Account of experiments made with an invariable pendulum at the Royal Observatory at Greenwich, and at Port Bowen, on the eastern side of Prince Regent's Inlet

I. Account of experiments made with an invariable pendulum at the Royal Observatory at Greenwich, and at Port Bowen, on the eastern side of Prince Regent's Inlet. By Lieutenant Henry Foster, R. N. F. R. S. Read April 6, 1826. The determination of the length of the seconds' pendulum in different latitudes, is a subject, that has long been considered of much interest and importance, but more especially of late years, since the practical problem has received from the ingenuity of Captain Henry Kater, certain improvements and simplifications, which have rendered its results more accurate than had ever before been obtained. With the nature of these improvements I had already become acquainted when in H. M. S. Conway, with Captain Basil Hall, on the South American station, where, as will be seen in the Philosophical Transactions for 1823, several series of experiments were made by that officer and myself. Soon after my appointment to the N. W. Expedition under the command of Captain W. E. Parry, the Board of Longitude, at the suggestion of Captain Kater, did me the honour MDCCCXXVI. * B to entrust me with an invariable pendulum; and the details of the observations made with this instrument, together with a statement of all the attendant circumstances, are given in the following pages. The first set of experiments, which are marked (No. I.), were made at the Royal Observatory at Greenwich, in an apartment to the S. W. of the Transit Room, originally intended, I believe, for the observations of the eclipses of Jupiter's satellites, but upon this occasion kindly appropriated by Mr. Pond to my use. This room has a solid stone floor, on which the triangular supports for the pendulum and clock were placed. The roof is low, and being composed of wooden panels, the temperature of the room was materially affected by the state of the weather; on one occasion the thermometer ranged four degrees during the observations, although the light was admitted by a window on the north side. In the adjustments of the instruments employed in the experiments, I strictly adhered to the mode described by Captain Kater, in his paper read before the Royal Society in June, 1819. The intervals between the coincidences were determined by the disappearance of the white disk on the pendulum of the clock behind the tail-piece of the pendulum, and also by the mean of its disappearance and re-appearance. I was induced to take this additional trouble, in order to remove all possible objections which might be raised as to the accuracy of the result; and partly that I might, by actual trials, furnish materials for putting at rest the controversy on this subject. The method of disappearances has been followed by Captain Kater, and more lately by Captain Basil. experiments made with an invariable pendulum. HALL and General Sir THOMAS BRISBANE; that of taking a mean between the disappearance and re-appearance of the disk, has been practised by Mr. GOLDINGHAM at Madras, and by Captain SABINE. Theoretically, the mean of the disappearance and re-appearance, would give the true moment at which the two pendulums coincided at the lowest part of the arc of vibration, were it the object of this problem to determine that moment: but it is not:—the experiment being strictly comparative;—and the method of disappearances accomplishes all that is sought after, with perfect certainty, and with less than half the trouble. It may, however, be useful to know, that both methods give identically the same results; that is to say, the number of vibrations of a pendulum determined by the method of disappearance at one station, compared with the number deduced by the same method at another, give precisely the same acceleration or retardation as that which would result from comparing the number of vibrations at the first station, ascertained by taking the mean of disappearance and re-appearance, with those of the second station, ascertained by the same method. The results of the experiment contained in the following paper show this very obviously, as follows: | Vibrations by the method of disappearance alone at | Vibrations by the method of mean of disappearance and re-appearance at | |---------------------------------------------------|--------------------------------------------------| | Greenwich, . . . . . 86159,368 | Greenwich, . . . . . 86159,500 | | Port Bowen, . . . . . 86230,172 | Port Bowen, . . . . . 86230,313 | Acceleration by the method of disappearance . . . = 70,804 Acceleration by the mean of disappearance and re-appearance . . . = 70,813 Lieutenant Foster's account of The difference of the results amounts only to 9 ten-thousandths of a vibration in 24 hours. This, it may be observed, is the end and object of the problem; which, as I have before stated, is strictly a comparative one; and the only thing to be insisted upon is, that the same method should be followed, and the same adjustments of the apparatus strictly adhered to, at all the stations which are to be compared together. Supposing, however, that the vibrations recorded in the present experiments, ascertained by the one method, were compared with those determined by the other, the results would differ only 0.14 of a vibration in 24 hours; a quantity which does not occasion a difference of two ten-thousandths of an inch in the length of the deduced seconds' pendulum, nor of an unit in the denominator of the fraction expressing the ellipticity. There are cases, of course, dependant on the relative diameter of the white disk, to that of the tail-piece of the pendulum, in which a greater or less difference than the above would exist between the two methods so compared; but this is of no importance whatever, as the object of the problem is fully accomplished by adhering to the same method, whichever it be, at both stations, as before stated. It may not be useless to mention also, that Captain Kater did not adopt the method of disappearances in his comparative experiments, until after innumerable trials of other plans, including that of taking the mean of disappearance and re-appearance of the white disk; all of which he eventually abandoned for that of disappearances alone; and it is certainly to be regretted, that he did not publish an account of these unsuc- cessful trials, as it might have saved myself and others, much unnecessary labour. The clock used in these experiments was fitted with a gridiron pendulum, vibrating on knife edges in portions of hollow cylinders of agate, and belonged to the Royal Society. It was put in motion at Greenwich on the 17th of April, 1824, three days previous to the commencement of the experiment, and its rate ascertained by comparisons with the transit clock of the observatory each day at noon, and also during the series, at the commencement and at the conclusion. In these essential observations, I was kindly assisted by Mr. T. Taylor, jun. of the Royal Observatory. In making the observation of the coincidences, the following mode was pursued. The pendulum being placed in the Y's, was gently lowered until the knife edges rested on the agate planes; and the sides of the diaphragm placed in the focus of the eye-piece of the small telescope, were made just to coincide with, or embrace those of the tail-piece of the pendulum; and this adjustment was examined previous to every observation. The heights of the barometer, and of the thermometer suspended with its bulb about $\frac{2}{3}$ of the length of the pendulum below its point of suspension, and about $\frac{3}{4}$ of an inch in front of the middle of the bar, were taken and registered at the beginning and end of each set of observations. The pendulum was set in motion, by drawing it gently on one side with a piece of twine fastened to one of the legs of its support, until the point at the end of the tail-piece, was about $1^\circ, 2$ upon the arc; and a little before the pendulum of the clock attained its highest ascent on that side, the twine was let go, and the pendulum allowed to vibrate freely. The number of vibrations made by the pendulum in 24 hours reduced to the level of the sea, in vacuo and at a determinate temperature, were computed by the methods detailed in Captain Kater's paper before referred to. The second experiment marked (No. II.) was made at Port Bowen, on the eastern side of Prince Regent's Inlet, where the ships passed the winter of 1824-25. The observatory house, prepared in frame at Deptford, having double walls and roofs, three inches apart, was erected early in October on the north side of the harbour, upwards of a hundred feet above the level of the sea, on a bed of secondary limestone, of which this place is composed; the upper stratum consisted of small loose stones, that could only be removed to the depth of a few inches, below which, it was frozen so hard, that little impression could be made by the action of crows and pickaxes. The high table land, which characterises this coast, rises directly from the sea, on the south side of the harbour, to the height of between six and seven hundred feet; the upper part, presents a perpendicular cliff of one or two hundred feet, exhibiting alternate black and white horizontal stratifications of secondary limestone; it is also deeply excavated in a variety of places by the action of the weather on its less durable parts, thus giving to its outline the appearance of ruined towers and other ancient edifices. The debris, which has fallen from the upper part of the rock, has formed a steep shelving bank or "talus" along its base, except at those places where its outline is intersected by ravines, and here, projecting points are formed of the materials brought down by the melting of the winter's snow. To the eastward, at the head of Port Bowen, there is an extensive water course, and a low flat beach extending a quarter of a mile, and interrupting the high table land for the whole of that space. The land on the north side of the harbour from the head of the Port to Stoney Island (which lies about $\frac{1}{3}$ of a mile to the S. E. of the observatory), is similar in character to that already described on the south. From Stoney Island to the north point of entrance, the coast land is not above 200 feet high, but rises to the height of 900 feet at a little distance in the interior. The house was placed with its length at right angles to the meridian, and divided into two apartments; one was 10 feet square; the other was five feet wide, 10 feet long, and 10 feet high. For conducting the various observations in the winter, the former of these was lined with a thick woollen cloth called fearnought; the floor boarded, and a stove placed in it; the latter, being for the use of the transit instrument, had a slit 18 inches wide cut through the walls and roof, and a large stone placed on the top of a cask filled with sand, formed the pedestal for the instrument. Previous to the commencement of the experiments with the pendulum, it became necessary to remove the boarded floor, and block up the door opening into the room from the outside: the entrance now being through the slit into the transit room; the door in the middle of the partition between the rooms was protected by screens of canvas and fearnought on each side. The surface of the ground was then cleared away to as great a depth as possible, and large flat stones filled in with sand, formed the foundation for the supports of the pendulum and clock: care was also taken, that each support should stand on separate and unconnected stones. additional solidity was given to the supports, by attaching to the hindmost leg of each, a mass of lead, weighing from 40 to 50 lbs. The clock was now fixed to its support; but the pendulum of experiment remained on board the Hecla, until all the necessary preparations were completed. The small telescope containing the diaphragm, and used to observe the coincidences, was placed at the proper distance (9\(\frac{3}{4}\) feet) from the pendulum, on its stand outside of the room, in a porch originally erected for the use of the repeating circle: this stand was sunk so far into the ground, as to bring the object-end of the telescope, on a level with the bob of the pendulum of the clock. An aperture of a foot square was found sufficiently large for observing the coincidences, as well as the face of the clock, when sitting at the telescope, which was sheltered by a screen of canvas from any rush of air into the room, on opening the door of the porch. A transit instrument made by Dollond, of thirty inches focal length, and two inches aperture, was cemented to the pedestal already described, with plaster of Paris, at the latter end of October, and brought accurately into the meridian by the transits of high and low stars. A mark was then set up at the distance of 506 feet, to which it was afterwards always adjusted before making an observation: towards the end of March, the sun’s rays caused such an apparent wavering of the meridian mark, as to render its removal necessary, and it was accordingly transferred from the exposed situation where it stood at first, to the opposite side of the harbour, a distance of 6697 feet, where, being fixed in a hollow part of the rock, and completely shaded from the sun, it ever afterwards afforded the means of adjusting the instrument in a satisfactory manner, being perfectly steady and distinct. The allowance made for expansion, not being the result of experiments actually made on this particular pendulum, but from the deductions resulting from Captain Kater's experiments on a bar exactly similar, it became important in order to render the experiment strictly comparable with that at Greenwich, to keep the temperature of the room as near as possible to the one in which the previous experiments had been performed in England, namely, $50^\circ$. From the smallness of the room it was soon found, that the stove placed within it, produced incessant fluctuations in the temperature; it was therefore removed outside, to about six feet from the north wall of the house, and sunk into the ground level with the foundation of the observatory; built round with stones, and a tent was pitched over it. The room was now warmed by the smoke-pipe passing through it; and, to preserve the temperature of the pendulum more uniform, a large triangular covering of fearnought lined with racoon skins, was made to enclose the whole apparatus, except that part of the front required for observation. These arrangements effected the object so far, that the temperature of the room was seldom more than $3^\circ$, and frequently not one from $50^\circ$ during the observations. By a Sixes' self-registering thermometer, the mean range of temperature to which the pendulum was exposed in 24 hours was only $8^\circ$, and the extreme not more than $12^\circ$ during the series in June, whilst that of the atmosphere, varied from $23^\circ$ to $47^\circ$ of Fah. without any uniformity. Under these circumstances the pendulum of experiment was placed in the Y's on the 29th of May, 1825, and the MDCCCXXVI. Lieutenant Foster's account of adjustments finally completed on the 1st of June; the clock put in motion, and the apparatus for measuring the arc of vibration fixed in its place; the barometer and thermometer were also suspended after the manner described in the experiments at Greenwich. The perfect stability of the point of suspension being of the utmost consequence, spirit levels were arranged on the top of the pendulum frame and clock case, to indicate any giving way in the foundation of their respective supports from the effects of thaw, which at this time very generally prevailed; the foundations however remained solid, and the adjustments were preserved, during the whole course of these experiments, which were not commenced to any good purpose before the 14th of June, owing to an unfavourable change in the weather. This took place on the 7th of June, and was such, as rarely to permit a sight of the sun, and not one glimpse of the stars during the above interval from the 7th to 14th. In ascertaining the rate of the clock, I was confined to the transits of the sun at noon; of Arcturus and α Lyrae when passing south of the zenith. The sun's transit at midnight could not be taken, in consequence of the undulations of his limb, caused by being too near the top of the high land in that direction; neither could α Lyrae be seen soon after noon, from the general hazy state of the atmosphere at the elevation of 22 degrees. At the time of the sun's transit his rays were prevented from touching any part of the instrument, by a screen of canvas placed between the object-glass of the telescope and the slit in the roof of the house; it had a small hole, through which the observation was made, but being always covered except at the moment of noon, I had reason to believe that none of the adjustments were ever disturbed. In observing the times of transit, a steady going chronometer made by Henry Frodsham was used, and was found particularly convenient from its beating half seconds. A comparison between the clock and chronometer, was always taken before and after the passage of either sun or star. The time of transits shown by the face of the clock, was then deduced by direct proportion. All the comparisons are given in a separate table. It occasionally happened, owing to the state of the weather, that one of the stars was partially obscured at the time of its passing the meridian, so as to limit the observation to one or two wires only, whilst the transit of the other, over the whole five was obtained; in such cases the mean of the rates for the clock has been deduced, by giving a value to each, in the ratio of the number of wires observed. In the observation of the coincidences, the same mode was followed as in the experiments at Greenwich. The temperature of the pendulum, however, was more frequently taken by means of a small telescope, placed outside of the room, at a window to the south, and on the same level with the thermometer, suspended a little below the middle of the pendulum for that purpose. The weather on the whole was favourable during this series; it became somewhat unsettled toward the close; but as no day passed without at least one transit for the rate of the clock, I had no reason to be dissatisfied with any of the observations taken. A second series was made in July, under more favourable circumstances of weather, the results of which, differ only one-tenth of a vibration in 24 hours from those in June. The total number of factors for the first series being 275,5, and for the second 66, a mean in that ratio has finally been taken. The experiment marked III. was made at the Royal Observatory at Greenwich in November, 1825, after the return of the Expedition. The number of vibrations in 24 hours, deduced from this experiment, differing more than was likely to arise from errors in observation, being 0.24 of a vibration in excess of the number obtained before leaving England in 1824, I thought it right to repeat the experiment, especially as the rate of the clock appeared to be somewhat unsteady. The results of this repetition, made with the rate of the clock more uniform, being precisely the same, I have not considered it necessary to give them in detail. The difference alluded to in the number of vibrations of the pendulum in 24 hours, being on that side which would arise from the effects of wear of the knife edge of the pendulum, and which seemed probable, from the fine metallic line distinguishable on the agate planes after its removal, I feel disposed to adopt this explanation; and assuming an equable wear, I have taken the mean of the first and last series, as the actual number of vibrations made at Greenwich, to compare with those at Port Bowen, which being intermediate, of course required no correction on that account. The results of this comparison are given in a subsequent page preceding the third set of experiments. It will therefore be sufficient to state here, that the ellipticity of the earth deduced from these experiments, appears to be $\frac{1}{309.2}$. The experiments above described are of a nature to require, at every stage, the utmost degree of care; since an error, very small in apparent amount, either in the observations themselves, or in the subsequent computations, may prove fatal to that minute accuracy, without a due attention to which the nice objects of this problem might easily elude our notice. It will readily be understood, therefore, by every one conversant with such undertakings, that the observer, besides possessing adequate leisure, must be duly assisted in all parts of his progress by those persons with whom he is associated. And as it has been my good fortune to meet not only with the heartiest encouragement, but also the most efficient cooperation from the Commander of the Expedition, throughout the whole course of these and various other delicate researches, I feel it my duty not less on public grounds, than as a matter of private respect and gratitude, to make this acknowledgment of the source, to which every thing that may appear valuable in these enquiries is justly to be traced. HENRY FOSTER. Lieutenant Foster's account of No. I. Pendulum Experiments at the Royal Observatory at Greenwich, 1824. April 1824. Comparisons of the Clock with the Observatory Transit Clock. | Date | Time by Clock | Time by the Observatory Clock | Mean Time at Greenwich | Clock slow of Mean Time | |------------|---------------|-------------------------------|------------------------|-------------------------| | 20th Noon | h. m. s. | h. m. s. | h. m. s. | h. m. s. | | P. M. | 0 17 00 | 2 55 15,45 | 1 1 3,07 | 0 44 3,07 | | 21st A. M. | 3 38 00 | 6 16 48,84 | 4 22 3,47 | 0 44 3,47 | | Noon | 7 12 00 | 21 53 24,66 | 7 56 5,96 | 0 44 5,96 | | P. M. | 11 22 00 | 2 4 6,42 | 0 6 6,72 | 0 44 6,72 | | | 3 50 00 | 6 33 51,20 | 4 34 7,38 | 0 44 7,38 | | 22d A. M. | 7 56 00 | 22 38 00,22 | 8 40 9,60 | 0 44 9,60 | | Noon | 11 42 00 | 2 28 9,48 | 0 26 10,08 | 0 44 10,08 | | P. M. | 3 30 00 | 6 16 47,16 | 4 14 10,35 | 0 44 10,35 | | 23d A. M. | 8 5 00 | 22 54 32,95 | 8 49 12,75 | 0 44 12,75 | | Noon | 11 22 00 | 2 12 5,85 | 0 6 13,25 | 0 44 13,25 | | P. M. | 3 32 00 | 6 22 47,40 | 4 16 13,73 | 0 44 13,73 | | 24th A. M. | 7 38 00 | 22 31 27,81 | 8 22 15,56 | 0 44 15,56 | | Noon | 11 21 00 | 2 15 5,0 | 0 5 16,20 | 0 44 16,20 | | P. M. | 3 37 00 | 6 31 47,41 | 4 21 16,57 | 0 44 16,57 | | 25th A. M. | 8 17 00 | 23 14 33,70 | 9 1 18,64 | 0 44 18,64 | | Noon | 11 18 00 | 2 16 4,20 | 0 2 19,40 | 0 44 19,40 | From the preceding Table of Comparisons, this, of Rates losing has been deduced. | Time of Comparison | From 20 to 21 | From 20 to 22 | From 20 to 23 | From 20 to 24 | From 20 to 25 | From 21 to 22 | From 21 to 23 | From 21 to 24 | From 21 to 25 | From 22 to 23 | From 22 to 24 | From 22 to 25 | From 23 to 24 | From 23 to 25 | From 24 to 25 | |--------------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------| | h. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | s. | | 8 A. M. | | | | | | | | | | | | | | | | | Noon | 3,79 | 3,55 | 3,44 | 3,31 | 3,29 | 3,31 | 3,26 | 3,16 | 3,17 | 3,21 | 3,08 | 3,12 | 2,95 | 3,08 | 3,20 | | 4 P. M. | 3,88 | 3,45 | 3,42 | 3,27 | | 3,01 | 3,19 | 3,07 | | 3,38 | 3,10 | | 2,83 | | | | Rate in a mean solar day. | 3,83 | 3,50 | 3,43 | 3,29 | 3,29 | 3,28 | 3,26 | 3,14 | 3,15 | 3,24 | 3,06 | 3,06 | 2,88 | 3,00 | 3,10 | experiments made with an invariable pendulum. Observations of Coincidences at Greenwich, April 1824. Height above the level of the sea 181.5 feet. P. M. 20th April, Royal Observatory. Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 59 | 1 29 4 | 29 8 | | 1.18 | 1.140 | | | | | | | 40 37 | 40 41 | | 1.10 | 1.060 | | | | | | | 52 10 | 52 15 | | 1.02 | 0.980 | | | | | | | 2 3 42 | 3 50 | | 0.94 | 0.905 | | | | | | | 15 17 | 15 25 | | 0.87 | 0.845 | | | | | | | 26 51 | 26 59 | | 0.82 | 0.790 | | | | | | | 38 27 | 38 35 | | 0.76 | 0.740 | | | | | | | 50 00 | 50 9 | | 0.72 | 0.695 | | | | | | | 3 1 37 | 1 47 | | 0.67 | 0.650 | | | | | | | 59 | 13 12 | | 0.63 | | | | | | | | Mean. | | | | | | | | | A. M. 21st April, Royal Observatory. Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 54.5 | 8 33 20 | 33 25 | | 1.17 | 1.125 | | | | | | | 44 59 | 45 5 | | 1.08 | 1.035 | | | | | | | 56 37 | 56 44 | | 0.99 | 0.955 | | | | | | | 9 8 17 | 8 25 | | 0.92 | 0.890 | | | | | | | 19 56 | 20 5 | | 0.86 | 0.840 | | | | | | | 31 35 | 31 45 | | 0.82 | 0.790 | | | | | | | 43 13 | 43 25 | | 0.76 | 0.730 | | | | | | | 54 52 | 55 5 | | 0.70 | 0.680 | | | | | | | 10 6 34 | 6 43 | | 0.66 | 0.635 | | | | | | | 56.7 | 18 10 | | 0.61 | | | | | | | | Mean. | | | | | | | | | ### Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. **P. M. 21st April, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|-----------|----------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. | Disap. & Re-ap. | Disappearance | Disappearance and Re-ap. | | 58.5 | 1 31 17 | 31 23 | | | | s. | s. | vib. | vib. | | | 42 49 | 42 54 | | | | 1.22 | 1.180 | 692 | 691.5 | | | 54 22 | 54 27 | | | | 1.14 | 1.100 | 693 | 693 | | | 5 55 | 6 1 | | | | 1.06 | 1.025 | 693 | 693.5 | | | 17 27 | 17 37 | | | | 0.99 | 0.955 | 692 | 694 | | | 29 3 | 29 11 | | | | 0.92 | 0.885 | 696 | 695 | | | 40 37 | 40 45 | | | | 0.85 | 0.825 | 694 | 694 | | | 52 12 | 52 21 | | | | 0.75 | 0.775 | 695 | 695.5 | | | 3 3 45 | 3 57 | | | | 0.70 | 0.725 | 693 | 694.5 | | | 59.9 | 15 20 | | | | 0.65 | 0.675 | 695 | 695 | | | Mean. | | | | | | | 693.67 | 694 | Barometer { Beginning 29.90 } = 29.88 mean. **A. M. 22d April 1824, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|-----------|----------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. | Disap. & Re-ap. | Disappearance | Disappearance and Re-ap. | | 54.5 | 8 48 32 | 48 37 | | | | 1.20 | 1.160 | 696 | 696 | | | 9 00 8 | 00 13 | | | | 1.12 | 1.080 | 696 | 697 | | | 11 44 | 11 51 | | | | 1.04 | 1.005 | 698 | 698 | | | 23 22 | 23 29 | | | | 0.97 | 0.940 | 698 | 696.5 | | | 35 00 | 35 4 | | | | 0.91 | 0.875 | 696 | 698 | | | 46 36 | 46 44 | | | | 0.84 | 0.810 | 696 | 697 | | | 58 12 | 58 22 | | | | 0.78 | 0.755 | 696 | 696 | | | 10 9 48 | 9 58 | | | | 0.73 | 0.705 | 697 | 697.5 | | | 21 25 | 21 36 | | | | 0.68 | 0.655 | 698 | 697 | | | 58.8 | 33 3 | | | | 0.63 | | 696.78 | 697 | | | Mean. | | | | | | | 86148.72 | 86148.80 | Barometer { Beginning 29.81 } = 29.825 mean. experiments made with an invariable pendulum. Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. P. M. 22d April 1824, Royal Observatory. Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 59.5 | 1 29 55 | 29 59 | 29 57 | 1.20 | 1.160 | 690 | 690.5 | | | | | 41 25 | 41 30 | 41 27.5 | 1.12 | 1.080 | 691 | 691.5 | | | | | 52 56 | 53 2 | 52 59 | 1.04 | 1.000 | 692 | 692.5 | | | | | 2 4 28 | 4 35 | 4 31.5 | 0.96 | 0.925 | 691 | 691.5 | | | | | 15 59 | 16 7 | 16 3 | 0.89 | 0.860 | 692 | 692.5 | | | | | 27 31 | 27 40 | 27 35.5 | 0.83 | 0.800 | 693 | 693 | | | | | 39 4 | 39 12 | 39 8 | 0.77 | 0.745 | 693 | 694.5 | | | | | 50 37 | 50 48 | 50 42.5 | 0.72 | 0.695 | 691 | 691.5 | | | | | 3 2 8 | 2 20 | 2 14 | 0.67 | 0.645 | 694 | 693 | | | | 61.0 | 13 42 | 13 52 | 13 47 | 0.62 | | | | | | 60.2 Mean. A. M. 23d April 1824, Royal Observatory. Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 53.8 | 8 47 21 | 47 25 | 47 23 | 1.18 | 1.135 | 698 | 698 | | | | | 58 59 | 59 3 | 59 1 | 1.09 | 1.055 | 698 | 699 | | | | | 9 10 37 | 10 43 | 10 40 | 1.02 | 0.985 | 699 | 700 | | | | | 22 16 | 22 24 | 22 20 | 0.95 | 0.920 | 700 | 699 | | | | | 34 56 | 35 2 | 34 59 | 0.89 | 0.865 | 699 | 699.5 | | | | | 46 35 | 46 42 | 46 38.5 | 0.84 | 0.810 | 699 | 700 | | | | | 57 14 | 57 23 | 57 18.5 | 0.78 | 0.755 | 701 | 700.5 | | | | | 10 8 55 | 9 3 | 8 59 | 0.73 | 0.710 | 700 | 700.5 | | | | | 20 35 | 20 44 | 20 39.5 | 0.69 | 0.665 | 701 | 701 | | | | 53.9 | 32 16 | 32 25 | 32 20.5 | 0.64 | | | | | | 53.8 Mean. MDCCCXXVI. * D ### Observations of Coincidences at Greenwich — continued. Height above the level of the sea 181.5 feet. **P. M. 23d April 1824, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|-----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.5 | 1 25 29 | 25 31 | | | | | | | | | | 37 7 | 37 11 | | | | | | | | | | 48 47 | 48 51 | | | | | | | | | | 2 00 26 | 00 31 | | | | | | | | | | 12 5 | 12 13 | | | | | | | | | | 23 45 | 23 54 | | | | | | | | | | 35 26 | 35 34 | | | | | | | | | | 47 8 | 47 18 | | | | | | | | | | 58 50 | 58 59 | | | | | | | | | | 53.2 | 3 10 31 | | | | | | | | | | Mean. | | | | | | | | | Barometer { Beginning 29.17 } = 29.145 mean. **A. M. 24th April 1824, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|-----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 51.5 | 8 41 56 | 42 1 | | | | | | | | | | 53 36 | 53 41 | | | | | | | | | | 9 5 16 | 5 21 | | | | | | | | | | 16 56 | 17 3 | | | | | | | | | | 28 36 | 28 45 | | | | | | | | | | 40 17 | 40 25 | | | | | | | | | | 51 57 | 52 7 | | | | | | | | | | 10 3 38 | 3 47 | | | | | | | | | | 15 19 | 15 29 | | | | | | | | | | 54.5 | 26 58 | | | | | | | | | | Mean. | | | | | | | | | Barometer { Beginning 29.86 } = 29.90 mean. ### Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. **P. M. 24th April, 1824, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|-----------|-------------------------------|--------------------------|----------------|--------------------------------| | | h. m. s. | m. s. | | | | | | | | | 55.9 | 1 45 17 | 45 21 | | 1.18 | 1.135 | | | | | | | 56 51 | 56 57 | | 1.09 | 1.055 | | | | | | | 2 8 27 | 8 33 | | 1.02 | 0.985 | | | | | | | 20 1 | 20 8 | | 0.95 | 0.910 | | | | | | | 31 36 | 31 45 | | 0.87 | 0.845 | | | | | | | 43 13 | 43 20 | | 0.82 | 0.795 | | | | | | | 54 48 | 54 57 | | 0.77 | 0.745 | | | | | | | 3 6 23 | 6 34 | | 0.72 | 0.690 | | | | | | | 18 1 | 18 11 | | 0.66 | 0.640 | | | | | | 58.0 | 29 36 | 29 48 | | 0.62 | | | | | | Mean. | 695.44 | 695.89 | 86148.24 | 86148.41 | 1.27 | 86149.51 | 86149.68 | **A. M. 25th April, 1824, Royal Observatory.** Clock losing at a mean rate 3°.29. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. corr. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|-----------|-------------------------------|--------------------------|----------------|--------------------------------| | | h. m. s. | m. s. | | | | | | | | | 51.5 | 8 52 27 | 52 31 | | 1.16 | 1.115 | | | | | | | 9 4 8 | 4 13 | | 1.07 | 1.030 | | | | | | | 15 49 | 15 54 | | 0.99 | 0.955 | | | | | | | 27 30 | 27 37 | | 0.92 | 0.885 | | | | | | | 39 12 | 39 19 | | 0.85 | 0.825 | | | | | | | 50 53 | 51 1 | | 0.80 | 0.775 | | | | | | | 10 2 35 | 2 43 | | 0.75 | 0.725 | | | | | | | 14 15 | 14 25 | | 0.70 | 0.675 | | | | | | | 25 57 | 26 5 | | 0.65 | 0.635 | | | | | | 54.8 | 37 38 | 37 48 | | 0.62 | | | | | | Mean. | 701.22 | 701.56 | 86150.29 | 86150.41 | 1.21 | 86151.50 | 86151.62 | Vibrations of the Pendulum at the Royal Observatory at Greenwich. The Clock making 86396.71 vibrations at a mean rate in a mean solar day, April 1824. | Date | Baron. | Therm. | Diff. between Temp. Pend. and 50° | Vibrations of Pendulum in 24 h. corrected for Arc by Disappearance | Mean of Disap. and Re-app. | Corrections for Temperature | Vibrations in 24 hours at temperature of 50° | |------------|--------|--------|----------------------------------|---------------------------------------------------------------|-----------------------------|----------------------------|---------------------------------------------| | 20th P.M. | 30.20 | 59.0 | 9.0 | 86149.08 | 86149.19 | + 3.81 | 86152.89 | 86153.00 | | 21st A.M. | 30.00 | 55.6 | 5.6 | 86150.70 | 86150.85 | + 2.37 | 86153.07 | 86153.22 | | | | | | | | + 3.89 | 86152.88 | 86153.00 | | 22d A.M. | 29.82 | 59.2 | 9.2 | 86148.99 | 86149.11 | + 2.79 | 86152.84 | 86152.92 | | | | | | | | + 4.31 | 86152.59 | 86152.71 | | 23d A.M. | 29.86 | 56.6 | 6.6 | 86150.05 | 86150.13 | + 1.61 | 86152.58 | 86152.67 | | | | | | | | + 1.18 | 86152.53 | 86152.69 | | | | | | | | + 1.27 | 86152.40 | 86152.56 | | 24th A.M. | 29.90 | 53.0 | 3.0 | 86151.13 | 86151.29 | + 2.29 | 86152.43 | 86152.60 | | | | | | | | + 1.31 | 86152.81 | 86152.93 | | 25th A.M. | 30.05 | 53.1 | 3.1 | 86151.50 | 86151.62 | + 1.31 | 86152.70 | 86152.83 | | Mean | 29.82 | 56.0 | | | | | 86152.70 | 86152.83 | experiments made with an invariable pendulum. Results. | Correct Number of Vibrations made by the Pendulum in a mean solar day, by | | --- | --- | | Disappearance. | Mean of Disap. and Re-ap. | | **1824.** | | | From 20th April P. M. to 21st A. M. | | | 22d | 86152,44 | 86152,57 | | 23d | 86152,71 | 86152,82 | | 24th | 86152,67 | 86152,78 | | 25th | 86152,72 | 86152,85 | | — 21st — P. M. to 22d A. M. | | | 23d | 86152,87 | 86152,97 | | 24th | 86152,75 | 86152,85 | | 25th | 86152,79 | 86152,91 | | — 22d — P. M. to 23d A. M. | | | 24th | 86152,77 | 86152,90 | | 25th | 86152,63 | 86152,74 | | — 23d — P. M. to 24th A. M. | | | 24th | 86152,75 | 86152,89 | | 25th | 86152,79 | 86152,92 | | — 24th — P. M. to 25th A. M. | | | 25th | 86152,83 | 86152,98 | | 24th | 86152,81 | 86152,95 | Mean . . . . . . 86152,74 Barom. 29,82, Ther. 56°, Buoyancy = + 6,06 Elevation 181,5 feet, Correction = + 0,45 = 0,75 × 10 No. of vibra. at Greenwich in vacuo at the level of the sea, temp. 50° of Fah. 86159,25 The above correction for buoyancy of the atmosphere, has been deduced from the mean height of the barometer 29,82, and temperature 56°, together with the specific gravity of the pendulum supposed to be 8,61. That for elevation, by the duplicate ratio of distances from the earth’s centre (3954,583 miles) the ball of the pendulum at Greenwich being 181½ feet above the level of the sea. This was deduced from the Account of the Trigonometrical Survey of Great Lieutenant Foster's account of Britain; from which it appears that the height of the theodolite above the level of the sea was 214 feet. Theodolite above the floor of the transit room = 38 Floor of transit room above the level of the sea = 176 Ball of pendulum above floor of transit room = 5\(\frac{1}{2}\) Ball of pendulum above the level of the sea = 181\(\frac{1}{2}\) From the nature of the eminence, however, on which the pendulum stood, I have taken \(\frac{6}{10}\) of the correction so obtained, as the proper correction due to this elevation. experiments made with an invariable pendulum. June, 1825. Experiment II. at Port Bowen in Prince Regent's Inlet. Comparison of Chronometer I. with Clock at Port Bowen—(1st Series.) | Date | Chronometer | Clock | Difference | |------------|-------------|---------|------------| | June 14th, P.M. | h.m.s. | h.m.s. | h.m.s. | | 10 42 8.5 | 8 14 00 | 2 28 8.5 | | 10 53 8 | 8 25 00 | 2 28 8 | | 3 6 56 | 12 39 00 | 2 27 56 | | 3 16 55.5 | 12 49 00 | 2 27 55.5| | Noon, 15th | 2 2 25 | 11 35 00 | 2 27 25 | | | 2 23 24 | 11 56 00 | 2 27 24 | | P.M. 16th | 10 56 51.5 | 8 31 00 | 2 25 51.5 | | | 11 6 51 | 8 41 00 | 2 25 51 | | Noon, 17th | 1 4 8.5 | 11 39 00 | 2 25 8.5 | | | 2 26 7.5 | 12 1 00 | 2 25 7.5 | | Noon, 18th | 2 2 1 | 11 38 00 | 2 24 1 | | | 2 23 59 | 11 59 00 | 2 23 59 | | P.M. | 10 27 37.5 | 8 4 00 | 2 23 37.5 | | | 10 37 37.0 | 8 14 00 | 2 23 37 | | | 2 42 25.5 | 12 19 00 | 2 23 25.5 | | Noon, 19th | 3 4 24.5 | 12 41 00 | 2 23 24.5 | | | 2 11 53 | 11 49 00 | 2 22 53 | | P.M. | 2 22 52.5 | 12 00 00 | 2 22 52.5 | | | 10 26 30 | 8 4 00 | 2 22 30 | | | 10 36 29.5 | 8 14 00 | 2 22 29.5 | | | 2 32 18.5 | 12 10 00 | 2 22 18.5 | | Noon, 20th | 3 4 17 | 12 42 00 | 2 22 17 | | | 2 4 46 | 11 43 00 | 2 21 46 | | P.M. | 2 26 45 | 12 5 00 | 2 21 45 | | | 10 17 23 | 7 50 00 | 2 21 23 | | | 10 38 22 | 8 17 00 | 2 21 22 | | | 2 43 10.5 | 12 22 00 | 2 21 10.5 | | | 2 53 10 | 12 32 00 | 2 21 10 | | Noon, 21st | 1 56 39 | 11 36 00 | 2 20 39 | | | 2 28 37.5 | 12 8 00 | 2 20 37.5 | | Noon, 22d | 2 6 31 | 11 47 00 | 2 19 31 | | P.M. | 2 27 30 | 12 8 00 | 2 19 30 | | | 10 13 8 | 7 54 00 | 2 19 8 | | | 10 23 7.5 | 8 4 00 | 2 19 7.5 | | | 2 37 55.5 | 12 19 00 | 2 18 55.5 | | | 2 48 55 | 12 30 00 | 2 18 55 | | Noon, 23d | 2 4 23 | 11 46 00 | 2 18 23 | | P.M. | 2 25 22 | 12 7 00 | 2 18 22 | | | 10 11 00 | 7 53 30 | 2 18 00 | | | 10 21 59.5 | 8 4 00 | 2 17 59.5 | | | 2 46 47 | 12 29 00 | 2 17 47 | | | 2 57 46.5 | 12 40 00 | 2 17 46.5 | | Date | Stars | 1st Wire observed | 1st Wire corrected | Std Wire meridian | 4th | 5th | Mean Chron. | Comparison of Chron. and Clock | Mean Clock. | Clock at mean Noon. | |------------|----------------|-------------------|--------------------|------------------|-----|-----|-------------|-------------------------------|-------------|---------------------| | June 14th | Arcturus | | | | | | | | | | | P.M. | α Lyra | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 15th | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 16th, P.M. | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 17th | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 18th | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | P.M. | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 19th | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 20th, P.M. | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 21st | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 22nd | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | 23rd | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | | P.M. | Arcturus | | | | | | | | | | | | O's | | | | | | | | | | | | Centre | | | | | | | | | | | | 1st Limb | | | | | | | | | | | | 2nd Limb | | | | | | | | | | ## Observation of Coincidences at Port Bowen, June 1825 (1st Series.) **Night, June 14th, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra., in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | 50°5 | 9 46 26 | 46 30 | 46 28 | 1.17 | 1.125 | 603 | 696 | 86220,328 | vib. 2.069 | | | 57 59 | 58 9 | 58 4 | 1.08 | 1.040 | 604 | 695 | 86220,687 | 86221,046 1.768 | | | 10 9 33 | 9 45 | 9 39 | 1.00 | 0.960 | 704 | 701 | 86222,227 | 86223,176 1.507 | | | 21 17 | 21 23 | 21 20 | 0.92 | 0.890 | 608 | 699 | 86222,116 | 86222,470 1.295 | | | 32 55 | 33 3 | 32 59 | 0.86 | 0.830 | 608 | 698,5 | 86222,116 | 86222,293 1.122 | | | 44 33 | 44 42 | 44 37.5 | 0.80 | 0.770 | 609 | 699 | 86222,470 | 86222,470 0.969 | | | 56 12 | 56 21 | 56 16.5 | 0.74 | 0.715 | 609 | 699 | 86222,116 | 86222,470 0.836 | | | 11 7 50 | 8 1 | 7 55.5 | 0.69 | 0.670 | 608 | 699 | 86222,116 | 86222,470 0.734 | | | 19 28 | 19 41 | 19 34.5 | 0.65 | 0.620 | 699 | 699.5 | 86222,470 | 86222,647 0.628 | **Mean.** Correction for Temp. 0°.83. + 0.351 Vibra., in 24 h. at Temp. 50°. 86223,637 --- **Morning, June 15th, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra., in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | 50°5 | 1 40 54 | 40 58 | 40 56 | 1.15 | 1.110 | 696 | 697 | 86221,403 | vib. 2.014 | | | 52 30 | 52 36 | 52 33 | 1.07 | 1.025 | 698 | 698 | 86222,116 | 86221,760 2.014 | | | 2 4 8 | 4 14 | 4 11 | 0.98 | 0.950 | 698 | 698 | 86222,116 | 86221,760 1.718 | | | 15 46 | 15 53 | 15 49.5 | 0.92 | 0.890 | 701 | 701.5 | 86223,176 | 86222,293 1.476 | | | 27 27 | 27 35 | 27 31 | 0.86 | 0.830 | 700 | 700.5 | 86222,823 | 86223,000 1.122 | | | 39 7 | 39 16 | 39 11.5 | 0.80 | 0.775 | 700 | 701 | 86222,823 | 86223,000 0.982 | | | 50 47 | 50 58 | 50 52.5 | 0.75 | 0.725 | 700 | 701 | 86222,823 | 86223,000 0.859 | | | 3 2 27 | 2 41 | 2 34 | 0.70 | 0.675 | 707 | 705.5 | 86225,269 | 86224,750 0.745 | | | 14 14 | 14 25 | 14 19.5 | 0.65 | 0.625 | 704 | 704 | 86224,227 | 86224,227 0.638 | **Mean.** Correction for Temp. 1°.13. - 0.479 Vibra. in 24 h at Temp. 50°. 86223,702 --- MDCCCXXVI. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, 15th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | 49 | 9 7 41 | 7 45 | 7 43 | 1.20 | 1.160 | 698 | 86222,116 | 2.200 | 86224,316 | | | 19 19 | 19 24 | 19 21.5 | 1.12 | 1.075 | 700 | 86222,823 | 1.889 | 86224,712 | | | 30 59 | 31 4 | 31 1.5 | 1.03 | 0.995 | 699 | 86222,470 | 1.618 | 86224,488 | | | 42 38 | 42 45 | 42 41.5 | 0.96 | 0.925 | 701 | 86223,170 | 1.399 | 86224,575 | | | 54 19 | 54 25 | 54 22 | 0.89 | 0.860 | 700 | 86222,823 | 1.209 | 86224,032 | | | 10 59 | 6 7 | 6 3 | 0.83 | 0.800 | 701 | 86223,176 | 1.046 | 86224,222 | | | 17 40 | 17 48 | 17 44 | 0.77 | 0.745 | 702 | 86223,527 | 0.907 | 86224,434 | | | 29 22 | 29 31 | 29 26.5 | 0.72 | 0.700 | 701 | 86223,176 | 0.801 | 86223,977 | | | 41 3 | 41 13 | 41 8 | 0.68 | 0.660 | 702 | 86223,527 | 0.712 | 86224,239 | | 49.2 | 52 45 | 52 55 | 52 50 | 0.64 | | | | | | **Mean.** Correction for Temp. 0°.95. Vibrations in 24 h. at Temp. 50°. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | 49.05 | | | | | | | | | | **Afternoon, 15th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | 47 | 1 20 33 | 20 38 | 20 35.5 | 1.12 | 1.080 | 701 | 86223,176 | 1.907 | 86225,083 | | | 32 14 | 32 19 | 32 16.5 | 1.04 | 1.005 | 702 | 86223,527 | 1.650 | 86225,177 | | | 43 56 | 44 2 | 43 59 | 0.97 | 0.935 | 703 | 86223,878 | 1.429 | 86225,307 | | | 55 39 | 55 46 | 55 42.5 | 0.90 | 0.870 | 703 | 86223,878 | 1.237 | 86225,115 | | | 2 7 22 | 7 27 | 7 24.5 | 0.84 | 0.810 | 702 | 86223,527 | 1.073 | 86224,600 | | | 19 4 | 19 11 | 19 7.5 | 0.78 | 0.750 | 704 | 86224,227 | 0.920 | 86224,951 | | | 30 48 | 30 55 | 30 51.5 | 0.72 | 0.690 | 704 | 86224,227 | 0.776 | 86225,147 | | | 42 32 | 42 41 | 42 36.5 | 0.66 | 0.640 | 704 | 86224,227 | 0.670 | 86224,897 | | | 54 16 | 54 25 | 54 20.5 | 0.62 | 0.595 | 706 | 86224,923 | 0.579 | 86225,502 | | 46.5 | 3 6 2 | 6 11 | 6 6.5 | 0.57 | | | | | | **Mean.** Correction for Temp. 3°.5. Vibrations in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Night, 15th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance. | Time of Reappearance. | Mean of Disappearance and Reappearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|-----------------------|----------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 44 | 9 1 23 | 1 27 | | 1.16 | 1.110 | 703 | 86223,878 | vib. | 86225,892 | | 44 | 13 6 | 13 11 | | 1.06 | 1.025 | 703 | 86223,878 | 2.014 | 86226,067 | | 44 | 24 49 | 24 55 | | 0.99 | 0.955 | 704 | 86224,227 | 1.718 | 86225,771 | | 44 | 36 33 | 36 41 | | 0.85 | 0.820 | 704 | 86224,576 | 1.491 | 86226,067 | | 46 | 10 00 | 10 11 | | 0.79 | 0.760 | 704 | 86224,402 | 1.280 | 86225,856 | | 48 | 11 45 | 11 55 | | 0.73 | 0.705 | 704 | 86223,878 | 1.099 | 86225,682 | | 50 | 23 28 | 23 39 | | 0.68 | 0.660 | 702 | 86223,527 | 0.944 | 86225,171 | | 50.5 | 35 10 | 35 22 | | 0.64 | 0.620 | 701 | 86223,176 | 0.812 | 86224,865 | | 50.8 | 46 51 | 47 4 | | 0.60 | | | | | | Mean: 46.53 Diff. to 50°: 3.47 Correction for Temp. 3°.47° Vibrations in 24 h. at Temp. 50°: 86223,637 --- **Morning, 16th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance. | Time of Reappearance. | Mean of Disappearance and Reappearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|-----------------------|----------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49 | 12 57 | 57 8 | | 1.17 | 1.125 | 699 | 86222,470 | vib. | 86224,539 | | 49 | 8 43 | 8 48 | | 1.08 | 1.040 | 699 | 86222,470 | 2.069 | 86224,716 | | 49 | 20 22 | 20 28 | | 1.00 | 0.965 | 700 | 86222,823 | 1.768 | 86224,415 | | 48.2 | 32 2 | 32 9 | | 0.93 | 0.895 | 700 | 86222,823 | 1.522 | 86224,522 | | 48.2 | 43 42 | 43 50 | | 0.86 | 0.830 | 700 | 86223,000 | 1.309 | 86224,345 | | 47 | 55 22 | 55 33 | | 0.80 | 0.775 | 704 | 86222,823 | 1.122 | 86224,132 | | 47 | 7 6 | 7 15 | | 0.75 | 0.725 | 700 | 86223,352 | 0.982 | 86223,945 | | 47 | 18 46 | 18 57 | | 0.70 | 0.675 | 702 | 86223,527 | 0.860 | 86224,800 | | 47 | 30 28 | 30 39 | | 0.65 | 0.630 | 704 | 86224,227 | 0.745 | 86224,036 | | 47 | 43 12 | 43 22 | | 0.61 | | | | | | Mean: 47.8 Diff. to 50°: 2.2 Correction for Temp. 2°.2° Vibra. in 24 h. at Temp. 50°: 86223,430 ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, 16th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds by Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 47.2 | 9 2 57 | 3 0 0 | | | | | | | | | 49.8 | 14 37 | 14 42 | | | | | | | | | 49.8 | 26 19 | 26 25 | | | | | | | | | | 38 01 | 38 8 | | | | | | | | | 49.8 | 49 44 | 49 51 | | | | | | | | | | 1 26 | 1 35 | | | | | | | | | 49.8 | 13 10 | 13 19 | | | | | | | | | 24.52 | 25 1 | 25 56.5 | | | | | | | | | 36 35 | 36 43 | 36 39 | | | | | | | | | 49.8 | 48 17 | 48 26 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.72. Vibrations in 24 h. at Temp. 50°. --- **Afternoon, 16th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds by Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.8 | 1 29 27 | 29 30 | | | | | | | | | | 41 5 | 41 9 | | | | | | | | | | 52 43 | 52 47 | | | | | | | | | 50.3 | 2 4 21 | 4 26 | | | | | | | | | | 15 59 | 16 5 | | | | | | | | | 50.0 | 27 38 | 27 45 | | | | | | | | | 49.8 | 39 18 | 39 25 | | | | | | | | | | 50 58 | 51 2 | | | | | | | | | 50.0 | 3 2 38 | 2 47 | | | | | | | | | | 14 18 | 14 29 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.02. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Night, 16th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Vibra. in 24 h. cor. for Arc. | |-------|-----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------------|-----------------------------| | 49° | 9 47 14 | 47 17 | 47 15.5 | 1.19 | 1.145 | 699 | 690.5 | vib. | | | 59 53 | 59 57 | 59 55 | 1.10 | 1.060 | 699 | 699.5 | 1.837 | | | 10 11 32 | 11 37 | 11 34.5 | 1.02 | 0.980 | 699 | 699.5 | 1.570 | | | 23 11 | 23 17 | 23 14 | 0.94 | 0.910 | 699 | 699.5 | 1.354 | | | 34 50 | 34 57 | 34 53.5 | 0.88 | 0.850 | 700 | 700.5 | 1.178 | | | 45 30 | 45 38 | 45 34 | 0.82 | 0.790 | 699 | 699.5 | 1.020 | | | 57 9 | 57 19 | 57 14 | 0.76 | 0.735 | 700 | 700.5 | 0.883 | | | 11 8 49 | 9 00 | 8 54.5 | 0.71 | 0.690 | 700 | 699.5 | 0.776 | | | 20 29 | 20 39 | 20 34 | 0.67 | 0.645 | 701 | 701.5 | 0.681 | Mean. Correction for Temp. 0°.9. Vibrations in 24 h. at Temp. 50°. --- **Morning, 17th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Vibra. in 24 h. cor. for Arc. | |-------|-----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------------|-----------------------------| | 46° | 1 32 51 | 32 55 | 32 53 | 1.16 | 1.120 | 700 | 701.5 | vib. | | | 44 31 | 44 38 | 44 34.5 | 1.08 | 1.040 | 702 | 701 | 1.768 | | | 56 13 | 56 18 | 56 15.5 | 1.00 | 0.965 | 702 | 703 | 1.522 | | | 2 7 55 | 8 2 | 7 58.5 | 0.93 | 0.900 | 702 | 702.5 | 1.324 | | | 19 37 | 19 45 | 19 41 | 0.87 | 0.840 | 703 | 703.5 | 1.154 | | | 31 20 | 31 29 | 31 24.5 | 0.81 | 0.780 | 704 | 704.5 | 0.995 | | | 43 4 | 43 14 | 43 9 | 0.75 | 0.725 | 703 | 703 | 0.859 | | | 54 47 | 54 57 | 54 52 | 0.70 | 0.675 | 705 | 705.5 | 0.745 | | | 3 0 32 | 6 43 | 6 37.5 | 0.65 | 0.625 | 705 | 704.5 | 0.638 | Mean. Correction for Temp. 4°.0. Vibrations in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, 17th June, 1825, Port Bowen.** Hygr. { Temp. 52°. Dew Pt. 38°. } Bar. { Begs. 29,796 mer. 45°. Ends. 29,800 — 46°. } = 29,864 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|-----------------------------| | 50.8 | 9 10 51 | 10 55 | | | | | | | | | | 22 28 | 22 33 | | | | | | | | | 50.5 | 34 6 | 34 11 | | | | | | | | | | 45 44 | 45 51 | | | | | | | | | | 57 24 | 57 31 | | | | | | | | | 49.8 | 10 9 | 9 11 | | | | | | | | | | 20 44 | 20 53 | | | | | | | | | | 32 24 | 32 34 | | | | | | | | | | 44 5 | 44 15 | | | | | | | | | 50.7 | 55 47 | 55 57 | | | | | | | | Mean. Correction for Temp. 0°.45. Vib. in 24 h. at Temp. 50°. **Afternoon, 17th June, 1825, Port Bowen.** Hygr. { Temp. 52°. Dew Pt. 40°. } Bar. { Begs. 29,812 mer. 47°. Ends. 29,820 — 48°. } = 29,882 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|-----------------------------| | 52.2 | 1 13 34 | 13 37 | | | | | | | | | | 25 8 | 25 13 | | | | | | | | | | 36 44 | 36 49 | | | | | | | | | 51.8 | 48 22 | 48 27 | | | | | | | | | | 59 58 | 00 5 | | | | | | | | | | 2 11 37 | 11 44 | | | | | | | | | 52.0 | 23 14 | 23 22 | | | | | | | | | | 34 52 | 35 1 | | | | | | | | | | 46 31 | 46 39 | | | | | | | | | 53.0 | 58 8 | 58 18 | | | | | | | | Mean. Correction for Temp. 2°.25. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Night, 17th June, 1825, Port Bowen.** Hyg. { Temp. 52° Dew Pt. 36° } Bar. { Begs. 29.828 mer. 45°.5. Ends. 29.847 — 47°. } = 29.905 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. | Disap. & Re-ap. | Disappearance. | Mean of Disap. and Re-ap. | | 51 | 9 22 52 | 22 56 | | | | s. | s. | vib. | 86223,903 | | | 34 29 | 34 33 | | | | 1.19 | 1.145 | 697 | 86221,760 | | | 46 5 | 46 11 | | | | 1.02 | 1.060 | 696 | 86221,403 | | 51.5 | 57 41 | 57 49 | | | | 0.95 | 0.985 | 696 | 86221,760 | | | 9 18 | 9 27 | | | | 0.88 | 0.915 | 697 | 86221,760 | | | 20 56 | 21 5 | | | | 0.82 | 0.850 | 698 | 86222,116 | | 52.5 | 32 34 | 32 43 | | | | 0.75 | 0.785 | 698 | 86222,116 | | | 44 11 | 44 22 | | | | 0.70 | 0.725 | 697 | 86221,760 | | | 55 48 | 56 1 | | | | 0.66 | 0.680 | 697 | 86222,116 | | 51.5 | 11 7 26 | 7 40 | | | | 0.62 | 0.640 | 698 | 86222,293 | Mean. Correction for Temp. 1°.62. Vibra. in 24 h. at Temp. 50°. | 51.62 | Mean. | | | | | | | 86223,066 | 86223,264 | | | | | | | | | | + 0.685 | + 0.685 | **Morning, 18th June, 1825, Port Bowen.** Hyg. { Temp. 51° Dew Pt. 40° } Bar. { Begs. 29.841 mer. 46°. } = 29.908 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | 51 | 12 55 15 | 55 19 | | | | | | | | | | 1 6 51 | 6 56 | | | | | | | | | | 18 27 | 18 33 | | | | | | | | | 52 | 30 3 | 30 10 | | | | | | | | | | 41 40 | 41 47 | | | | | | | | | | 53 18 | 53 25 | | | | | | | | | 51.5 | 2 4 54 | 5 3 | | | | | | | | | | 10 32 | 10 42 | | | | | | | | | | 28 11 | 28 21 | | | | | | | | | 51 | 40 47 | 41 01 | | | | | | | | Mean. Correction for Temp. 1°.37. Vibra. in 24 h. at Temp. 50°. | 51.37 | Mean. | | | | | | | 86222,935 | 86223,134 | | | | | | | | | | + 0.579 | + 0.579 | ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, 18th June 1825, Port Bowen.** Hygr. { Temp. 51°.5. Dew Pt. 40°. } Bar. { Begs. 29.871 mer. 45°. Ends. 29.885 47°. } = 29.946 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|----------------------------|--------------------------|------------------|-----------------------------| | 51 | 9 17 48 | 17 52 | 17 50 | 1.17 | 1.125 | 696 | 86221,403 | vib. | 86223,472 | | | 29 24 | 29 28 | 29 26 | 1.08 | 1.045 | 696 | 86221,403 | 2.069 | 86223,472 | | | 41 00 | 41 5 | 41 25 | 1.01 | 0.975 | 698 | 86221,403 | 1.785 | 86223,367 | | 51.2 | 52 38 | 52 45 | 52 41.5 | 0.94 | 0.905 | 699 | 86222,116 | 1.554 | 86223,670 | | | 10 4 17 | 4 23 | 4 20 | 0.87 | 0.845 | 699 | 86222,470 | 1.339 | 86223,809 | | | 15 50 | 16 3 | 15 59.5 | 0.82 | 0.795 | 699 | 86222,470 | 1.166 | 86223,632 | | 51 | 27 35 | 27 43 | 27 39 | 0.77 | 0.745 | 700 | 86222,470 | 1.033 | 86223,503 | | | 39 15 | 39 23 | 39 19 | 0.72 | 0.695 | 697 | 86221,760 | 0.907 | 86223,730 | | | 50 52 | 51 1 | 50 56.5 | 0.67 | 0.645 | 700 | 86222,823 | 0.788 | 86222,726 | | 51.8 | 11 2 32 | 2 41 | 2 36.5 | 0.62 | | | 86222,823 | 0.680 | 86223,503 | Mean. Correction for Temp. 1°.25. Diff. to 50°. Vibra. in 24 h. at temp. 50°. --- **Afternoon, 18th June, 1825, Port Bowen.** Hygr. { Temp. 52°. Dew Pt. 42°. } Bar. { Begs. 29.896 mer. 48°. Ends. 29.901 48°. } = 29.965 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|----------------------------|--------------------------|------------------|-----------------------------| | 52.8 | 1 20 33 | 20 37 | 20 35 | 1.17 | 1.125 | 695 | 86221,046 | vib. | 86223,115 | | | 32 8 | 32 12 | 32 10 | 1.08 | 1.040 | 696 | 86221,403 | 2.669 | 86223,115 | | | 43 44 | 43 49 | 43 46.5 | 1.00 | 0.970 | 696 | 86221,403 | 1.768 | 86223,171 | | 52.2 | 55 20 | 55 27 | 55 23.5 | 0.94 | 0.905 | 697 | 86221,760 | 1.538 | 86223,298 | | | 2 6 57 | 7 5 | 7 1 | 0.87 | 0.840 | 698 | 86222,116 | 1.154 | 86223,277 | | 51.8 | 18 35 | 18 43 | 18 39 | 0.81 | 0.780 | 698 | 86222,116 | 0.995 | 86223,111 | | | 30 13 | 30 21 | 30 17 | 0.75 | 0.725 | 699 | 86222,470 | 0.859 | 86223,506 | | | 41 52 | 42 1 | 42 50.5 | 0.70 | 0.675 | 700 | 86222,823 | 0.745 | 86223,568 | | 51.2 | 53 32 | 53 41 | 53 36.5 | 0.65 | 0.630 | 698 | 86222,470 | 0.649 | 86222,765 | | | 3 5 10 | 5 21 | 5 15.5 | 0.61 | | | 86222,470 | | | Mean. Correction for Temp. 2°.0. Diff. to 50°. Vibra. in 24 h. at Temp. 50°. **Observation of Coincidences at Port Bowen (1st Series) — continued.** Night, 18th June, 1825, Port Bowen. Hygr. {Temp. 52°. Dew Pt. 40°.} Bar. {Beg. 29.900 mer. 46°.5. Ende. 29.898 — 45°.} = 29.964 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h., cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|----------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance Mean of Disap. and Re-ap. | Vib. | Disappearance Mean of Disap. and Re-ap. | | 51.5 | 8 59 43 | 59 47 | | 1.19 | 0 | 697 | 86221,760 | vib. | 86223,903 | | | 9 11 20 | 11 24 | | 1.10 | 1.145 | 697 | 86221,760 | 2.143 | 86223,903 | | | 22 55 | 23 00 | | 1.02 | 1.060 | 695 | 86221,046 | 1.837 | 86223,883 | | | 34 32 | 34 39 | | 0.95 | 0.985 | 697 | 86221,760 | 1.586 | 86223,702 | | | 46 9 | 46 16 | | 0.89 | 0.920 | 697 | 86221,760 | 1.384 | 86223,144 | | | 57 47 | 57 55 | | 0.83 | 0.860 | 698 | 86222,116 | 1.209 | 86223,325 | | | 9 25 | 9 34 | | 0.78 | 0.805 | 698 | 86222,116 | 1.059 | 86223,175 | | | 21 3 | 21 13 | | 0.72 | 0.750 | 698 | 86222,116 | 0.920 | 86223,390 | | | 32 42 | 32 53 | | 0.66 | 0.690 | 699 | 86222,470 | 0.776 | 86223,423 | | | 44 22 | 44 31 | | 0.62 | 0.640 | 700 | 86222,470 | 0.670 | 86223,140 | Mean. Diff. to 50°. Correction for Temp. 1°.15. + 0.487 Vibra. in 24 h. at Temp. 50°. 86223,770 Morning, 19th June, 1825, Port Bowen. Hygr. {Temp. 51°. Dew Pt. 40°.} Bar. {Beg. 29.895 mer. 45°. Ende. 29.878 — 44°.2.} = 29.956 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h., cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|----------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance Mean of Disap. and Re-ap. | Vib. | Disappearance Mean of Disap. and Re-ap. | | 51.0 | 1 13 59 | 14 3 | | 1.18 | 1.135 | 695 | 86221,046 | vib. | 86223,152 | | | 50.8 | 25 34 | | 1.09 | 1.055 | 696 | 86221,043 | 2.106 | 86223,509 | | | 50.4 | 37 10 | | 1.02 | 0.985 | 696 | 86221,582 | 1.820 | 86223,402 | | | 50.0 | 48 48 | | 0.95 | 0.915 | 698 | 86222,116 | 1.586 | 86223,702 | | | 51.0 | 2 00 26 | | 0.88 | 0.850 | 698 | 86222,116 | 1.369 | 86223,348 | | | 52.0 | 12 3 | | 0.82 | 0.795 | 697 | 86221,760 | 1.178 | 86222,938 | | | 52.2 | 23 40 | | 0.77 | 0.745 | 697 | 86221,760 | 1.033 | 86222,793 | | | 51.5 | 35 17 | | 0.72 | 0.695 | 698 | 86221,938 | 0.907 | 86222,607 | | | 51.4 | 46 55 | | 0.67 | 0.645 | 699 | 86222,293 | 0.788 | 86222,904 | | | 51.1 | 58 34 | | 0.62 | 0.645 | 699 | 86222,470 | 0.680 | 86223,150 | Mean. Diff. to 50°. Correction for Temp. 1°.14. + 0.482 Vibra. in 24 h. at Temp. 50°. 86223,595 MDCCCXXVI. * F ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, June 19th, 1825, Port Bowen.** - **Hyg.**: Temp. 52°5. Bar. Begs. 29.823 mer. 47°. Dew Pt. 42°. - **Clock gaining at a mean rate 69°.88.** - **Begs. 29.877 mean cor. Ends. 29.800 — 48°.** to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibra. in 24 h. by | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|------------------|----------|-------------------------------|---------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappear. | Mean of Disap. and Re-ap. | Vibra. Disappear. | | 52.5 | 9 16 50 | 16 54 | | 1.18 | 1.140 | 695 | 86221,046 | 86221,225 | vib. 2,125 | | | 28 25 | 28 30 | | 1.10 | 1.060 | 695 | 86221,046 | 86221,225 | 1,837 | | | 40 00 | 40 6 | | 1.02 | 0.985 | 697 | 86221,760 | 86221,760 | 1,586 | | 52.0 | 51 37 | 51 43 | | 0.95 | 0.920 | 697 | 86221,760 | 86221,938 | 1,384 | | | 10 3 14 | 3 21 | | 0.89 | 0.860 | 697 | 86221,760 | 86221,938 | 1,209 | | | 14 51 | 14 59 | | 0.83 | 0.800 | 697 | 86221,760 | 86221,938 | 1,046 | | 51.8 | 26 28 | 26 37 | | 0.77 | 0.745 | 696 | 86221,403 | 86221,116 | 0,907 | | | 38 4 | 38 17 | | 0.72 | 0.690 | 704 | 86224,227 | 86223,527 | 0,776 | | | 49 48 | 49 57 | | 0.66 | 0.635 | 698 | 86222,116 | 86222,470 | 0,659 | | 51.2 | 11 1 26 | 1 37 | | 0.61 | | | | | | **Mean.** | | | | | | | | | | | | 51.87 | | | | | | | | | | **Correction for Temp. 1°.87.** | | | | | | | | | | | **Vibra. in 24 h. at Temp. 50°.** | | | | | | | | | | | **Afternoon, 19th June, 1825, Port Bowen.** - **Hyg.**: Temp. 52°5. Bar. Begs. 29.784 mer. 48°. Dew Pt. 42°. - **Clock gaining at a mean rate 69°.88.** - **Begs. 29.842 mean cor. Ends. 29.770 — 48.2°.** to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibra. in 24 h. by | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|------------------|----------|-------------------------------|---------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappear. | Mean of Disap. and Re-ap. | Vibra. Disappear. | | 52.5 | 1 24 31 | 24 35 | | 1.10 | 1.055 | 695 | 86221,046 | 86221,403 | 1,820 | | | 36 6 | 36 12 | | 1.01 | 0.970 | 697 | 86221,760 | 86221,938 | 1,538 | | | 47 45 | 47 50 | | 0.93 | 0.890 | 698 | 86222,116 | 86221,938 | 1,295 | | 52.2 | 59 21 | 59 27 | | 0.85 | 0.825 | 697 | 86222,116 | 86221,938 | 1,110 | | | 2 10 58 | 11 5 | | 0.80 | 0.775 | 698 | 86222,116 | 86222,116 | 0,982 | | | 22 36 | 22 43 | | 0.75 | 0.725 | 698 | 86222,116 | 86222,470 | 0,859 | | 51.8 | 34 14 | 34 23 | | 0.70 | 0.675 | 698 | 86222,116 | 86222,470 | 0,745 | | | 45 52 | 46 3 | | 0.65 | 0.630 | 700 | 86222,823 | 86222,470 | 0,649 | | | 57 32 | 57 41 | | 0.61 | 0.590 | 700 | 86222,823 | 86222,823 | 0,569 | | 52.0 | 3 9 12 | 9 21 | | 0.57 | | | | | | **Mean.** | | | | | | | | | | | **Correction for Temp. 2°.12.** | | | | | | | | | | | **Vibra. in 24 h. at Temp. 50°.** | | | | | | | | | | | ## Observation of Coincidences at Port Bowen (1st Series) — continued. **Night, 19th June 1825, Port Bowen.** Hygr. {Temp. 52°.5. Dew Pt. 42°.} Bar. {Begs. 29.759 mer. 47°. Ends. 29.750 — 46°.8.} = 29.819 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.5 | 9 32 16 | 32 19 | | 1.16 | 1.120 | 695.5 | 86221,046 | 2.051 | 86223,097 | | | 43 51 | 43 53 | | 1.08 | 1.040 | 694 | 86220,687 | 1.768 | 86222,455 | | | 55 25 | 55 31 | | 1.00 | 0.970 | 696 | 86221,403 | 1.538 | 86222,941 | | 52.0 | 10 7 1 | 7 8 | | 0.94 | 0.910 | 697 | 86221,760 | 1.354 | 86223,114 | | | 18 38 | 18 45 | | 0.88 | 0.850 | 697 | 86221,760 | 1.178 | 86223,116 | | | 30 15 | 30 23 | | 0.82 | 0.790 | 697 | 86221,760 | 1.020 | 86223,136 | | 52.0 | 41 52 | 42 2 | | 0.76 | 0.735 | 698 | 86222,116 | 0.883 | 86222,999 | | | 53 30 | 53 41 | | 0.71 | 0.685 | 699 | 86222,470 | 0.766 | 86223,236 | | | 11 5 9 | 5 19 | | 0.66 | 0.640 | 699 | 86222,470 | 0.670 | 86223,140 | | | 16 48 | 16 59 | | 0.62 | | | | | | | 51.8 | | | | | | | | | | **Mean.** | 52.07 | | | | | | | | | | **Diff. to 50°.** | 2.07 | | | | | | | | | | Correction for Temp. 2°.07. | 86222,967 | 86223,125 | | + 0.875 | + 0.875 | Vibra. in 24 h. at Temp. 50°. | 86223,842 | 86224,000 | --- **Morning, 20th June 1825, Port Bowen.** Hygr. {Temp. 52°. Dew Pt. 42°.} Bar. {Begs. 29.749 mer. 46°. Ends. 29.743 — 46°.} = 29.813 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|----------------|----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.5 | 0 55 4 | 55 9 | | 1.12 | 1.080 | 696 | 86221,403 | 1.007 | 86223,310 | | | 1 6 40 | 6 45 | | 1.04 | 0.995 | 696 | 86221,403 | 1.618 | 86223,021 | | | 18 16 | 18 22 | | 0.95 | 0.915 | 696 | 86221,403 | 1.369 | 86222,772 | | | 29 52 | 30 00 | | 0.88 | 0.855 | 697 | 86221,760 | 1.193 | 86222,953 | | | 41 29 | 41 37 | | 0.83 | 0.805 | 697 | 86221,760 | 1.059 | 86222,819 | | | 53 6 | 53 14 | | 0.78 | 0.755 | 699 | 86222,470 | 0.932 | 86223,402 | | 51.8 | 2 4 45 | 4 53 | | 0.73 | 0.705 | 698 | 86222,116 | 0.812 | 86222,928 | | | 16 23 | 16 32 | | 0.68 | 0.655 | 697 | 86221,760 | 0.701 | 86222,461 | | | 28 00 | 28 16 | | 0.63 | 0.610 | 699 | 86222,470 | 0.608 | 86223,078 | | | 39 39 | 39 56 | | 0.59 | | | | | | | 51.2 | | | | | | | | | | **Mean.** | 51.77 | | | | | | | | | | **Diff. to 50°.** | 1.77 | | | | | | | | | | Correction for Temp. 1°.77. | 86222,972 | 86223,208 | | + 0.748 | + 0.748 | Vibra. in 24 h. at Temp. 50°. | 86223,720 | 86223,956 | ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Forenoon, 20th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration, | Mean Arc. | Interval in seconds of Clock, | Observed vibra. in 24 h. by | Correct. for Arc., | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|------------------|----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 5° | 9 27 45 | 27 48 | | | | | | | | | | 39 20 | 39 25 | | | | | | | | | | 50 58 | 51 3 | | | | | | | | | 5°.8 | 10 2 36 | 2 42 | | | | | | | | | | 14 14 | 14 21 | | | | | | | | | | 25 53 | 26 1 | | | | | | | | | 5°.3 | 37 33 | 37 41 | | | | | | | | | | 49 14 | 49 21 | | | | | | | | | | 11 00 | 52 1 | | | | | | | | | 5°.2 | 12 33 | 12 41 | | | | | | | | **Mean.** **Correction for Temp. 0°.82.** **Vibra. in 24 h. at Temp. 5°.** --- **Afternoon, 20th June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration, | Mean Arc. | Interval in seconds of Clock, | Observed vibra. in 24 h. by | Correct. for Arc., | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|------------------|----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 5° | 1 32 54 | 32 57 | | | | | | | | | | 43 31 | 43 35 | | | | | | | | | | 55 8 | 55 13 | | | | | | | | | 5°.2 | 2 6 46 | 6 51 | | | | | | | | | | 18 24 | 18 32 | | | | | | | | | | 30 3 | 30 11 | | | | | | | | | 5°.1 | 41 42 | 41 51 | | | | | | | | | | 53 22 | 53 31 | | | | | | | | | | 3 5 4 | 3 13 | | | | | | | | | 5°.1 | 16 44 | 16 52 | | | | | | | | **Mean.** **Correction for Temp. 0°.3.** **Vibra. in 24 h. at Temp. 5°.** ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Night, 20th June, 1825, Port Bowen.** Clock gaining 69°.88 at a mean rate. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibrat. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 0 | 9 48 50 | 48 54 | | | | | | | | | 49.5 | 10 00 26 | 00 32 | | | | | | | | | 50.0 | 12 1 | 12 9 | | | | | | | | | 51.5 | 23 35 | 23 43 | | | | | | | | | 55.0 | 35 9 | 35 16 | | | | | | | | | 55.5 | 46 41 | 46 50 | | | | | | | | | 57.0 | 58 13 | 58 21 | | | | | | | | | 56.0 | 9 45 | 9 54 | | | | | | | | | 56.5 | 21 19 | 21 30 | | | | | | | | | 55.2 | 32 53 | 33 4 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 4°.35°. Vibra. in 24 h. at Temp. 50°. --- **Forenoon, 21st June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibrat. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.8 | 9 34 13 | 34 19 | | | | | | | | | 48.5 | 45 53 | 45 58 | | | | | | | | | 49.0 | 57 31 | 57 38 | | | | | | | | | 49.5 | 10 9 11 | 9 17 | | | | | | | | | 50.0 | 20 50 | 20 56 | | | | | | | | | 50.8 | 32 28 | 32 35 | | | | | | | | | 50.8 | 44 7 | 44 15 | | | | | | | | | 50.6 | 55 47 | 55 56 | | | | | | | | | 50.5 | 11 7 27 | 7 36 | | | | | | | | | 50.3 | 19 7 | 19 16 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.06°. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Afternoon, 21st June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 5° | 1 31 23 | 31 27 | | | | | | | | | | 42 54 | 42 59 | | | | | | | | | | 54 33 | 54 37 | | | | | | | | | 49°5 | 2 6 17 | 6 22 | | | | | | | | | | 17 55 | 18 2 | | | | | | | | | | 29 35 | 29 42 | | | | | | | | | 49°5 | 41 15 | 41 23 | | | | | | | | | | 52 55 | 53 4 | | | | | | | | | 49° | 3 4 36 | 4 46 | | | | | | | | | | 16 17 | 16 28 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.25. Vibra. in 24 h. at Temp. 50°. --- **Night, 21st June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 53°5 | 9 17 54 | 17 58 | | | | | | | | | 53°2 | 29 27 | 29 32 | | | | | | | | | 53°0 | 41 3 | 41 10 | | | | | | | | | 52°5 | 52 38 | 52 46 | | | | | | | | | 52°0 | 10 4 15 | 4 23 | | | | | | | | | 50°0 | 15 53 | 16 2 | | | | | | | | | 49°5 | 27 33 | 27 41 | | | | | | | | | 51°5 | 39 11 | 39 22 | | | | | | | | | 52°0 | 50 50 | 51 2 | | | | | | | | | 53°0 | 11 2 28 | 2 42 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 2°.02. Vibra. in 24 h. at Temp. 50°. **Observation of Coincidences at Port Bowen (1st Series)—continued.** **Morning, 22d June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-----------------------------|-------------------------------|------------------|--------------------------------| | 5° | h. m. s. | m. s. | | | | | | | | | 50 | 0 49 43 | 49 48 | | 1.12 | 1.080 | | | | | | | 1 20 1 | 1 23 | | 1.04 | 1.005 | | | | | | | 12 58 13 | 13 2 | | 0.97 | 0.935 | | | | | | | 36 13 36 | 24 24 | | 0.90 | 0.870 | | | | | | | 47 53 48 | 48 4 | | 0.84 | 0.810 | | | | | | | 59 31 55 | 44 59 | | 0.73 | 0.705 | | | | | | | 2 11 13 | 11 24 | | 0.68 | 0.660 | | | | | | | 22 51 23 | 23 3 | | 0.64 | 0.620 | | | | | | | 34 30 34 | 43 34 | | 0.60 | | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 0°.56.** **Vibra. in 24 h. at Temp. 50°.** --- **Forenoon, 22d June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-----------------------------|-------------------------------|------------------|--------------------------------| | 5° | h. m. s. | m. s. | | | | | | | | | 50 | 9 31 13 | 31 18 | | 1.10 | 1.060 | | | | | | | 42 52 42 | 56 42 | | 1.02 | 0.985 | | | | | | | 54 27 54 | 34 54 | | 0.95 | 0.920 | | | | | | | 10 6 7 | 6 14 | | 0.89 | 0.860 | | | | | | | 17 48 17 | 55 17 | | 0.83 | 0.800 | | | | | | | 29 29 29 | 36 29 | | 0.77 | 0.745 | | | | | | | 41 4 41 | 4 41 | | 0.72 | 0.695 | | | | | | | 52 51 53 | 00 52 | | 0.67 | 0.605 | | | | | | | 11 4 32 | 4 43 | | 0.62 | 0.545 | | | | | | | 16 13 16 | 23 16 | | 0.58 | 0.600 | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 1°.23.** **Vibra. in 24 h. at Temp. 50°.** ### Observation of Coincidences at Port Bowen (1st Series) — continued. **Afternoon, 22nd June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.8 | 1 10 51 | 10 54 | 10 52,5 | 1.18 | 1.140 | | | | | | | 22 28 | 22 34 | 22 31 | 1.10 | 1.060 | | | | | | | 34 6 | 34 11 | 34 8,5 | 1.02 | 0.990 | | | | | | | 45 46 | 45 52 | 45 49 | 0.96 | 0.930 | | | | | | | 57 25 | 57 32 | 57 28,5 | 0.90 | 0.865 | | | | | | | 2 9 6 | 9 14 | 9 10 | 0.83 | 0.800 | | | | | | 48.6 | 20 47 | 20 54 | 20 50,5 | 0.77 | 0.745 | | | | | | | 32 27 | 32 38 | 32 32,5 | 0.72 | 0.690 | | | | | | | 44 10 | 44 20 | 44 15 | 0.66 | 0.640 | | | | | | | 55 52 | 56 4 | 55 58 | 0.62 | | | | | | Mean. Correction for Temp. 1°.73. Diff. to 50°. Vibra. in 24 h. at Temp. 50°. --- **Night, 22nd June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49 | 9 6 9 | 6 12 | 6 10,5 | 1.18 | 1.135 | | | | | | | 17 47 | 17 51 | 17 49 | 1.09 | 1.045 | | | | | | | 29 25 | 29 32 | 29 28,5 | 1.00 | 0.965 | | | | | | 49.2 | 41 5 | 41 12 | 41 8,5 | 0.93 | 0.895 | | | | | | | 52 44 | 52 52 | 52 48 | 0.86 | 0.835 | | | | | | | 10 4 24 | 4 31 | 4 27,5 | 0.81 | 0.780 | | | | | | 50.2 | 16 2 | 16 9 | 16 5,5 | 0.75 | 0.725 | | | | | | | 27 41 | 27 52 | 27 46,5 | 0.70 | 0.675 | | | | | | | 39 22 | 39 33 | 39 27,5 | 0.65 | 0.630 | | | | | | | 51 2 | 51 15 | 51 8,5 | 0.61 | | | | | | Mean. Correction for Temp. 0°.4. Diff. to 50°. Vibra. in 24 h. at Temp. 50°. **Observation of Coincidences at Port Bowen (1st Series)—continued.** **Morning, June 23rd, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of Vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------|------------------|-----------------------------| | 48.9 | 7 35 | 7 40 | 7 37.5 | 1.15 | 1.110 | s. | vib. | 2.014 | 86224,484 | | 46.0 | 19 13 | 19 20 | 19 16.5 | 1.07 | 1.030 | 700 | 86222,823 | 1.735 | 86224,558 | | 46.0 | 30 53 | 31 00 | 30 56.5 | 0.99 | 0.965 | 703 | 86223,878 | 1.522 | 86225,225 | | 48.2 | 42 36 | 42 42 | 42 39 | 0.94 | 0.910 | 099 | 86222,470 | 1.354 | 86223,824 | | 49.5 | 54 15 | 54 22 | 54 18.5 | 0.88 | 0.850 | 698 | 86222,116 | 1.178 | 86223,648 | | 50.0 | 2 53 | 6 2 | 5 57.5 | 0.82 | 0.800 | 699 | 86222,823 | 1.007 | 86223,830 | | 49.8 | 17 33 | 17 42 | 17 37.5 | 0.75 | 0.725 | 699 | 86222,470 | 0.859 | 86223,329 | | 50.0 | 29 12 | 29 24 | 29 18 | 0.70 | 0.675 | 699 | 86222,470 | 0.745 | 86223,215 | | 50.0 | 40 51 | 41 2 | 40 56.5 | 0.65 | 0.630 | 700 | 86222,823 | 0.649 | 86223,472 | | 50.2 | 52 31 | 52 43 | 52 37 | 0.61 | | | | | | Mean. 86223,895 Correction for Temp. 1°.14. —0.482 Vibrations in 24 h. at Temp. 50°. 86223,413 **Forenoon, 23rd June, 1825, Port Bowen.** Clock gaining at a mean rate 69°.88. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of Vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------|------------------|-----------------------------| | 49.5 | 9 18 | 18 44 | 18 42.5 | 1.18 | 1.135 | 697 | 86221,760 | 2.106 | 86223,866 | | 49.0 | 30 18 | 30 24 | 30 21 | 1.09 | 1.050 | 699 | 86222,470 | 1.803 | 86224,273 | | 48.2 | 41 57 | 42 2 | 41 59.5 | 1.01 | 0.975 | 699 | 86222,470 | 1.554 | 86224,024 | | 48.5 | 53 36 | 53 44 | 53 40 | 0.94 | 0.910 | 701 | 86223,176 | 1.354 | 86224,350 | | 48.8 | 10 5 | 5 24 | 5 20.5 | 0.88 | 0.850 | 700 | 86222,823 | 1.178 | 86224,001 | | 49.0 | 16 57 | 17 4 | 17 00.5 | 0.82 | 0.800 | 700 | 86222,823 | 1.020 | 86223,843 | | 49.0 | 28 37 | 28 45 | 28 41 | 0.76 | 0.735 | 700 | 86222,823 | 0.883 | 86223,706 | | 48.8 | 40 17 | 40 27 | 40 22 | 0.71 | 0.685 | 702 | 86223,527 | 0.766 | 86224,293 | | 48.8 | 51 59 | 52 10 | 52 4.5 | 0.66 | 0.640 | 703 | 86223,878 | 0.670 | 86224,373 | | 48.9 | 11 34 | 3 52 | 3 47 | 0.62 | | | | | | Mean. 86224,120 Correction for Temp. 1°.15. —0.486 Vibrations in 24 h. at Temp. 50°. 86223,634 MDCCCXXVI. Lieutenant Foster's account of Table I. (First Series.) Time by the Clock of Transits of Stars at Port Bowen, Prince Regent's Inlet, June 1825. | Stars | 14th. | 16th. | 18th. | 19th. | 20th. | 22d. | 23d. | |------------------------|-------|-------|-------|-------|-------|------|------| | Arcturus | h. m. s. | h. m. s. | h. m. s. | 8 8 27,51 | 8 5 41,67 | 8 0 9,52 | 7 57 23,66 | | Arcturus 2d & 3d wires | ....... | 8 16 33,03 | ....... | 8 8 13,71 | 8 5 27,95 | 7 59 55,92 | 7 57 9,94 | | Arcturus 3d wire | 8 22 19,38 | 8 16 46,79 | ....... | 8 8 27,22 | 8 5 41,46 | 8 00 9,56 | 7 57 23,70 | | Arcturus 3d, 4th, 5th w. | 8 22 46,90 | ....... | ....... | 8 8 54,91 | 8 6 8,98 | 8 00 36,91 | 7 57 51,05 | | Arcturus 5th wire | 8 23 14,42 | ....... | 8 12 8,93 | 8 9 22,26 | 8 6 36,5 | 8 1 435 | 7 58 18,24 | | α Lyra | 12 45 9,33 | ....... | 12 34 4,02 | 12 31 17,73 | 12 28 31,32 | 12 22 59,16 | 12 22 59,16 | Table II. Transits of the Sun. Time by Clock at the moment of Mean Noon. | 15th. | 17th. | 18th. | 19th. | 21st. | 22d. | 23d. | |-------|-------|-------|-------|-------|------|------| | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | | 11 47 41,29 | 11 50 00,78 | 11 51 10,52 | 11 52 20,07 | 11 54 39,86 | 11 55 49,45 | 11 56 59,66 | From these two Tables, which are formed from the Transit Table, the following rates for the clock, contained in Tables III. and IV. have been computed. Those in Table III. by dividing the difference between the times of transit of each star, on the successive days as given in Table I. by the interval in days, subtracting the quotient from $3^m 55^s.91$, the acceleration in one day, and applying a correction to the remainder, for the change in $AR$ of each star during the interval of their respective successive transits, to obtain the rate in a sidereal day. Those in Table IV. by comparing the time by the clock at the moment of mean noon of each day, as shown in Table II. with that on each succeeding day, and dividing the difference by the number of days in the interval, by which the rate in a mean solar day for 21 separate intervals has been obtained. experiments made with an invariable pendulum. Table III. Rate of the Clock by the Stars. | June 1825 | From 14 to 16 | From 14 to 18 | From 14 to 19 | From 14 to 20 | From 14 to 23 | From 14 to 19 | From 16 to 20 | From 16 to 22 | From 16 to 23 | From 16 to 19 | From 16 to 20 | From 16 to 22 | From 16 to 23 | |-----------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------| | Arcumns 2d & d | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 3d wire | 69,63 | 69,52 | 69,60 | 69,67 | 69,72 | 69,48 | 69,65 | 69,74 | 69,76 | 69,75 | 69,71 | 69,78 | 69,75 | | 5 wire | 69,55 | 69,58 | 69,57 | 69,63 | 69,67 | 69,57 | 69,63 | 69,67 | 69,72 | 69,60 | 69,67 | 69,72 | 69,60 | | a Lyra | 69,53 | 69,57 | 69,56 | 69,58 | 69,57 | 69,58 | 69,58 | 69,57 | 69,56 | 69,58 | 69,57 | 69,58 | 69,57 | | Mean proportion for rate in 3° 56′ | 69,53 | 69,57 | 69,56 | 69,58 | 69,57 | 69,58 | 69,58 | 69,57 | 69,56 | 69,58 | 69,57 | 69,58 | 69,57 | | Rate in a mean solar day | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | +0,19 | Table IV. Rate of the Clock by the Sun. | From 15 to 17 | From 15 to 19 | From 15 to 21 | From 15 to 23 | From 17 to 18 | From 17 to 21 | From 17 to 23 | From 18 to 19 | From 18 to 21 | From 18 to 23 | From 18 to 19 | From 18 to 21 | From 18 to 23 | |---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------|---------------| | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 69,74 | 69,74 | 69,76 | 69,74 | 69,80 | 69,74 | 69,64 | 69,77 | 69,73 | 69,81 | 69,55 | 69,78 | 69,73 | | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 69,74 | 69,74 | 69,76 | 69,74 | 69,80 | 69,74 | 69,64 | 69,77 | 69,73 | 69,81 | 69,55 | 69,78 | 69,73 | | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 69,74 | 69,74 | 69,76 | 69,74 | 69,80 | 69,74 | 69,64 | 69,77 | 69,73 | 69,81 | 69,55 | 69,78 | 69,73 | | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 69,74 | 69,74 | 69,76 | 69,74 | 69,80 | 69,74 | 69,64 | 69,77 | 69,73 | 69,81 | 69,55 | 69,78 | 69,73 | | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | S. | | 69,74 | 69,74 | 69,76 | 69,74 | 69,80 | 69,74 | 69,64 | 69,77 | 69,73 | 69,81 | 69,55 | 69,78 | 69,73 | (Gaining) ### Table V. (1st Series.) Vibrations of the Pendulum at Port Bowen, computed at the mean rate of the Clock, viz. 86469.88 vibrations in a mean solar day. | Date | Time of the Day | Barometer | Therm. | Disappearance | Mean of Disap. & Re-appearance | |------|-----------------|-----------|--------|---------------|-------------------------------| | June 14th | Night | 29.918 | 50.83 | 86223.637 | 86223.837 | | | Morning | 29.922 | 48.87 | 86223.702 | 86223.840 | | | Forenoon | 29.906 | 49.95 | 86223.886 | 86224.004 | | | Afternoon | 29.857 | 46.50 | 86223.612 | 86223.690 | | | Night | 29.835 | 46.53 | 86223.637 | 86223.812 | | June 15th | Morning | 29.836 | 47.80 | 86223.430 | 86223.548 | | | Forenoon | 29.843 | 49.28 | 86224.541 | 86224.658 | | | Afternoon | 29.868 | 49.98 | 86223.729 | 86223.886 | | | Night | 29.859 | 49.10 | 86223.556 | 86223.714 | | June 16th | Morning | 29.859 | 46.00 | 86223.374 | 86223.491 | | | Forenoon | 29.864 | 50.45 | 86223.996 | 86224.114 | | | Afternoon | 29.882 | 52.25 | 86223.991 | 86224.130 | | | Night | 29.905 | 51.62 | 86223.751 | 86223.949 | | June 17th | Morning | 29.908 | 51.37 | 86223.514 | 86223.713 | | | Forenoon | 29.946 | 51.25 | 86223.980 | 86224.079 | | | Afternoon | 29.965 | 52.00 | 86223.998 | 86224.136 | | | Night | 29.964 | 51.15 | 86223.770 | 86223.869 | | June 18th | Morning | 29.956 | 51.14 | 86223.595 | 86223.733 | | | Forenoon | 29.877 | 51.87 | 86223.946 | 86224.086 | | | Afternoon | 29.842 | 52.12 | 86224.035 | 86224.134 | | | Night | 29.819 | 52.07 | 86223.842 | 86224.000 | | June 19th | Morning | 29.813 | 51.77 | 86223.720 | 86223.956 | | | Forenoon | 29.813 | 50.82 | 86223.928 | 86224.027 | | | Afternoon | 29.819 | 50.30 | 86223.768 | 86223.867 | | | Night | 29.820 | 54.35 | 86223.634 | 86223.773 | | June 20th | Morning | 29.766 | 50.06 | 86223.775 | 86223.845 | | | Forenoon | 29.767 | 49.75 | 86223.653 | 86223.791 | | | Afternoon | 29.739 | 52.02 | 86223.847 | 86224.084 | | | Night | 29.735 | 50.56 | 86223.702 | 86223.860 | | June 21st | Morning | 29.735 | 50.56 | 86223.702 | 86223.860 | | | Forenoon | 29.759 | 48.77 | 86223.412 | 86223.510 | | | Afternoon | 29.755 | 48.27 | 86223.418 | 86223.594 | | | Night | 29.755 | 49.60 | 86223.613 | 86223.810 | | June 22nd | Morning | 29.749 | 48.86 | 86223.413 | 86223.550 | | | Forenoon | 29.767 | 48.85 | 86223.634 | 86223.772 | Mean: 29.844 | 50.15 | 86223.736 | 86223.878 Table VI. By the Stars. | June, 1825. | Computed vibrations of the pendulum in 24 h. the clock gaining 694.88 at a mean rate in a mean solar day. | |------------|--------------------------------------------------------------------------------------------------| | From | To | Disappearance. | Mean of Dis. and Re-app. | Observed rate of the clock by Star Transit. | Correct number of vibrations made by the pendulum in a mean solar day at temp. 50°. | |------------|----------------------------------------------------|----------------|--------------------------|---------------------------------------------|---------------------------------------------------------------------------------| | 14th Night | 16th Night | 86223,748 | 86223,888 | 69.82 | 86223,688 | | | 18th | 86223,771 | 86223,910 | 69.76 | 86223,651 | | | 19th | 86223,787 | 86223,925 | 69.73 | 86223,657 | | | 20th | 86223,783 | 86223,922 | 69.77 | 86223,673 | | | 22nd | 86223,750 | 86223,892 | 69.84 | 86223,710 | | | 23rd | 86223,736 | 86223,878 | 69.88 | 86223,736 | | 16th Night | 19th Night | 86223,796 | 86223,934 | 69.67 | 86223,586 | | | 20th | 86223,788 | 86223,928 | 69.84 | 86223,748 | | | 22nd | 86223,742 | 86223,886 | 69.93 | 86223,792 | | | 23rd | 86223,726 | 86223,869 | 69.95 | 86223,796 | | 18th Night | 19th Night | 86223,838 | 86223,964 | 69.73 | 86223,688 | | | 20th | 86223,804 | 86223,938 | 69.77 | 86223,604 | | | 22nd | 86223,728 | 86223,871 | 69.90 | 86223,748 | | | 23rd | 86223,706 | 86223,848 | 69.95 | 86223,776 | | 19th Night | 20th Night | 86223,778 | 86223,925 | 69.97 | 86223,868 | | | 22nd | 86223,693 | 86223,843 | 69.84 | 86223,653 | | | 23rd | 86223,668 | 86223,817 | 70.06 | 86223,848 | | 20th Night | 22nd Night | 86223,679 | 86223,829 | 70.02 | 86223,819 | | | 23rd | 86223,655 | 86223,803 | 70.09 | 86223,865 | | 22nd Night | 23rd | 86223,553 | 86223,711 | 70.22 | 86223,893 | Mean. 86223,744 86223,887 Sum of Factors 127,5 ### Table VII. #### By the Sun. | June 1825 | Computed vibrations of the pendulum in 24 h. the clock gaining 69°.88 at a mean rate in a mean solar day. | Observed rate of transits. | Correct number of vibrations made by the pendulum in a mean solar day at temp. 50°. | |-----------|-------------------------------------------------------------------------------------------------|--------------------------|----------------------------------------------------------------------------------| | From | To | Disappear. | Mean of Dis. and Re-app. | Observed rate of transits. | Correct for diff. of observed rate and 69°.88. | Mean of Dis. and Re-app. | No. of stars observed. | Interval of Transits. | Factors. | |-----------|---------------------------------------------------|--------------------------|--------------------------|--------------------------|-----------------------------------------------|--------------------------|------------------------|----------------------|---------| | 15th Aft | 17th For | 86223,734 | 86223,864 | 69.74 | 0.14 | 86223,594 | 86223,724 | 2 | 2 | 4 | | | 18th | 86223,759 | 86223,899 | 69.74 | 0.14 | 86223,619 | 86223,759 | 2 | 3 | 6 | | | 19th | 86223,776 | 86223,913 | 69.69 | 0.19 | 86223,586 | 86223,723 | 2 | 4 | 8 | | | 21st | 86223,788 | 86223,922 | 69.76 | 0.12 | 86223,668 | 86223,802 | 2 | 6 | 12 | | | 22d | 86223,768 | 86223,906 | 69.74 | 0.14 | 86223,628 | 86223,766 | 2 | 7 | 14 | | | 23d | 86223,736 | 86223,877 | 69.80 | 0.08 | 86223,656 | 86223,797 | 2 | 8 | 16 | | 17th Aft | 18th For | 86223,809 | 86223,908 | 69.74 | 0.14 | 86223,660 | 86223,828 | 2 | 1 | 2 | | | 19th | 86223,818 | 86223,962 | 69.64 | 0.24 | 86223,578 | 86223,722 | 2 | 2 | 4 | | | 21st | 86223,816 | 86223,953 | 69.77 | 0.11 | 86223,706 | 86223,843 | 2 | 4 | 8 | | | 22d | 86223,782 | 86223,923 | 69.73 | 0.15 | 86223,632 | 86223,773 | 2 | 5 | 10 | | | 23d | 86223,730 | 86223,881 | 69.81 | 0.07 | 86223,606 | 86223,811 | 2 | 6 | 12 | | 18th Aft | 19th For | 86223,827 | 86223,956 | 69.55 | 0.33 | 86223,497 | 86223,626 | 2 | 1 | 2 | | | 21st | 86223,819 | 86223,948 | 69.78 | 0.10 | 86223,719 | 86223,848 | 2 | 3 | 6 | | | 22d | 86223,775 | 86223,911 | 69.73 | 0.15 | 86223,625 | 86223,761 | 2 | 4 | 8 | | | 23d | 86223,721 | 86223,863 | 69.83 | 0.05 | 86223,671 | 86223,813 | 2 | 5 | 10 | | 19th Aft | 21st For | 86223,815 | 86223,943 | 69.89 | 0.01 | 86223,825 | 86223,953 | 2 | 2 | 4 | | | 22d | 86223,756 | 86223,895 | 69.79 | 0.09 | 86223,666 | 86223,805 | 2 | 3 | 6 | | | 23d | 86223,693 | 86223,838 | 69.90 | 0.02 | 86223,713 | 86223,858 | 2 | 4 | 8 | | 21st Aft | 22d For | 86223,653 | 86223,811 | 69.59 | 0.29 | 86223,303 | 86223,521 | 2 | 1 | 2 | | | 23d | 86223,586 | 86223,746 | 69.90 | 0.02 | 86223,606 | 86223,766 | 2 | 2 | 4 | | 22d Aft | 23d For | 86223,519 | 86223,681 | 70.21 | 0.33 | 86223,849 | 86224,011 | 2 | 1 | 2 | **Mean** | 86223,645 | 86223,786 | Sum of Factors | 148 | The number of vibrations made by the pendulum in 24 mean solar hours, as obtained by the disappearance of the white disk, from rates deduced by the transits of stars, is 86223,744, and by the sun 86223,645. And of those resulting from the mean of disappearance and re-appearance by the stars, is 86223,877, and by the sun 86223,786; but the sums of the factors being respectively 127,5, and 148, the mean number of vibrations in 24 hours is 86223,659 by the observation of disappearance, and 86223,800 by the mean of disappearance and re-appearance. The mean height of the barometer was 29,844 inches, and the mean temp. 50°.15; whence it appears that the specific gravity of the pendulum was to that of air, as 7000,6 to 1, which gives 67.158 as a correction additive for the buoyancy of the atmosphere. The ball of the pendulum was found by levelling to be 121,04 feet above low water (neap tides), the correction for which by the duplicate ratio of distances from the earth's centre (3950,858 miles) is, 0°.500 in 24 hours. And as the station was the tabular surface of a bed of secondary limestone, I suppose the proper multiplier is \(\frac{66}{105}\), which will give 0°.330 for the correction to be added due to this elevation. These corrections being applied to the number of vibrations before found, will give the number of vibrations that would have been made by the pendulum in a mean solar day, in vacuo at the level of the sea, the temperature being 50° of Fahrenheit at Port Bowen, in latitude* 73° 13' 39".4 N, longitude 88° 54' 48" W, and are as follows: By the observation of disappearance - 86230,147 By the mean of disappearance and re-appear. 86230,288 The state of the ice in the offing being such, as to indicate no immediate prospect of the ships leaving Port Bowen, I gladly availed myself of Captain Parry's permission to pursue these observations by another series; the difference between the results of which, and those of the first series, being only 0.105 of a vibration in 24 hours, affords, it is presumed, * The elements of the observations for the latitude, and longitude, are given in the Appendix to the Narrative of Captain Parry's Third Voyage for the Discovery of a North-West Passage. Lieutenant Foster's account of a satisfactory proof, that no material error in the rate of the clock is to be feared, from the limited number of transits of stars, to which I was confined during the experiments. The following are the observations of the Second Series. Experiment II.—Second Series at Port Bowen, July 1825. Comparisons of Chronometer No. I. with the Clock. | Date | Chronometer | Clock | Difference | |------------|-------------|-------|------------| | Noon 6th. | h. m. s. | h. m. s. | h. m. s. | | P. M. | 2 16 23,5 | 9 17 00 | 4 59 23,5 | | | 2 26 23 | 9 27 00 | 4 59 23 | | | 9 21 33,5 | 4 22 30 | 4 59 3,5 | | | 9 32 3 | 4 33 00 | 4 59 3 | | | 1 37 51,5 | 8 39 00 | 4 58 51,5 | | | 1 48 51 | 8 50 00 | 4 58 51 | | P. M. 7th. | 9 19 56 | 4 22 00 | 4 57 56 | | | 9 30 55,5 | 4 33 00 | 4 57 55,5 | | | 1 35 44 | 8 38 00 | 4 57 44 | | | 1 46 43,5 | 8 49 00 | 4 57 43,5 | | Noon 8th. | 2 16 8 | 9 19 00 | 4 57 8 | | | 2 27 7,5 | 9 30 00 | 4 57 7,5 | | P. M. | 9 11 48,5 | 4 15 00 | 4 56 48,5 | | | 9 22 48 | 4 26 00 | 4 56 48 | | | 1 29 36,5 | 8 33 00 | 4 56 36,5 | | | 1 51 35,5 | 8 55 00 | 4 56 35,5 | | Noon 9th. | 2 17 00,5 | 9 21 00 | 4 56 0,5 | | | 2 28 00 | 9 32 00 | 4 56 00 | | P. M. | 9 4 41,5 | 4 9 00 | 4 55 41,5 | | | 9 15 41 | 4 20 00 | 4 55 41 | | | 1 32 29 | 8 37 00 | 4 55 29 | | | 1 42 28,5 | 8 47 00 | 4 55 28,5 | | Noon 10th. | 2 14 53 | 9 20 00 | 4 54 53 | | | 2 24 52,5 | 9 30 00 | 4 54 52,5 | | P. M. | 8 58 34 | 4 4 00 | 4 54 34 | | | 9 19 33 | 4 25 00 | 4 54 33 | | | 1 25 21,5 | 8 31 00 | 4 54 21,5 | | | 1 35 21 | 8 41 00 | 4 54 21 | | Date | Stars | 1st Wire observed | 1st Wire corrected | 2nd Wire | 3rd Wire | 4th Wire | 5th Wire | Mean Chron. | Comparison of Ohio, with Clock | Mean Clock. | Clock at mean Noon. | |------------|----------------|-------------------|-------------------|----------|----------|----------|----------|-------------|--------------------------------|-------------|---------------------| | July 6th | O's 1st Limb | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | | Noon | | 2 18 4 | 2 20 21 | 2 19 13 26 | 9 23 59 5 | 9 19 56 5 | 9 19 56 5 | 9 19 56 5 | 9 19 56 5 | 9 19 56 5 | 9 19 56 5 | 9 19 56 5 | | P. M. | Arcturus | | | | | | | | | | | | P. M. 7th | O's 1st Limb | | | | | | | | | | | | Noon | | | | | | | | | | | | | 8th | Arcturus | | | | | | | | | | | | Noon | O's 1st Limb | | | | | | | | | | | | P. M. | Arcturus | | | | | | | | | | | | 9th | O's 1st Limb | | | | | | | | | | | | Noon | | | | | | | | | | | | | P. M. 9th | Arcturus | | | | | | | | | | | | 10th | O's 1st Limb | | | | | | | | | | | | Noon | | | | | | | | | | | | | P. M. | Arcturus | | | | | | | | | | | MDCCCXXVI. ### Observation of Coincidences at Port Bowen (2nd Series). **P. M. July 6, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. in 24 h., cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 50.6 | 10 31 36 | 31 39 | | | | | | | | | 50.9 | 42 10 42 | 15 42 12.5 | | | | | | | | | 51.0 | 53 46 53 | 51 48.5 | | | | | | | | | 50.9 | 11 5 22 | 5 27 | | | | | | | | | 50.5 | 16 59 17 | 7 17 3 | | | | | | | | | 50.3 | 28 36 28 | 45 28 40.5 | | | | | | | | | 50.1 | 40 14 40 | 23 40 18.5 | | | | | | | | | 50.1 | 51 54 52 | 3 51 58.5 | | | | | | | | | 50.5 | 12 3 32 | 3 43 | | | | | | | | | 51.0 | 15 11 15 | 22 15 16.5 | | | | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 0°.59.** **Vib. in 24 h. at Temp. 50°.** --- **P. M. July 6, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. in 24 h., cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|--------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 51.0 | 12 32 4 | 32 7 | | | | | | | | | 50.6 | 43 39 43 | 44 43 41.5 | | | | | | | | | 50.5 | 55 10 55 | 21 55 18.5 | | | | | | | | | 50.3 | 1 6 52 | 6 59 | | | | | | | | | 50.8 | 30 8 30 | 15 30 11.5 | | | | | | | | | 51.2 | 41 44 41 | 53 41 48.5 | | | | | | | | | 51.0 | 53 23 53 | 33 43 28 | | | | | | | | | 50.9 | 2 5 1 | 5 11 | | | | | | | | | 50.8 | 16 40 16 | 51 16 45.5 | | | | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 0°.74.** **Vibra. in 24 h. at Temp. 50°.** ## Observation of Coincidences at Port Bowen (2nd Series) — continued. **A.M. July 7, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.8 | 4 7 26 | 7 29 | | 1.16 | 1.120 | | | | | | 52.2 | 18 59 | 19 4 | | 1.08 | 1.040 | | | | | | 52.9 | 30 33 | 30 39 | | 1.00 | 0.965 | | | | | | 53.9 | 42 7 | 42 13 | | 0.93 | 0.900 | | | | | | 53.5 | 53 42 | 53 49 | | 0.87 | 0.845 | | | | | | 53.2 | 5 16 | 5 24 | | 0.82 | 0.795 | | | | | | 53.0 | 16 52 | 17 1 | | 0.77 | 0.745 | | | | | | 52.0 | 28 29 | 28 36 | | 0.72 | 0.695 | | | | | | 52.2 | 40 3 | 40 15 | | 0.67 | 0.645 | | | | | | 52.6 | 51 40 | 51 52 | | 0.62 | 0.645 | | | | | Mean. Correction for Temp. 2°.83. Vibrations in 24 h. at Temp. 50°. --- **A.M. July 7, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 53.8 | 6 32 28 | 32 31 | | 1.18 | 1.140 | | | | | | 53.5 | 44 00 | 45 5 | | 1.10 | 1.060 | | | | | | 53.5 | 55 32 | 55 37 | | 1.02 | 0.985 | | | | | | 54.0 | 7 7 6 | 7 12 | | 0.95 | 0.915 | | | | | | 54.0 | 18 39 | 18 47 | | 0.88 | 0.850 | | | | | | 54.0 | 30 13 | 30 22 | | 0.82 | 0.795 | | | | | | 54.0 | 41 48 | 41 57 | | 0.77 | 0.745 | | | | | | 54.0 | 53 22 | 53 31 | | 0.72 | 0.695 | | | | | | 53.6 | 8 4 58 | 5 7 | | 0.67 | 0.650 | | | | | | 53.1 | 16 33 | 16 43 | | 0.63 | 0.650 | | | | | Mean. Correction for Temp. 3°.75. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (2nd Series) — continued. **P.M. July 7, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc | Vibra. in 24 h. cor. for Arc | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|----------------------------|--------------------------|----------------|---------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.8 | 10 28 44 | 28 47 | | 1.16 | 1.120 | s. | vib. | | | | | | | | | | | | | | | 52.6 | 40 17 | 40 21 | | 1.08 | 1.045 | 693 | 693.5 | | | | | | | | | | | | | | | 52.7 | 51 51 | 51 56 | | 1.01 | 0.975 | 694 | 694.5 | | | | | | | | | | | | | | | 52.2 | 11 3 26 | 3 31 | | 0.94 | 0.905 | 695 | 695 | | | | | | | | | | | | | | | 52.0 | 15 00 | 15 7 | | 0.87 | 0.845 | 694 | 694 | | | | | | | | | | | | | | | 52.5 | 26 36 | 26 43 | | 0.82 | 0.790 | 696 | 696 | | | | | | | | | | | | | | | 53.0 | 38 12 | 38 21 | | 0.76 | 0.735 | 697 | 697 | | | | | | | | | | | | | | | 53.0 | 49 49 | 49 57 | | 0.71 | 0.680 | 695 | 695.5 | | | | | | | | | | | | | | | 53.1 | 12 1 4 | 1 33 | | 0.65 | 0.635 | 696 | 696 | | | | | | | | | | | | | | | 53.1 | 13 00 | 13 11 | | 0.62 | | | | | | Mean. Correction for Temp. 27°. Vibrations in 24 h. at Temp. 50°. --- **P.M. July 7, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc | Vibra. in 24 h. cor. for Arc | |-------|----------------------|----------------------|----------------------------------------|-----------------|---------|----------------------------|--------------------------|----------------|---------------------------| | | h. m. s. | m. s. | | | | | | | | | 52.8 | 1 6 40 | 6 44 | | 1.16 | 1.120 | 694 | 694.5 | | | | | | | | | | | | | | | 52.5 | 18 14 | 18 19 | | 1.08 | 1.040 | 693 | 693.5 | | | | | | | | | | | | | | | 53.0 | 29 47 | 29 53 | | 1.00 | 0.970 | 694 | 694 | | | | | | | | | | | | | | | 53.5 | 41 21 | 41 27 | | 0.94 | 0.900 | 695 | 695.5 | | | | | | | | | | | | | | | 52.8 | 52 56 | 53 3 | | 0.86 | 0.830 | 696 | 696 | | | | | | | | | | | | | | | 52.7 | 2 4 32 | 4 39 | | 0.80 | 0.775 | 695 | 695.5 | | | | | | | | | | | | | | | 52.6 | 16 7 | 16 15 | | 0.75 | 0.725 | 694 | 694 | | | | | | | | | | | | | | | 53.7 | 27 41 | 27 51 | | 0.70 | 0.675 | 695 | 695.5 | | | | | | | | | | | | | | | 53.8 | 39 16 | 39 27 | | 0.65 | 0.630 | 696 | 696 | | | | | | | | | | | | | | | 53.5 | 50 52 | 51 3 | | 0.61 | | | | | | Mean. Correction for Temp. 3°.09. Vibra. in 24 h. at Temp. 50°. ## Observation of Coincidences at Port Bowen (2nd Series) — continued. **A. M. July 8, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|----------------|--------------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.8 | 4 12 42 | 12 47 | | 1.16 | 1.120 | | | | | | 49.9 | 24 18 | 24 23 | | 1.08 | 1.045 | | | | | | 50.5 | 35 54 | 36 00 | | 1.01 | 0.975 | | | | | | 50.8 | 47 39 | 47 37 | | 0.94 | 0.905 | | | | | | 50.5 | 59 6 | 59 14 | | 0.87 | 0.840 | | | | | | 50.3 | 5 10 44 | 10 53 | | 0.81 | 0.780 | | | | | | 50.0 | 22 22 | 22 31 | | 0.75 | 0.730 | | | | | | 49.9 | 34 1 | 34 13 | | 0.71 | 0.685 | | | | | | 49.8 | 45 40 | 45 51 | | 0.66 | 0.635 | | | | | | 50.0 | 57 20 | 57 31 | | 0.61 | 0.635 | | | | | Mean. Correction for Temp. 0°.15. Vibra. in 24 h. at Temp. 50°. --- **A. M. July 8, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|----------------|--------------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.9 | 6 49 8 | 49 11 | | 1.16 | 1.120 | | | | | | 49.5 | 7 00 44 | 00 49 | | 1.08 | 1.045 | | | | | | 49.2 | 12 20 12 27 | 12 23 5 | | 1.01 | 0.975 | | | | | | 49.1 | 23 59 24 4 | 22 15 | | 0.94 | 0.905 | | | | | | 49.2 | 35 37 35 45 | 35 41 | | 0.87 | 0.840 | | | | | | 49.2 | 47 16 47 23 | 47 19 5 | | 0.81 | 0.780 | | | | | | 49.2 | 58 54 59 3 | 54 58 5 | | 0.75 | 0.730 | | | | | | 49.4 | 8 10 35 | 10 44 | | 0.71 | 0.685 | | | | | | 49.4 | 22 14 22 24 | 22 19 | | 0.66 | 0.635 | | | | | | 49.5 | 33 55 34 5 | 34 00 | | 0.61 | 0.635 | | | | | Mean. Correction for Temp. 0°.64. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (2nd Series) — continued. **P.M. July 8, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 51° | 10 22 15 | 22 19 | | | | | | | | | 50° | 33 50 | 33 55 | | | | | | | | | 50° | 45 26 | 45 33 | | | | | | | | | 50° | 57 3 | 57 10 | | | | | | | | | 50° | 11 8 40 | 8 49 | | | | | | | | | 50° | 20 18 | 20 27 | | | | | | | | | 50° | 31 58 | 32 6 | | | | | | | | | 50° | 43 37 | 43 47 | | | | | | | | | 50° | 55 16 | 55 27 | | | | | | | | | 49° | 12 6 54 | 7 8 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.36. Vibra. in 24 h. at Temp. 50°. --- **P.M. July 8, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct for Arc. | Observed vibra. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 50° | 12 35 36 | 35 39 | | | | | | | | | 50° | 47 12 47 | 47 16 | | | | | | | | | 50° | 58 48 | 58 53 | | | | | | | | | 50° | 1 10 25 | 10 32 | | | | | | | | | 50° | 10 28 5 | 10 28 5 | | | | | | | | | 50° | 22 2 22 | 22 5 5 | | | | | | | | | 50° | 33 40 | 33 48 | | | | | | | | | 50° | 33 44 | 33 44 | | | | | | | | | 50° | 45 18 | 45 27 | | | | | | | | | 50° | 56 56 | 57 1 | | | | | | | | | 50° | 2 8 36 | 8 47 | | | | | | | | | 50° | 20 16 | 20 27 | | | | | | | | Mean. Diff. to 50°. Correction for Temp. 0°.49. Vibra. in 24 h. at Temp. 50°. **Observation of Coincidences at Port Bowen (2nd Series) —continued.** A.M. July 9, 1825, Port Bowen. Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 51.0 | 6 44 31 | 44 35 | | 1.19 | 1.145 | | | | | | 51.0 | 56 6 | 56 11 | | 1.10 | 1.02 | | | | | | 50.8 | 7 7 42 | 7 47 | | 1.02 | 0.985 | | | | | | 51.0 | 19 18 | 19 25 | | 0.95 | 0.915 | | | | | | 51.1 | 30 56 | 31 2 | | 0.88 | 0.850 | | | | | | 51.0 | 42 33 | 42 40 | | 0.82 | 0.790 | | | | | | 51.0 | 54 11 | 54 18 | | 0.76 | 0.740 | | | | | | 51.8 | 8 5 48 | 5 57 | | 0.72 | 0.695 | | | | | | 52.3 | 17 26 | 17 36 | | 0.67 | 0.645 | | | | | | 52.7 | 29 4 | 29 13 | | 0.62 | | | | | | Mean. Diff. to 50°. Correction for Temp. 1°.37. Vibra. in 24 h. at Temp. 50°. P.M. July 9, 1825, Port Bowen. Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 53.0 | 10 30 19 | 30 21 | | 1.20 | 1.160 | | | | | | 52.6 | 41 51 | 41 56 | | 1.12 | 1.080 | | | | | | 52.7 | 53 27 | 53 31 | | 1.04 | 1.005 | | | | | | 52.6 | 11 5 | 5 8 | | 0.97 | 0.935 | | | | | | 52.6 | 16 36 | 16 43 | | 0.90 | 0.870 | | | | | | 52.7 | 28 12 | 28 20 | | 0.84 | 0.815 | | | | | | 52.8 | 39 48 | 39 56 | | 0.79 | 0.760 | | | | | | 52.8 | 51 25 | 51 33 | | 0.73 | 0.710 | | | | | | 52.9 | 12 3 | 3 10 | | 0.69 | 0.660 | | | | | | 52.8 | 14 38 | 14 48 | | 0.63 | | | | | | Mean. Diff. to 50°. Correction for Temp. 2°.75. Vibra. in 24 h. at Temp. 50°. ### Observation of Coincidences at Port Bowen (2nd Series) — continued. **P. M. July 9, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds by Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------|----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 53.0 | 1 26 10 | 26 13 | | | | | | | | | 53.0 | 37 42 | 37 46 | | | | | | | | | 52.5 | 49 16 | 49 21 | | | | | | | | | 52.3 | 2 00 51 | 00 58 | | | | | | | | | 52.3 | 12 26 | 12 33 | | | | | | | | | 52.7 | 24 2 | 24 9 | | | | | | | | | 53.0 | 35 37 | 35 45 | | | | | | | | | 52.9 | 47 13 | 47 23 | | | | | | | | | 53.0 | 58 50 | 59 00 | | | | | | | | | 53.0 | 3 10 26 | 10 37 | | | | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 2°.77.** **Vibrations in 24 h. at Temp. 50°.** --- **A. M. July 10, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds by Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|-----------------------|----------------------------------------|-----------------|----------|-------------------------------|-------------------------|----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.9 | 5 5 39 | 5 42 | | | | | | | | | 49.8 | 17 15 | 17 20 | | | | | | | | | 49.6 | 28 53 | 28 58 | | | | | | | | | 49.7 | 40 30 | 40 36 | | | | | | | | | 49.9 | 52 8 | 52 16 | | | | | | | | | 49.7 | 6 3 47 | 3 54 | | | | | | | | | 49.5 | 15 26 | 15 35 | | | | | | | | | 50.0 | 27 7 | 27 17 | | | | | | | | | 49.9 | 38 46 | 38 56 | | | | | | | | | 49.4 | 50 26 | 50 37 | | | | | | | | **Mean.** **Diff. to 50°.** **Correction for Temp. 0°.26.** **Vibra. in 24 h. at Temp. 50°.** **Observation of Coincidences at Port Bowen (2nd Series)—continued.** A. M. July 10, 1825, Port Bowen. Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 49.7 | 7 12 18 | 12 22 | | | | | | | | | 50.0 | 23 55 24 oo | 23 57.5 | | | | | | | | | 49.9 | 35 33 | 35 39 | | | | | | | | | 49.8 | 47 11 | 47 18 | | | | | | | | | 50.0 | 58 50 | 58 56 | | | | | | | | | 50.3 | 8 10 29 | 10 37 | | | | | | | | | 50.2 | 22 7 | 22 16 | | | | | | | | | 50.0 | 34 47 | 34 56 | | | | | | | | | 50.0 | 45 27 | 45 37 | | | | | | | | | 50.1 | 57 8 | 57 13 | | | | | | | | Mean. Vibrations in 24 h. at Temp. 50°. 86223,647 86223,765 P. M. July 10, 1825, Port Bowen. Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 50.5 | 10 36 35 | 36 38 | | | | | | | | | 50.5 | 48 12 | 48 16 | | | | | | | | | 50.5 | 59 49 | 59 54 | | | | | | | | | 50.5 | 11 11 27 | 11 33 | | | | | | | | | 50.3 | 23 5 | 23 12 | | | | | | | | | 50.0 | 34 44 | 34 51 | | | | | | | | | 50.0 | 46 23 | 46 31 | | | | | | | | | 50.1 | 58 3 | 58 12 | | | | | | | | | 50.2 | 12 9 45 | 9 53 | | | | | | | | | 50.3 | 21 24 | 21 33 | | | | | | | | Mean. Correction for Temp. o°.29. + 0.123 Vibra. in 24 h. at Temp. 50°. 86223,791 86223,910 MDCCCXXVI. ### Observation of Coincidences at Port Bowen (2nd Series) — continued. **P. M. July 10, 1825, Port Bowen.** Clock gaining at an assumed rate 69°.88 in 24 h. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|-----------------------------| | | h. m. s. | m. s. | m. s. | | | | | | | | 49.8 | 12 56 19 | 56 22 | 56 20.5 | 1.21 | 1.165 | | | | | | 49.8 | 1 7 56 | 8 1 | 7 58.5 | 1.12 | 1.080 | | | | | | 50.0 | 19 34 | 19 38 | 19 36 | 1.04 | 1.010 | | | | | | 50.0 | 31 11 | 31 17 | 31 14 | 0.98 | 0.950 | | | | | | 50.0 | 42 49 | 42 58 | 42 53.5 | 0.92 | 0.885 | | | | | | 50.1 | 54 29 | 54 36 | 54 32.5 | 0.85 | 0.820 | | | | | | 50.5 | 2 0 9 | 6 16 | 6 12.5 | 0.79 | 0.760 | | | | | | 50.7 | 17 46 | 17 55 | 17 50.5 | 0.73 | 0.705 | | | | | | 50.6 | 29 25 | 29 36 | 29 30.5 | 0.68 | 0.655 | | | | | | 50.5 | 41 5 | 41 16 | 41 10.5 | 0.63 | | | | | | Mean. Correction for Temp. o°.20. Vibra. in 24 h. at Temp. 50°. --- ### Table I. (2nd Series.) Times by Clock at Transits of Stars, at Port Bowen, July, 1825. | Stars. | 6th. | 7th. | 8th. | 9th. | 10th. | |--------|------|------|------|------|-------| | | h. m. s. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | | Arcturus | 4 23 42.54 | 4 22 56.58 | 4 20 10.95 | 4 17 24.54 | 4 14 38.80 | | α Lyrae | 8 48 32.41 | 8 45 46.75 | 8 43 00.93 | 8 40 14.81 | 8 37 28.75 | Table II. Transits of Sun. Times by Clock at the moment of Mean Noon. | | 6th. | 8th. | 9th. | 10th. | |-------|------|------|------|-------| | h. m. s. | 9 16 28.54 | 9 18 48.99 | 9 19 59.03 | 9 21 9.36 | Table III. Rates of the Clock by the Stars. (Gaining.) | Stars | From 6 to 7 | From 6 to 8 | From 6 to 9 | From 6 to 10 | From 7 to 8 | From 7 to 9 | From 7 to 10 | From 8 to 9 | From 8 to 10 | From 9 to 10 | |-----------|-------------|-------------|-------------|--------------|-------------|-------------|--------------|-------------|--------------|--------------| | Arcturus | 69.96 | 70.12 | 69.92 | 69.98 | 70.29 | 69.90 | 69.99 | 69.51 | 69.84 | 70.18 | | α Lyrae | 70.25 | 70.16 | 70.04 | 69.99 | 70.09 | 69.93 | 69.91 | 69.79 | 69.81 | 69.85 | | Mean | 70.11 | 70.14 | 69.98 | 69.99 | 70.19 | 69.92 | 69.95 | 69.65 | 69.83 | 70.02 | | Proporta. for rate in 3° 56' | + .19 | + .19 | + .19 | + .19 | + .19 | + .19 | + .19 | + .19 | + .19 | + .19 | | Rate of the Clock, gaining in a mean solar day... | 70.30 | 70.33 | 70.17 | 70.18 | 70.38 | 70.11 | 70.14 | 69.84 | 70.02 | 70.21 | Table IV. Rates of the Clock by the Sun. (Gaining.) | From 6 to 8 | From 6 to 9 | From 6 to 10 | From 8 to 9 | From 8 to 10 | From 9 to 10 | |-------------|-------------|--------------|-------------|--------------|--------------| | s. | 70.22 | 70.16 | 70.20 | 70.04 | 70.18 | 70.33 | ### Lieutenant Foster's account of #### Table V. Second Series. **Vibrations of the Pendulum at Port Bowen, computed at the assumed rate of the Clock, viz. 86469.88 vibrations in a mean solar day.** | Date | Time of the day | Barometer. | Thermom. | Vibrations in 24 h. at Temp. 50°. | |----------|-----------------|------------|----------|----------------------------------| | | | inches. | | Disappearance. Mean of Disap. and Re-ap. | | July 6th | P. M. | 29.755 | 50.59 | 86223.366 86223.524 | | | | 757 | 50.74 | 86223.445 86223.604 | | | A. M. | 29.749 | 52.83 | 86223.451 86223.630 | | | | 742 | 53.75 | 86223.512 86223.652 | | | P. M. | 746 | 52.70 | 86223.473 86223.632 | | | | 756 | 53.09 | 86223.459 86223.599 | | 8th | A. M. | 29.810 | 50.15 | 86223.261 86223.379 | | | | 810 | 49.36 | 86223.282 86223.420 | | | P. M. | 812 | 50.36 | 86223.399 86223.597 | | | | 819 | 50.49 | 86223.530 86223.688 | | 9th | A. M. | 29.812 | 51.37 | 86223.616 86223.715 | | | P. M. | 811 | 52.75 | 86223.699 86223.858 | | | | 804 | 52.77 | 86223.609 86223.769 | | 10th | A. M. | 29.772 | 49.74 | 86223.525 86223.683 | | | | 771 | 50.00 | 86223.647 86223.765 | | | P. M. | 773 | 50.29 | 86223.791 86223.910 | | | | 774 | 50.20 | 86223.703 86223.861 | Mean: 29.781 51.25 86223.516 86223.664 ### Table VI. Second Series. **By the Stars.** | July 1825. | Computed vibrations of the pendulum in 24 h. the clock gaining 69°.88 (assumed rate) in a mean solar day. | |------------|-----------------------------------------------------------------------------------------------------| | From | To | Disappearance. Mean of Disap. and Re-ap. | Observed rate of the clock by Stars transit. | Corrections to vibrations made by the pendulum in a mean solar day at temperature 50°. | | | | | Correct number of vibrations made by the pendulum in a mean solar day at temperature 50°. | | 7th A. M. | 7th P. M. | 86223.474 86223.628 70.30 + 0.420 vih. 86223.894 86224.048 2 1 2 | | | 8th | 86223.421 86223.575 70.33 + 0.450 86223.871 86224.025 2 2 4 | | | 9th | 86223.481 86223.631 70.17 + 0.290 86223.771 86223.921 2 3 6 | | | 10th | 86223.530 86223.677 70.18 + 0.300 86223.830 86223.977 2 4 8 | | 8th A. M. | 8th P. M. | 86223.343 86223.521 70.38 + 0.500 86223.843 86224.021 2 1 2 | | | 9th | 86223.485 86223.632 70.11 + 0.230 86223.715 86223.862 2 2 4 | | | 10th | 86223.551 86223.695 70.14 + 0.260 86223.811 86223.955 2 3 6 | | 9th A. M. | 9th P. M. | 86223.641 86223.781 69.84 - 0.040 86223.601 86223.741 2 1 2 | | | 10th | 86223.656 86223.794 70.02 + 0.140 86223.796 86223.794 2 2 4 | | 10th A. M. | 10th P. M. | 86223.666 86223.805 70.21 + 0.230 86223.896 86224.035 2 1 2 | Mean: 86223.803 86223.938 Sum of Factors 40 Table VII. (2nd Series.) | July, 1825. | Computed vibrations of the pendulum in 24 h, the clock gaining 69°.88 (assumed rate) in a mean solar day. | Correct number of vibrations made by the pendulum in a mean solar day at temperature 50°. | |------------|-------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------| | From | To | Observed rate of the clock by Sun's transit. Corrections to the rate of the clock by Sun's transit. Mean of Disappearance and Re-appearance. | | 6th, P.M. | 8th, A.M. | s. vib. | | | 86223,406 | 70.22 + 0.340 | | | 86223,436 | 70.16 + 0.280 | | | 86223,485 | 70.20 + 0.320 | | | 86223,515 | 70.04 + 0.160 | | | 86223,561 | 70.18 + 0.300 | | | 86223,620 | 70.33 + 0.450 | | 8th, P.M. | 9th, A.M. | | | | 86223,555 | | | | 86223,585 | | | | 86223,634 | | | | 86223,667 | | | | 86223,725 | | | | 86223,769 | | | 9th, P.M. | 10th, A.M. | | | | 86223,746 | | | | 86223,716 | | | | 86223,805 | | | | 86223,675 | | | | 86223,861 | | | | 86224,070 | | | Mean. | | | In this series, the number of vibrations made by the pendulum in 24 hours of mean solar time, as obtained from the observations of the disappearance of the white disk, and employing the rates furnished by the transits of stars, is 86223,803, and by the rates, from the sun's transits 86223,812. By the mean of the observations of the disappearance and re-appearance of the disk, the number of vibrations is 86223,938 by the rates, from the stars' transits, and 86223,964 by the transits of the sun. But the sum of the factors for the stars being 40, and for the sun 26, the mean number of vibrations in 24 hours, by the observation of the disappearance of the white disk is 86223,806, and by the mean of its disappearance and re-appearance 86223,948. If to each of these, we apply the corrections, 0°,330 for elevation, and 6°,116 for the buoyancy of the atmosphere, at the mean pressure 29,781 inches, and temperature 51°,25 of Fahrenheit, we shall arrive at the total number of vibrations which would have been made by the pendulum in a mean solar day, the temperature being 50° of Fahrenheit, in vacuo, at the level of the sea at Port Bowen; and are By the observation of disappearance - - - 86230,252 By the mean of disappearance and re-appearance - 86230,394 By the first series, the total number of vibrations of the pendulum in 24 hours was By the observation of disappearance - - - 86230,147 By the mean of disappearance and re-appearance 86230,288 Lieutenant Foster's account of The sums of the factors, however, being 275,5 in this series, and only 66 in the second, we obtain for the final number of vibrations at Port Bowen, By the method of disappearance - - 86230,172 By the mean of disappearance and re-app. 86230,313. From the above data and number of vibrations made by the same pendulum from the mean of both series at Greenwich, viz. by the method of disappearance - - 86159,368 and by mean of disappearance and re-app. 86159,500, together with the assumed length of the seconds' pendulum at Greenwich 39,13911 inches; the length of the seconds' pendulum at Port Bowen is found to be nearly 39,203464 inches, by the method of disappearance, and by the mean of disappearance and re-appearance 39,203472 inches; and comparing these with 39,13911 inches, the assumed length in lat. 51° 28' 39" N. as before stated, the diminution of gravity from the pole to the equator will be by the method of disappearance ,0054152, the ellipticity of the earth $\frac{1}{309,13}$, and the length of the equatorial pendulum 39,009805 inches; and by the mean of disappearance and re-appearance, the diminution of gravity from the pole to the equator will be ,0054159, the ellipticity of the earth $\frac{1}{309,19}$, and the length of the equatorial pendulum 39,009789 inches of Sir George Schuckburgh's scale. The length of the pendulum vibrating seconds, not having been determined at Greenwich, but at Mr. Browne's house in London, it must be remembered that the above lengths are not the true lengths of the pendulum, but are merely given for the sake of comparison. experiments made with an invariable pendulum. III. Concluding Series at the Royal Observatory at Greenwich. November 1825. Comparisons of the Clock, with the Observatory Transit Clock. | Date | Time by Clock | Time by the Observatory Clock | Mean Time at Greenwich | Clock Slow of Mean Time | |------------|---------------|------------------------------|------------------------|------------------------| | 7th, A. M. | h. m. s. | h. m. s. | h. m. s. | h. m. s. | | Noon | 2 25 00 | 12 2 31,52 | 8 56 33,44 | 6 31 33,44 | | P. M. | 5 25 00 | 15 3 1,38 | 11 56 34,06 | 6 31 34,06 | | 8th, A. M. | 8 34 00 | 18 12 32,95 | 3 5 34,13 | 6 31 34,13 | | Noon | 2 17 29,93 | 11 59 00,00 | 8 49 6,15 | 6 31 36,22 | | P. M. | 5 33 57,34 | 15 16 00,00 | 0 5 33,85 | 6 31 36,51 | | 9th, A. M. | 8 24 00 | 18 6 30,86 | 2 55 36,74 | 6 31 36,74 | | Noon | 2 23 00 | 12 8 29,77 | 8 54 38,21 | 6 31 38,21 | | P. M. | 5 35 00 | 15 21 1,54 | 0 6 38,40 | 6 31 38,40 | | 10th, A. M.| 8 23 00 | 18 9 29,38 | 2 54 38,60 | 6 31 38,60 | | Noon | 2 25 00 | 12 14 28,64 | 8 56 39,89 | 6 31 39,89 | | P. M. | 5 36 00 | 15 26 00,22 | 0 7 40,06 | 6 31 40,06 | | 11th, A. M.| 8 39 00 | 18 29 30,39 | 3 10 40,14 | 6 31 40,14 | | Noon | 2 36 00 | 12 29 28,47 | 9 7 41,16 | 6 31 41,16 | | P. M. | 5 28 00 | 15 21 56,91 | 11 59 41,32 | 6 31 41,32 | | | 9 13 00 | 19 7 34,24 | 3 44 41,62 | 6 31 41,62 | From the above Table of Comparisons the following, of rates losing, has been deduced. | Times of Comparison | From 7 to 8 | From 7 to 9 | From 7 to 10 | From 7 to 11 | From 8 to 9 | From 8 to 10 | From 8 to 11 | From 9 to 10 | From 9 to 11 | From 10 to 11 | |---------------------|-------------|-------------|--------------|--------------|-------------|--------------|--------------|--------------|--------------|--------------| | A. M. | 2.794 | 2.386 | 2.150 | 1.930 | 1.978 | 1.828 | 1.638 | 1.678 | 1.469 | 1.260 | | Noon | 2.435 | 2.163 | 1.996 | 1.814 | 1.892 | 1.776 | 1.608 | 1.660 | 1.465 | 1.271 | | P. M. | 2.630 | 2.241 | 2.002 | 1.862 | 1.853 | 1.687 | 1.606 | 1.522 | 1.483 | 1.445 | | Rate lost in a mean solar day | 2.62 | 2.26 | 2.05 | 1.87 | 1.91 | 1.76 | 1.62 | 1.62 | 1.47 | 1.32 | ### Observations of Coincidences at Greenwich, November, 1825. Height above the level of the sea 181.5 feet. A.M. November 7th, 1825, Royal Observatory. Clock losing at a mean rate 1.87 per diem. Bar. \( \{ \text{Begs. } 29.121 \text{ mer. } 45^\circ. \} = 29.115 \text{ mean cor. to } 45^\circ. \) temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. | Disap. & Re-ap. | Disappearance. | Mean of Disap. and Re-ap. | | 43.5 | 3 21 00 | 21 5 | | 1.16 | 1.120 | 710 | 710 | . . . . . | vib. | | 43.6 | 32 50 | 32 55 | | 1.08 | 1.040 | 710 | 711 | . . . . . | 2.050 | | 43.8 | 44 40 | 44 47 | | 1.00 | 0.970 | 711 | 711 | . . . . . | 1.769 | | 43.9 | 56 31 | 56 38 | | 0.94 | 0.910 | 710 | 710.5 | . . . . . | 1.538 | | 44.0 | 4 8 21 | 8 29 | | 0.88 | 0.855 | 712 | 712 | . . . . . | 1.353 | | 44.0 | 20 13 | 20 21 | | 0.83 | 0.795 | 711 | 711.5 | . . . . . | 1.194 | | 44.2 | 32 4 | 32 13 | | 0.76 | 0.735 | 712 | 712 | . . . . . | 1.034 | | 44.5 | 43 56 | 44 5 | | 0.71 | 0.685 | 713 | 712.5 | . . . . . | 0.882 | | 44.7 | 55 49 | 55 57 | | 0.66 | 0.640 | 712 | 713 | . . . . . | 0.766 | | 44.9 | 5 7 41 | 7 51 | | 0.62 | | | | . . . . . | 0.671 | Means. | 711.11 | 711.5 | 86155.135 | 86155.268 | 1.251 | 86156.386 | 86156.519 | P.M. November 7th, 1825, Royal Observatory. Clock losing at a mean rate 1.87 per diem. Bar. \( \{ \text{Begs. } 29.125 \text{ mer. } 45^\circ.5. \} = 29.126 \text{ mean cor. to } 45^\circ.2. \) temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|--------------------------|------------------|-----------------------------| | 46 | 6 29 36 | 29 43 | | 1.16 | 1.120 | 709 | 707.5 | . . . . . | vib. | | 46 | 41 25 | 41 29 | | 1.08 | 1.040 | 706 | 707 | . . . . . | 2.050 | | 46 | 53 11 | 53 17 | | 1.00 | 0.965 | 708 | 708.5 | . . . . . | 1.769 | | 46 | 7 4 59 | 5 6 | | 0.93 | 0.900 | 708 | 708.5 | . . . . . | 1.523 | | 46 | 16 47 | 16 55 | | 0.87 | 0.840 | 709 | 709.5 | . . . . . | 1.324 | | 46.2 | 28 36 | 28 45 | | 0.81 | 0.780 | 709 | 709 | . . . . . | 1.154 | | 46.4 | 40 25 | 40 34 | | 0.75 | 0.720 | 709 | 709 | . . . . . | 0.996 | | 46.3 | 52 14 | 52 25 | | 0.69 | 0.665 | 710 | 710 | . . . . . | 0.846 | | 46.2 | 8 4 4 | 4 15 | | 0.64 | 0.620 | 710 | 711 | . . . . . | 0.722 | | 46.2 | 15 54 | 16 7 | | 0.60 | | | | . . . . . | 0.628 | Means. | 708.667 | 709.0 | 86154.297 | 86154.412 | 1.224 | 86155.521 | 86155.636 | ### Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. A. M. November 8th, 1825, Royal Observatory. Clock losing at a mean rate 1°.87 per diem. Bar. { Begs. 29.251 mer. 39°.5. } = 29.200 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|---------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 40.0 | 3 27 28 | 27 33 | | 27 30.5 | 1.18 | | | | | | 40.2 | 39 20 | 39 25 | | 39 22.5 | 1.09 | | | | | | 40.6 | 51 12 | 51 19 | | 51 15.5 | 1.02 | | | | | | 40.9 | 4 3 6 | 3 13 | | 3 9.5 | 0.95 | | | | | | 41.0 | 14 59 | 15 7 | | 15 3 | 0.88 | | | | | | 41.0 | 26 53 | 27 1 | | 26 57 | 0.82 | | | | | | 41.2 | 38 46 | 38 57 | | 38 51.5 | 0.75 | | | | | | 41.9 | 50 40 | 50 51 | | 50 45.5 | 0.70 | | | | | | 42.1 | 5 2 33 | 2 45 | | 2 39 | 0.65 | | | | | | 42.1 | 14 28 | 14 39 | | 14 33.5 | 0.61 | | | | | Means. | 713,333 | 713,667 | 86155,892 | 86156,005 | 1.258 | 86157,150 | 86157,263 | P. M. November 8th, 1825, Royal Observatory. Clock losing at a mean rate 1°.87 per diem. Bar. { Begs. 29.104 mer. 42°.8. } = 29.058 mean cor. to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|---------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | | | | | | 43.1 | 6 26 34 | 26 40 | | 26 37 | 1.14 | | | | | | 43.2 | 38 24 | 38 28 | | 38 26 | 1.05 | | | | | | 43.2 | 50 12 | 50 19 | | 50 15.5 | 0.98 | | | | | | 43.7 | 7 2 2 | 2 11 | | 2 6.5 | 0.91 | | | | | | 44.0 | 13 52 | 14 1 | | 13 56.5 | 0.85 | | | | | | 44.2 | 25 42 | 25 50 | | 25 46 | 0.80 | | | | | | 44.5 | 37 32 | 37 41 | | 37 36.5 | 0.75 | | | | | | 44.8 | 49 20 | 49 31 | | 49 25.5 | 0.70 | | | | | | 45.0 | 8 1 12 | 1 21 | | 1 16.5 | 0.65 | | | | | | 45.5 | 13 00 | 13 11 | | 13 5.5 | 0.60 | | | | | Means. | 709,556 | 709,833 | 86154,603 | 86154,698 | 1.189 | 86155,792 | 86155,887 | MDCCXXVI. * K ### Observations of Coincidences at Greenwich — continued. Height above the level of the sea 181.5 feet. **A. M. November 9th, 1825, Royal Observatory.** Clock losing at a mean rate 1°.87 per diem. Bar. {Begs. 28,969 mer. 44°.5.} = 28,973 mean cor. {Ends. 29,000 — 46°.0.} to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance | Mean of Disap. and Re-ap. | Mean of Disap. and Re-ap. | | 44.8 | 3 17 52 | 17 57 | 17 54.5 | 1.13 | 1.090 | 706 | 706.5 | | 1.943 | | 44.9 | 29 38 | 29 44 | 29 41 | 1.05 | 1.015 | 704 | 705.5 | | 1.684 | | 45.0 | 41 22 | 41 31 | 41 26.5 | 0.98 | 0.945 | 707 | 706.5 | | 1.461 | | 45.2 | 53 9 | 53 17 | 53 13 | 0.91 | 0.875 | 707 | 707.5 | | 1.250 | | 45.7 | 4 456 | 5 5 | 5 00.5 | 0.84 | 0.810 | 706 | 707 | | 1.072 | | 45.9 | 16 42 | 16 53 | 16 47.5 | 0.78 | 0.755 | 707 | 706.5 | | 0.931 | | 46.0 | 28 29 | 28 39 | 28 34 | 0.73 | 0.705 | 707 | 707.5 | | 0.812 | | 46.1 | 40 16 | 40 27 | 40 21.5 | 0.68 | 0.655 | 708 | 708 | | 0.701 | | 46.5 | 52 4 | 52 15 | 52 9.5 | 0.63 | 0.610 | 706 | 707 | | 0.608 | | 46.8 | 5 350 | 4 3 | 3 36.5 | 0.59 | | | | | | | 45.69 | Means. | | | | | | | | | P. M. November 9th, 1825, Royal Observatory. Clock losing at a mean rate 1°.87 per diem. Bar. {Begs. 29,016 mer. 47°.5.} = 29,023 mean cor. {Ends. 29,050 — 47°.} to temp. of pend. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct. for Arc. | Vibra. in 24 h. cor. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|-----------------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance | Mean of Disap. and Re-ap. | Mean of Disap. and Re-ap. | | 47.7 | 6 25 10 | 25 15 | 25 12.5 | 1.13 | 1.090 | 702 | 702 | | 1.943 | | 47.8 | 36 52 | 36 57 | 36 54.5 | 1.05 | 1.015 | 702 | 704 | | 1.684 | | 47.7 | 48 34 | 48 43 | 48 38.5 | 0.98 | 0.950 | 705 | 704.5 | | 1.476 | | 47.7 | 7 00 19 | 00 27 | 00 23 | 0.92 | 0.885 | 705 | 704.5 | | 1.281 | | 47.6 | 12 4 | 12 11 | 12 7.5 | 0.85 | 0.820 | 705 | 705.5 | | 1.099 | | 47.6 | 23 49 | 23 57 | 23 53 | 0.79 | 0.760 | 705 | 706.5 | | 0.943 | | 47.7 | 35 34 | 35 45 | 35 39.5 | 0.73 | 0.705 | 706 | 706 | | 0.812 | | 47.3 | 47 20 | 47 31 | 47 25.5 | 0.68 | 0.650 | 706 | 707 | | 0.691 | | 47.0 | 59 6 | 59 19 | 59 12.5 | 0.62 | 0.600 | 708 | 707 | | 0.589 | | 47.0 | 8 10 54 | 11 5 | 10 59.5 | 0.58 | | | | | | | 47.51 | Means. | | | | | | | | | experiments made with an invariable pendulum. Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. A. M. November 10th, 1825, Royal Observatory. Clock losing at a mean rate 1°.87 per diem. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|---------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance. | Mean of Disap. and Re-app. | Mean of Disap. and Re-app. | | 44.0 | 3 19 1 | 19 8 | 19 4½ | 1.10 | 1.060 | 706 | 706 | 1.837 | | | 44.0 | 30 47 | 30 54 | 30 50½ | 1.02 | 0.980 | 706 | 706 | 1.572 | | | 44.1 | 42 33 | 42 40 | 42 36½ | 0.94 | 0.910 | 706 | 707 | 1.353 | | | 44.1 | 54 19 | 54 28 | 54 23½ | 0.88 | 0.850 | 707 | 707½ | 1.181 | | | 44.1 | 4 6 6 | 6 16 | 6 11 | 0.82 | 0.790 | 706 | 707½ | 1.021 | | | 44.2 | 17 52 | 18 5 | 17 58½ | 0.76 | 0.740 | 709 | 708 | 0.896 | | | 44.3 | 29 41 | 29 52 | 29 46½ | 0.72 | 0.700 | 706 | 707½ | 0.801 | | | 44.4 | 41 27 | 41 41 | 41 34 | 0.68 | 0.655 | 708 | 708½ | 0.702 | | | 44.5 | 53 15 | 53 30 | 53 22½ | 0.63 | 0.605 | 710 | 709 | 0.598 | | | 44.8 | 5 5 5 | 5 18 | 5 11½ | 0.58 | | | | | | Means. | 707,111 | 707,444 | 86153,761 | 86153,876 | 1.107 | 86154,868 | 86154,983 | P. M. November 10th, 1825, Royal Observatory. Clock losing at a mean rate 1°.87 per diem. | Temp. | Time of Disappearance | Time of Re-appearance | Mean of Disappearance and Re-appearance | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 24 h. | Correct for Arc. | Vibra. corr. for Arc. | |-------|----------------------|----------------------|----------------------------------------|-----------------|----------|-------------------------------|-----------------------------|------------------|---------------------| | | h. m. s. | m. s. | | | | Disap. & Re-ap. | Disappearance. | Mean of Disap. and Re-app. | Mean of Disap. and Re-app. | | 45.2 | 6 31 10 | 31 16 | 31 13 | 1.16 | 1.120 | 703 | 703½ | 2.051 | | | 45.2 | 42 53 | 43 00 | 42 56½ | 1.08 | 1.050 | 705 | 705½ | 1.803 | | | 45.2 | 54 38 | 54 45 | 54 41½ | 1.02 | 0.980 | 705 | 706 | 1.572 | | | 45.2 | 7 6 23 | 6 32 | 6 27½ | 0.94 | 0.910 | 706 | 706 | 1.353 | | | 45.2 | 18 9 | 18 18 | 18 13½ | 0.88 | 0.850 | 706 | 706 | 1.181 | | | 45.2 | 29 55 | 30 4 | 29 59½ | 0.82 | 0.780 | 705 | 707 | 0.996 | | | 45.2 | 41 40 | 41 53 | 41 46½ | 0.74 | 0.710 | 706 | 706 | 0.823 | | | 45.2 | 53 26 | 53 39 | 53 32½ | 0.68 | 0.655 | 707 | 707 | 0.702 | | | 45.2 | 8 5 13 | 5 26 | 5 19½ | 0.63 | 0.605 | 706 | 707 | 0.598 | | | 45.2 | 16 59 | 7 14 | 17 6½ | 0.58 | | | | | | Means. | 705,444 | 705,944 | 86153,183 | 86153,357 | 1.231 | 86154,414 | 86154,588 | ### Observations of Coincidences at Greenwich—continued. Height above the level of the sea 181.5 feet. **A.M. November 11th, 1825, Royal Observatory.** Clock losing at a mean rate 1°.87 per diem. Bar. { Begs. 29.273 mer. 42° } = 29.280 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 94 h. | Correct. for Arc. | Vibra. corr. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|---------------------| | | h. m. s. | m. s. | m. s. | ° | s. | Disap. & Re-ap. | Disappearance. | Mean of Disap. [and Re-ap.] | vib. | | 42.0 | 3 14 45 | 14 48 | 14 46.5 | 1.14 | 1.095 | 706 | 707.5 | ..... | 1.961 | | 42.0 | 26 31 | 26 37 | 26 34 | 1.05 | 1.010 | 708 | 708 | ..... | 1.668 | | 42.1 | 38 19 | 38 25 | 38 22 | 0.97 | 0.935 | 708 | 708.5 | ..... | 1.431 | | 42.4 | 50.7 | 50 14 | 50 10.5 | 0.90 | 0.870 | 709 | 709.5 | ..... | 1.237 | | 42.7 | 4 1 56 | 2 4 | 2 00 | 0.84 | 0.810 | 708 | 708.5 | ..... | 1.072 | | 42.9 | 14 44 | 14 53 | 14 48.5 | 0.78 | 0.750 | 711 | 710.5 | ..... | 0.919 | | 42.9 | 25 35 | 25 43 | 25 39 | 0.72 | 0.700 | 708 | 709.5 | ..... | 0.801 | | 42.9 | 37 23 | 37 34 | 37 28.5 | 0.68 | 0.655 | 710 | 710.5 | ..... | 0.701 | | 43.0 | 49 13 | 49 25 | 49 19 | 0.63 | 0.605 | 710 | 709.5 | ..... | 0.598 | | 43.0 | 5 1 3 | 1 14 | 1 8.5 | 0.58 | | | | | | Means. | | | | | | 708,667 | 709,111 | 86154,297 | 86154,450 | 1.154 | 86155,451 | 86155,604 | **P.M. November 11th, 1825, Royal Observatory.** Clock losing at a mean rate 1°.87 per diem. Bar. { Begs. 29.302 mer. 43° } = 29.312 mean cor. to temp. of pend. | Temp. | Time of Disappearance. | Time of Re-appearance. | Mean of Disappearance and Re-appearance. | Arc of vibration. | Mean Arc. | Interval in seconds of Clock. | Observed vibrations in 94 h. | Correct. for Arc. | Vibra. corr. for Arc. | |-------|------------------------|------------------------|------------------------------------------|------------------|-----------|-------------------------------|-----------------------------|-----------------|---------------------| | 44.5 | 5 37 54 | 37 57 | 37 55.5 | 1.15 | 1.110 | 705 | 706.5 | ..... | 2.014 | | 44.2 | 49 39 | 49 45 | 49 42 | 1.07 | 1.030 | 705 | 705.5 | ..... | 1.733 | | 44.2 | 6 1 24 | 1 31 | 1 27.5 | 0.99 | 0.955 | 707 | 707.5 | ..... | 1.491 | | 44.4 | 13 11 | 13 19 | 13 15 | 0.92 | 0.880 | 705 | 707 | ..... | 1.266 | | 44.4 | 24 56 | 25 8 | 25 2 | 0.84 | 0.810 | 709 | 707.5 | ..... | 1.072 | | 44.3 | 36 45 | 36 54 | 36 49.5 | 0.78 | 0.750 | 708 | 708 | ..... | 0.919 | | 44.2 | 48 33 | 48 42 | 48 37.5 | 0.72 | 0.700 | 708 | 709 | ..... | 0.801 | | 44.3 | 7 00 21 | 00 32 | 00 26.5 | 0.68 | 0.655 | 708 | 708 | ..... | 0.701 | | 44.3 | 12 9 | 12 20 | 12 14.5 | 0.63 | 0.605 | 708 | 709 | ..... | 0.598 | | 44.4 | 23 57 | 24 10 | 24 3.5 | 0.58 | | | | | | Means. | | | | | | 707.0 | 707.556 | 86153,722 | 86153,914 | 1.177 | 86154,899 | 86155,091 | Vibrations of the Pendulum at the Royal Observatory at Greenwich, November 1825. The Clock making 86398.13 vibrations in a mean solar day at a mean rate. | Date | Barom. | Ther. | Diff. Temp. & 50 | Vibra. in 24 h. cor. for Arc by Disappearance. | Vibra. of pend. in 24 h. at temp. of 50° by Disappearance. | |------------|--------|-------|------------------|-----------------------------------------------|----------------------------------------------------------| | Nov. 7th | | | | | | | A.M. | 29.115 | 44.11 | 5.89 | 86156.386 | | | P.M. | 29.126 | 46.13 | 3.87 | 86155.521 | | | 8 A.M. | 29.200 | 41.10 | 8.90 | 86157.150 | | | P.M. | 29.058 | 44.12 | 5.88 | 86155.792 | | | 9 A.M. | 28.973 | 45.69 | 4.31 | 86154.692 | | | P.M. | 29.023 | 47.51 | 2.49 | 86154.159 | | | 10 A.M. | 28.613 | 44.25 | 7.75 | 86154.868 | | | P.M. | 28.597 | 45.20 | 4.80 | 86154.414 | | | 11 A.M. | 29.280 | 42.59 | 7.41 | 86155.451 | | | P.M. | 29.312 | 44.32 | 5.68 | 86154.899 | | | Mean. | 29.297 | 44.50 | | | | Results. | From | To | Correct number of vibrations of pend. in a mean solar day. | |------------|----------|-----------------------------------------------------------| | | | Disappearances. | | Nov. 7th A.M. | Nov. 8th P.M. | 86152.867 | | | | 86153.017 | | | | 86152.978 | | | | 86153.008 | | | | 86153.126 | | | | 86153.024 | | | | 86153.037 | | | | 86152.949 | | | | 86153.001 | | | | 86152.958 | | Mean.......| | 86152.996 | | Correction for buoyancy...........| | + 6.041 | | elevation ............| | + 0.450 | | Final No. of vibra. in vacuo at the level of the sea, temp. 50° (Fah.) | 86159.487 | 86159.621 | By this experiment, it appears that the final number of vibrations which would have been made by the pendulum at Greenwich in 24 mean solar hours at the level of the sea, in vacuo, and at the temperature of 50° of Fahrenheit, by the method of disappearance of the white disk is - 86159,487 and by the mean of its disappearance and re-appearance. 86159,621 But from the final results deduced from the experiment made at Greenwich in April 1824, previous to leaving England, the total number of vibrations which would have been made by the same pendulum under the above circumstances, by the method of disappearance, was - - - 86159,250 and by the mean of disappearance and re-appearance. - 86159,380 Having already stated, what I have considered to be the cause of the difference in the number of vibrations of the pendulum in these experiments; the following arithmetical means of the results of the series in April 1824, and November 1825, are to be considered as the proper number of vibrations of the pendulum, at Greenwich, to be compared with those obtained at Port Bowen, and are by the method of disappearance of the white disk - 86159,368 and by the mean of its disappearance and re-appearance. 86159,500.