | | | | | | | | | C. | -4° 08' | N.N.E. | | | | | | | | | | Cr. | -5° 35' | N.by E.½ E. | -77° 30' | | | | | | | | | C. | -4° 12' | N.by E.¼ E. | | | | | | | | | | C. | -2° 00' | N.E. | | | | | | | | | | Cr. | -7° 44' | N.E. | -73° 00' | | | | | | | | | C. | -7° 22' | N.E. | | | | | | | | | | C. | -7° 12' | N.E.by E. | | | | | | | | | | C. | -8° 16' | N.E. | | | | | | | | | | C. | -7° 21' | N.E.¾ E. | | | | | | | | | | Cr. | -1° 23' | E.N.E. | | | | | | | | | | Cr. | -2° 22' | S.E. | | | | | | | | | | Cr. | -6° 19' | S.S.E.½ E. | | | | | | | | | | C. | -7° 16' | N.E.½ E. | | | | | | | | | | C. | -5° 01' | N.E.½ E. | | | | | | | | | | C. | -5° 57' | N.E.¼ E. | | | | | | | General Table of the Declinations observed on board Her Majesty's Ships Erebus and Terror, between November 1840 and April 1841. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -60 20 | 131 30 | Terror. | 10 | +10 23 | | -59 03 | 129 33 | Terror. | 7 | +10 07 | | -57 21 | 127 45 | Erebus. | 10 | +8 47 | | -57 22 | 127 40 | Terror. | 8 | +8 37 | | -58 54 | 129 38 | Erebus. | 11 | +8 32 | | -60 20 | 131 21 | Erebus. | 8 | +8 18 | | -60 25 | 131 38 | Terror. | 11 | +8 15 | | -60 25 | 131 37 | Erebus. | 10 | +8 09 | | -60 20 | 131 22 | Erebus. | 7 | +7 38 | | -56 14 | 130 44 | Erebus. | 8 | +5 46 | | -56 39 | 129 45 | Terror. | 7 | +5 21 | + 15° to + 5°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -50 32 | 166 12 | Erebus. | 6 | -17 44 | | -52 33 | 169 09 | Erebus. | 2 | -17 52 | | -63 50 | 151 35 | Terror. | 10 | -18 31 | | -54 14 | 169 06 | Erebus. | 5 | -18 44 | | -63 50 | 151 48 | Erebus. | 6 | -18 59 | | -63 52 | 151 51 | Erebus. | 6 | -20 15 | | -59 32 | 170 05 | Terror. | 8 | -20 20 | | -59 32 | 170 05 | Terror. | 13 | -20 56 | | -59 32 | 169 59 | Erebus. | 8 | -21 28 | | -57 10 | 170 06 | Erebus. | 7 | -21 58 | | -58 19 | 170 39 | Terror. | 12 | -21 58 | | -57 40 | 170 26 | Erebus. | 7 | -21 59 | | -64 05 | 161 47 | Terror. | 7 | -22 19 | | -60 47 | 170 55 | Erebus. | 11 | -22 32 | | -64 08 | 163 04 | Terror. | 7 | -22 48 | + 5° to - 5°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -62 13 | 136 12 | Terror. | 5 | +1 35 | | -55 11 | 131 31 | Erebus. | 7 | +1 34 | | -55 04 | 132 44 | Erebus. | 9 | +1 09 | | -55 12 | 132 00 | Terror. | 7 | +0 45 | | -55 13 | 131 15 | Erebus. | 7 | +0 31 | | -55 04 | 132 10 | Terror. | 5 | +0 16 | | -54 59 | 132 13 | Terror. | 6 | -0 06 | | -62 06 | 136 07 | Erebus. | 6 | -0 27 | | -52 52 | 135 26 | Erebus. | 7 | -1 03 | | -62 15 | 136 23 | Erebus. | 7 | -1 13 | | -54 04 | 134 45 | Erebus. | 7 | -1 44 | | -54 04 | 134 30 | Erebus. | 6 | -1 50 | | -63 22 | 139 41 | Terror. | 8 | -3 29 | | -54 05 | 134 44 | Terror. | 11 | -3 44 | | -52 56 | 135 05 | Terror. | 8 | -3 55 | | -62 37 | 138 24 | Erebus. | 6 | -4 05 | | -51 11 | 136 54 | Erebus. | 5 | -4 39 | - 25° to - 35°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -65 06 | 172 20 | Erebus. | 8 | -25 06 | | -64 10 | 163 14 | Erebus. | 11 | -25 18 | | -64 18 | 172 31 | Erebus. | 9 | -25 33 | | -64 26 | 173 00 | Terror. | 9 | -25 52 | | -64 52 | 162 42 | Erebus. | 9 | -25 54 | | -64 40 | 172 44 | Erebus. | 8 | -25 57 | | -65 42 | 172 13 | Terror. | 7 | -26 17 | | -62 50 | 157 01 | Terror. | 7 | -26 49 | | -65 50 | 164 39 | Terror. | 9 | -26 56 | | -64 33 | 163 23 | Terror. | 10 | -26 58 | | -66 52 | 167 35 | Terror. | 8 | -27 06 | | -65 57 | 171 45 | Erebus. | 7 | -27 11 | | -66 27 | 169 44 | Erebus. | 8 | -27 21 | | -65 27 | 172 29 | Erebus. | 11 | -27 34 | | -65 30 | 172 34 | Erebus. | 10 | -28 08 | | -66 20 | 169 51 | Erebus. | 9 | -28 21 | | -65 43 | 165 10 | Erebus. | 13 | -28 23 | | -65 31 | 173 05 | Terror. | 12 | -29 17 | | -65 35 | 173 38 | Terror. | 12 | -29 42 | | -67 16 | 174 41 | Erebus. | 16 | -31 29 | | -67 56 | 167 31 | Erebus. | 8 | -32 35 | | -68 31 | 176 05 | Erebus. | 12 | -33 52 | | -68 00 | 175 05 | Erebus. | 13 | -34 04 | | -68 24 | 175 45 | Terror. | 10 | -34 38 | | -68 28 | 176 32 | Erebus. | 1 | -34 39 | | -68 55 | 176 20 | Erebus. | 5 | -34 58 | - 5° to - 15°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -51 15 | 136 49 | Terror. | 3 | -5 38 | | -63 13 | 140 00 | Erebus. | 12 | -5 58 | | -64 20 | 140 40 | Erebus. | 6 | -6 57 | | -44 37 | 143 56 | Terror. | 11 | -8 39 | | -44 18 | 145 04 | Erebus. | 9 | -8 46 | | -42 52 | 147 24 | Erebus. | 6 | -10 24 | | -44 24 | 152 58 | Terror. | 2 | -11 38 | | -65 04 | 142 47 | Erebus. | 2 | -12 37 | | -45 36 | 152 53 | Erebus. | 8 | -13 09 | | -46 08 | 154 15 | Erebus. | 8 | -13 38 | | -46 13 | 154 26 | Terror. | 4 | -13 47 | | -46 30 | 154 55 | Erebus. | 7 | -13 58 | | -64 17 | 148 52 | Terror. | 7 | -13 59 | | -49 18 | 160 18 | Terror. | 4 | -14 44 | - 15° to - 25°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -50 33 | 166 15 | Terror. | 42 | -15 29 | | -50 54 | 166 35 | Erebus. | 7 | -16 03 | | -52 22 | 169 38 | Terror. | 11 | -17 08 | | -49 47 | 161 00 | Erebus. | 8 | -17 16 | | -64 17 | 149 03 | Erebus. | 5 | -17 19 | - 35° to - 45°. | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | -69 23 | 167 45 | Terror. | 7 | -36 06 | | -68 59 | 167 46 | Erebus. | 12 | -36 12 | | -70 27 | 167 57 | Terror. | 11 | -37 41 | | -69 33 | 167 31 | Erebus. | 11 | -38 21 | | -70 03 | 167 30 | Erebus. | 10 | -39 21 | MDCCXLIII. ### General Table of Declination. (Continued.) | Lat. | Long. | Ship. | No. of observations | Declination | |------|-------|-------|---------------------|-------------| | | | | | | | -70 33 | 172 57 | Erebus. | 6 | -39 35 | | -70 23 | 167 23 | Erebus. | 7 | -39 45 | | -71 00 | 172 25 | Erebus. | 9 | -43 56 | | -71 22 | 170 56 | Erebus. | 10 | -44 01 | | -71 51 | 171 53 | Erebus. | 9 | -44 24 | | -71 08 | 172 07 | Terror. | 10 | -45 45 | | -71 52 | 171 19 | Terror. | 12 | -46 40 | | -71 21 | 171 14 | Terror. | 8 | -46 52 | | -71 55 | 172 00 | Erebus. | 9 | -48 12 | | -72 33 | 172 51 | Terror. | 8 | -48 49 | | -72 36 | 173 40 | Erebus. | 5 | -50 31 | | -72 16 | 174 09 | Erebus. | 6 | -51 41 | | -72 36 | 173 46 | Erebus. | 8 | -51 54 | | -72 40 | 175 17 | Terror. | 11 | -52 35 | | -73 01 | 175 55 | Erebus. | 12 | -52 41 | | -73 34 | 172 43 | Terror. | 8 | -54 34 | | -73 57 | 171 23 | Erebus. | 12 | -63 38 | | -73 53 | 171 37 | Terror. | 8 | -64 12 | | -74 01 | 171 42 | Erebus. | 10 | -64 25 | | -74 01 | 172 35 | Terror. | 5 | -65 04 | | -74 47 | 171 23 | Terror. | 10 | -65 41 | | -74 26 | 168 37 | Terror. | 6 | -68 40 | | -74 39 | 169 00 | Erebus. | 7 | -69 47 | | -74 51 | 168 10 | Terror. | 4 | -70 52 | | -74 46 | 168 42 | Erebus. | 10 | -71 08 | | -74 46 | 167 53 | Erebus. | 2 | -74 48 | | -76 40 | 188 40 | Erebus. | 5 | -77 53 | | -76 57 | 186 38 | Erebus. | 9 | -81 33 | | -77 18 | 192 38 | Erebus. | 13 | -81 50 | | -77 08 | 189 02 | Erebus. | 6 | -82 09 | | -77 11 | 192 58 | Erebus. | 6 | -82 26 | | -77 22 | 188 43 | Erebus. | 12 | -82 29 | | -77 07 | 192 22 | Terror. | 13 | -83 03 | | -76 57 | 188 30 | Terror. | 9 | -83 24 | | -77 17 | 191 35 | Erebus. | 6 | -83 56 | | -75 39 | 168 33 | Erebus. | 9 | -84 58 | | -77 04 | 188 28 | Terror. | 5 | -85 09 | | -76 23 | 177 25 | Erebus. | 2 | -85 10 | | -77 12 | 187 02 | Erebus. | 10 | -87 29 | | -76 25 | 177 35 | Terror. | 2 | -88 55 | | -77 22 | 186 21 | Erebus. | 6 | -89 19 | | -75 36 | 167 45 | Terror. | 2 | -89 32 | | -77 03 | 186 40 | Terror. | 10 | -89 37 | | -77 28 | 186 33 | Erebus. | 6 | -90 21 | | -75 28 | 168 12 | Terror. | 9 | -90 44 | | -77 09 | 188 22 | Erebus. | 9 | -91 07 | | -77 35 | 186 40 | Erebus. | 9 | -93 22 | | -77 36 | 186 41 | Terror. | 9 | -93 24 | | -77 44 | 188 00 | Erebus. | 8 | -93 41 | | -77 54 | 188 27 | Erebus. | 8 | -93 41 | | -77 51 | 191 01 | Erebus. | 5 | -93 43 | | -77 46 | 186 53 | Erebus. | 8 | -94 14 | | -75 52 | 167 00 | Erebus. | 8 | -94 27 | | -77 51 | 189 42 | Terror. | 7 | -94 42 | | -77 45 | 189 00 | Terror. | 6 | -94 59 | | -77 43 | 187 04 | Terror. | 8 | -95 21 | | -77 49 | 187 26 | Erebus. | 6 | -95 52 | | -77 51 | 187 38 | Erebus. | 6 | -96 00 | | -77 51 | 186 38 | Erebus. | 10 | -96 14 | | -77 47 | 180 34 | Erebus. | 1 | -96 17 | | -77 44 | 186 06 | Terror. | 5 | -97 11 | | -76 07 | 168 45 | Erebus. | 4 | -98 45 | | -75 58 | 168 50 | Terror. | 2 | -99 41 | | -76 10 | 166 02 | Erebus. | 4 | -99 41 | | -76 04 | 166 19 | Terror. | 5 | -100 14 | | -77 47 | 176 19 | Terror. | 5 | -102 09 | | -77 41 | 175 57 | Erebus. | 7 | -104 25 | | -77 50 | 178 00 | Erebus. | 4 | -105 21 | | -76 22 | 165 44 | Erebus. | 6 | -106 13 | | -76 47 | 169 26 | Terror. | 2 | -107 05 | | -76 32 | 166 30 | Terror. | 9 | -111 44 | | -76 36 | 166 18 | Erebus. | 13 | -113 23 | | -76 33 | 164 45 | Erebus. | 8 | -113 41 | | -77 22 | 172 04 | Terror. | 4 | -114 21 | Total number of observations 1368. No observation has been omitted or its result rejected. The scale of the declination chart has not permitted the insertion of all the results comprised in this table, and a few of those of the Terror have consequently been omitted in the very high latitudes where the figures are most crowded. The next number of these contributions, embracing the observations of the succeeding voyage, will contain a declination chart of the high latitudes on a more extended scale, in which all the results of both voyages will be inserted. General Table of the Inclinations observed in Her Majesty's Ship Erebus, from June 1840 to April 1841. | Lat. | Long. | No. of observations | Inclination | Lat. | Long. | No. of observations | Inclination | |------|-------|---------------------|-------------|------|-------|---------------------|-------------| | -48° 41' | 68° 54' | 9 | -70° 00' a | -68° 17' | 175° 00' | 5 | -83° 12' | | -48° 29' | 76° 55' | 2 | -70° 55' | -68° 32' | 175° 49' | 6 | -83° 28' | | -48° 17' | 80° 15' | 2 | -71° 50' | -68° 28' | 176° 31' | 5 | -83° 17' | | -47° 55' | 83° 00' | 2 | -72° 34' | -68° 28' | 176° 32' | 5 | -83° 35' e | | -47° 46' | 86° 18' | 2 | -73° 33' | -68° 53' | 176° 23' | 5 | -83° 40' | | -47° 12' | 89° 45' | 2 | -73° 35' | -70° 23' | 174° 50' | 4 | -85° 00' | | -47° 03' | 93° 00' | 2 | -74° 37' | -71° 15' | 171° 15' | 4 | -85° 50' | | -47° 39' | 102° 42' | 2 | -74° 28' | -71° 24' | 170° 44' | 4 | -85° 53' | | -47° 35' | 106° 26' | 2 | -74° 31' | -71° 47' | 170° 52' | 3 | -86° 10' | | -47° 45' | 110° 39' | 2 | -75° 08' | -72° 07' | 172° 19' | 4 | -86° 13' | | -47° 34' | 114° 15' | 2 | -75° 26' | -71° 52' | 172° 08' | 2 | -85° 53' | | -47° 41' | 121° 30' | 2 | -76° 04' | -71° 55' | 171° 51' | 4 | -85° 55' | | -47° 34' | 124° 43' | 2 | -76° 40' | -72° 12' | 172° 13' | 4 | -86° 41' | | -46° 44' | 128° 26' | 2 | -75° 41' | -72° 09' | 173° 35' | 3 | -86° 03' | | -46° 13' | 132° 00' | 2 | -75° 17' | -72° 57' | 176° 06' | 5 | -86° 11' | | -45° 59' | 135° 38' | 2 | -73° 48' | -72° 35' | 173° 34' | 4 | -86° 36' | | -45° 17' | 139° 19' | 2 | -73° 23' | -72° 31' | 173° 39' | 4 | -86° 51' | | -44° 24' | 141° 39' | 2 | -72° 37' | -73° 48' | 171° 47' | 7 | -87° 04' | | -44° 16' | 142° 38' | 2 | -73° 03' | -74° 06' | 170° 40' | 8 | -87° 12' | | -42° 52' | 147° 24' | 2 | -70° 38' b | -73° 56' | 171° 35' | 8 | -87° 11' | | -44° 16' | 149° 29' | 3 | -70° 41' | -74° 33' | 173° 23' | 7 | -87° 29' | | -45° 13' | 151° 57' | 3 | -71° 49' | -74° 43' | 169° 48' | 5 | -87° 25' | | -45° 33' | 152° 45' | 3 | -71° 37' | -74° 45' | 168° 23' | 4 | -88° 18' | | -46° 18' | 154° 30' | 3 | -72° 04' | -74° 55' | 169° 01' | 3 | -88° 21' | | -47° 46' | 157° 40' | 3 | -73° 14' | -75° 22' | 168° 48' | 4 | -88° 36' | | -49° 20' | 160° 13' | 3 | -74° 15' | -76° 06' | 168° 11' | 4 | -88° 27' | | -50° 28' | 164° 09' | 3 | -74° 23' | -77° 07' | 169° 56' | 2 | -88° 01' | | -50° 33' | 166° 19' | 3 | -73° 10' c | -77° 47' | 175° 43' | 4 | -86° 48' | | -52° 34' | 169° 10' | 7 | -73° 52' d | -77° 41' | 180° 54' | 2 | -85° 54' | | -54° 06' | 169° 09' | 4 | -74° 46' | -77° 06' | 189° 08' | 5 | -85° 56' | | -55° 50' | 170° 06' | 3 | -76° 16' | -77° 05' | 188° 36' | 5 | -86° 12' | | -57° 15' | 170° 40' | 3 | -77° 43' | -77° 09' | 188° 15' | 4 | -86° 23' | | -57° 54' | 170° 25' | 3 | -77° 51' | -77° 49' | 186° 30' | 5 | -86° 10' | | -58° 57' | 170° 57' | 4 | -78° 04' | -77° 17' | 185° 26' | 4 | -86° 49' | | -59° 43' | 169° 39' | 6 | -78° 34' | -77° 00' | 192° 18' | 5 | -85° 36' | | -60° 19' | 170° 20' | 7 | -78° 53' | -77° 07' | 192° 26' | 4 | -85° 26' | | -60° 46' | 170° 44' | 4 | -79° 06' | -77° 24' | 192° 56' | 4 | -85° 45' | | -61° 34' | 170° 40' | 3 | -79° 30' | -77° 10' | 192° 48' | 5 | -86° 06' | | -62° 06' | 172° 51' | 4 | -79° 41' | -77° 09' | 188° 43' | 6 | -85° 54' | | -62° 40' | 173° 40' | 1 | -79° 58' | -76° 59' | 186° 39' | 5 | -86° 23' | | -62° 44' | 174° 36' | 5 | -80° 09' | -77° 43' | 187° 10' | 5 | -85° 51' | | -64° 00' | 172° 44' | 4 | -81° 03' | -77° 55' | 189° 04' | 2 | -85° 49' | | -64° 06' | 172° 38' | 5 | -81° 03' | -77° 38' | 187° 00' | 5 | -86° 19' | | -64° 31' | 172° 57' | 6 | -81° 11' | -76° 22' | 188° 05' | 4 | -86° 07' | | -65° 58' | 172° 47' | 4 | -82° 20' | -76° 50' | 183° 26' | 3 | -86° 23' | | -66° 17' | 170° 57' | 4 | -82° 25' | -76° 17' | 175° 37' | 6 | -87° 15' | | -66° 30' | 169° 13' | 4 | -82° 40' | -76° 14' | 172° 35' | 1 | -87° 36' | | -66° 32' | 169° 45' | 4 | -82° 31' | -76° 06' | 168° 07' | 7 | -88° 21' | | -66° 23' | 170° 12' | 4 | -82° 53' | -76° 20' | 165° 32' | 4 | -88° 35' | | -65° 39' | 170° 44' | 4 | -81° 51' | -76° 36' | 164° 38' | 5 | -88° 19' | | -65° 22' | 172° 40' | 4 | -81° 43' | -75° 21' | 168° 06' | 6 | -87° 52' | | -66° 55' | 174° 31' | 3 | -82° 13' | -72° 13' | 171° 04' | 4 | -86° 23' | | -67° 27' | 174° 51' | 4 | -82° 58' | -70° 55' | 168° 43' | 3 | -85° 53' | a On shore at Kerguelen Island. b On shore at Van Diemen Island. c On shore at Auckland Island. d. On shore at Campbell Island. e On Ice. ## General Table of Inclination. (Continued.) | Lat. | Long. | No. of observations. | Inclination. | Lat. | Long. | No. of observations. | Inclination. | |------|-------|---------------------|--------------|------|-------|---------------------|--------------| | -70°41' | 167°20' | 4 | -85°51' | -65°14' | 144°37' | 3 | -85°05' | | -70°17' | 167°24' | 6 | -86°19' | -65°11' | 143°52' | 3 | -85°10' | | -70°14' | 167°16' | 3 | -86°06' | -65°09' | 143°07' | 6 | -85°16' | | -69°57' | 167°52' | 2 | -85°41' | -64°20' | 140°40' | 5 | -84°36' | | -69°24' | 167°55' | 5 | -85°28' | -63°09' | 139°28' | 7 | -84°46' | | -69°46' | 167°43' | 5 | -85°54' | -62°18' | 136°40' | 6 | -84°20' | | -69°06' | 167°43' | 5 | -85°26' | -61°18' | 134°02' | 5 | -83°55' | | -68°28' | 168°10' | 5 | -85°07' | -60°20' | 131°21' | 5 | -83°31' | | -67°47' | 167°22' | 5 | -84°28' | -59°25' | 130°14' | 5 | -82°52' | | -65°49' | 166°12' | 7 | -83°35' | -58°06' | 128°43' | 1 | -82°09' | | -65°53' | 162°14' | 3 | -83°51' | -57°22' | 127°37' | 2 | -81°43' | | -64°41' | 162°34' | 4 | -82°55' | -56°28' | 129°57' | 1 | -80°43' | | -64°20' | 163°29' | 4 | -82°54' | -55°02' | 131°48' | 5 | -80°15' | | -63°52' | 160°55' | 5 | -83°32' | -54°55' | 132°50' | 6 | -80°07' | | -62°41' | 156°59' | 5 | -82°33' | -54°02' | 134°59' | 8 | -79°39' | | -63°50' | 156°06' | 4 | -83°54' | -53°13' | 135°18' | 5 | -79°09' | | -64°12' | 154°47' | 3 | -84°06' | -51°16' | 136°50' | 4 | -77°59' | | -64°13' | 154°03' | 3 | -84°06' | -48°48' | 138°34' | 4 | -76°54' | | -64°20' | 153°02' | 5 | -84°14' | -46°55' | 139°55' | 3 | -75°42' | | -63°54' | 151°56' | 3 | -84°06' | -46°25' | 140°55' | 7 | -75°12' | | -64°18' | 149°09' | 3 | -84°48' | -44°57' | 144°18' | 8 | -73°54' | | -64°33' | 148°03' | 4 | -85°03' | -43°50' | 146°00' | 5 | -72°15' | General Table of the Intensity of the Magnetic Force from the observations made on board Her Majesty's Ship Erebus, between July 1840 and April 1841. | Latitude | Longitude | Intensity. London = 1·372 | |----------|-----------|--------------------------| | -48° 41' | 68° 54' | 1·465 | | -48° 29' | 76° 55' | 1·539 | | -48° 17' | 80° 15' | 1·574 | | -47° 55' | 83° 51' | 1·601 | | -47° 46' | 86° 18' | 1·575 | | -47° 12' | 89° 45' | 1·565 | | -47° 03' | 93° 00' | 1·712 | | -47° 26' | 99° 54' | 1·783 | | -47° 35' | 106° 26' | 1·863 | | -47° 40' | 112° 27' | 1·898 | | -47° 41' | 121° 30' | 1·992 | | -47° 34' | 124° 43' | 1·996 | | -46° 28' | 130° 13' | 2·007 | | -45° 59' | 135° 38' | 1·989 | | -45° 17' | 139° 19' | 2·005 | | -44° 24' | 141° 39' | 1·976 | | -44° 16' | 142° 38' | 1·934 | | -45° 02' | 143° 10' | 1·923 | | -46° 22' | 141° 06' | 1·954 | | -46° 29' | 140° 40' | 1·949 | | -43° 41' | 146° 03' | 1·892 | | -42° 52' | 147° 24' | 1·820 | | -44° 10' | 149° 29' | 1·844 | | -45° 13' | 151° 57' | 1·833 | | -45° 33' | 152° 45' | 1·843 | | -46° 18' | 154° 30' | 1·820 | | -47° 46' | 157° 40' | 1·817 | | -49° 20' | 160° 13' | 1·846 | | -50° 28' | 164° 09' | 1·858 | | -50° 33' | 166° 19' | 1·851 | | -52° 42' | 169° 10' | 1·877 | | -53° 47' | 169° 02' | 1·844 | | -54° 25' | 169° 16' | 1·874 | | -55° 50' | 170° 06' | 1·903 | | -57° 15' | 170° 40' | 1·914 | | -57° 54' | 170° 25' | 1·911 | | -58° 57' | 170° 57' | 1·920 | | -59° 41' | 169° 38' | 1·932 | | -60° 14' | 170° 15' | 1·951 | | Latitude | Longitude | Intensity. London = 1·372 | |----------|-----------|--------------------------| | -60° 31' | 170° 32' | 1·951 | | -61° 17' | 171° 14' | 1·960 | | -62° 40' | 174° 40' | 1·983 | | -64° 00' | 172° 44' | 1·976 | | -64° 06' | 172° 38' | 1·973 | | -64° 31' | 172° 55' | 1·988 | | -65° 46' | 171° 40' | 1·996 | | -66° 31' | 169° 20' | 2·008 | | -66° 23' | 170° 12' | 2·018 | | -65° 39' | 170° 44' | 2·046 | | -65° 22' | 170° 40' | 2·025 | | -66° 55' | 174° 31' | 2·009 | | -68° 30' | 175° 40' | 2·011 | | -68° 28' | 176° 31' | 2·032 | | -68° 28' | 176° 32' | 2·025 | | -68° 48' | 176° 45' | 2·016 | | -70° 23' | 174° 50' | 2·033 | | -71° 15' | 171° 15' | 2·030 | | -71° 24' | 170° 44' | 2·029 | | -71° 47' | 170° 52' | 2·056 | | -72° 07' | 172° 19' | 2·038 | | -71° 55' | 171° 51' | 2·028 | | -72° 12' | 172° 13' | 2·032 | | -72° 09' | 173° 35' | 2·026 | | -72° 57' | 176° 06' | 2·038 | | -72° 35' | 173° 34' | 2·035 | | -72° 31' | 173° 39' | 2·039 | | -73° 47' | 171° 50' | 2·052 | | -74° 10' | 170° 28' | 2·044 | | -74° 06' | 171° 20' | 2·052 | | -73° 56' | 172° 20' | 2·035 | | -74° 36' | 173° 01' | 2·037 | | -74° 44' | 169° 43' | 2·045 | | -75° 22' | 168° 48' | 2·048 | | -76° 06' | 168° 11' | 2·031 | | -76° 46' | 169° 22' | 2·040 | | -77° 47' | 175° 43' | 2·017 | | -77° 04' | 188° 24' | 2·017 | | -77° 17' | 185° 26' | 2·023 | | Latitude | Longitude | Intensity. London = 1·372 | |----------|-----------|--------------------------| | -77° 00' | 192° 18' | 2·039 | | -77° 10' | 192° 48' | 2·036 | | -77° 14' | 192° 02' | 2·020 | | -77° 09' | 188° 50' | 2·036 | | -76° 58' | 188° 40' | 2·035 | | -77° 43' | 187° 11' | 2·035 | | -76° 55' | 188° 49' | 2·048 | | -76° 50' | 188° 26' | 2·035 | | -76° 16' | 175° 50' | 2·017 | | -76° 03' | 169° 30' | 2·033 | | -76° 20' | 165° 32' | 2·041 | | -75° 03' | 168° 44' | 2·040 | | -71° 17' | 170° 43' | 2·037 | | -71° 04' | 170° 07' | 2·026 | | -70° 25' | 167° 27' | 2·036 | | -69° 24' | 167° 49' | 2·025 | | -68° 28' | 168° 10' | 2·047 | | -67° 52' | 167° 28' | 2·043 | | -65° 31' | 167° 42' | 2·041 | | -64° 58' | 162° 27' | 2·024 | | -64° 13' | 163° 18' | 2·018 | | -63° 57' | 161° 11' | 2·010 | | -62° 41' | 156° 59' | 2·022 | | -63° 50' | 156° 06' | 2·013 | | -64° 13' | 154° 03' | 2·011 | | -64° 20' | 153° 02' | 2·032 | | -63° 54' | 151° 56' | 2·023 | | -64° 26' | 148° 20' | 2·065 | | -64° 45' | 142° 00' | 2·068 | | -63° 09' | 139° 28' | 2·043 | | -61° 46' | 135° 12' | 2·051 | | -60° 19' | 131° 20' | 2·071 | | -58° 00' | 128° 40' | 2·056 | | -54° 44' | 132° 21' | 2·027 | | -53° 13' | 135° 18' | 2·047 | | -51° 16' | 136° 50' | 2·041 |