On the Errors in Longitude as Determined by Chronometers at Sea, Arising from the Action of the Iron in the Ships upon the Chronometers

XV. On the Errors in Longitude as determined by Chronometers at Sea, arising from the action of the iron in the ships upon the Chronometers. By George Fisher, Esq. Communicated by John Barrow, Esq. F. R. S. Read June 8, 1820. The determination of the longitude at sea by timekeepers, is so exceedingly easy from the simplicity of the observations and calculations employed, and from the general practicability of the method, as to render chronometers, in the present improved state of navigation, almost indispensable articles in the equipment of ships for foreign service; and I shall feel happy if the following observations may, in any way, contribute to the more accurate determination of the longitude by this method. The sudden alteration in the rates of chronometers when taken on board of ships, has been frequently observed by intelligent seamen; and is generally ascribed to the motion of the vessels. Before, however, I attempt to account for this alteration, I shall first prove that it actually takes place; and, in order to do this, shall relate the circumstances connected with the chronometers on board the Dorothea and Trent, commanded by Captain Buchan, which occurred during the late voyage to the North Pole. Soon after the arrival of the ships on the coast of Spitzbergen, the chronometers on board the Dorothea (five in number) were found to be rapidly gaining on their former rates as determined in London previous to the ship's sailing; in consequence of which the land appeared considerably to the westward of its true position as determined by lunar observation, and they were found to be still gaining daily, which appeared not only from each subsequent set of lunars, but also by comparing the longitude of different points of land determined by the chronometers, with the longitude of the same points ascertained in the same way some time afterwards. For instance; the longitude of a remarkable point of land on the north-west coast of Spitzbergen, called Cloven Cliff, was found by a mean of the observations taken with the chronometers on June 21, 1818, to be $10^\circ 35' 27''$ E; but the longitude of the same point of land on July 31, was $10^\circ 15' 37''$ E, making a difference of no less than about $20'$ of longitude in five weeks; that is, estimating the longitude with the same rates and errors as determined in London before their departure; from this, therefore, it appears, they had been gaining on their former rates, or had been increasing their gaining rates, and diminishing their losing ones. An opportunity soon afterwards occurred of observing the effect produced upon the chronometers by removing them on shore. On the 9th of August, the chronometers, nine in number, were landed on an island, where a temporary observatory had been erected for the purpose, and the latitude of which had been accurately determined with a repeating circle made by Troughton, when it was found that the acceleration immediately ceased; for the longitude of the place by chronometers, August 12, was $9^\circ 42' 36''$ E, but on the 27th, it was $10^\circ 1' 0''$ E, making a difference of $18' 24''$ of longitude in fifteen days, using the former rates. Since, therefore, the chronometers were getting easterly by their removal on shore, the acceleration must have ceased; which will appear upon consideration. A similar circumstance was observed by Lieut. Franklin to take place with the chronometers on board the Trent, which were four in number; and he observes, "It may be worthy of remark, that the chronometers taken out by the Hon. Captain Phipps, showed too great westerly longitude, and consequently gained on these seas. The fact of so many chronometers altering their rates the same way, is curious, but I am not aware that any cause can be assigned." The effect produced upon one or two of the chronometers by their removal to land, was very remarkable; a chronometer made by Baird was (by observations taken on shore near where the ships lay at anchor, by Lieutenants Franklin and Beechey, with false horizon, and eight inch reflecting circles of Troughton, from August 8, A.M. to 12, P.M.) losing $3,"4$ daily when on board; but upon its removal on shore to the observatory, its rate per transit, from August 16, to 26, was observed by myself to be $18,"2$ losing. Upon again removing it on board, it was found by observation, as before, to be losing $6,"5$ daily; from which it appears the chronometer lost no less than about thirteen or fourteen seconds daily by its removal on shore. Another chronometer in the Trent, made by Pennington, had been gaining rapidly on board; when taken on shore, it acquired immediately a losing rate of $1,"8$, nearly the same as it had in London before the vessels sailed. A chronometer of my own, by Arnold, was affected likewise nearly as much, losing about $9"$ daily by its removal on shore. In the other chronometers the alteration was less sudden, but was ultimately not less considerable; and they were several days on shore before they acquired a steady rate, as will appear by the following table of their rates, during the interval of the respective dates. **Table of Rates of Chronometers immediately when landed, August 9th, 1818.** | No. | Earnshaw | Arnold | Barraud | Arnold | Clock | |-----|----------|--------|---------|--------|-------| | | | | | | | | Aug 9 | +12.0 | -0.2 | +8.1 | -33.5 | | | 11 | +10.2 | 0 | +7.9 | -34.2 | | | 12 | +7.98 | -1.85 | +0.8 | -36.2 | +70.60| | 16 | +6.2 | -5.1 | +7.1 | -40.9 | +69.03| | 20 | +5.63 | -5.2 | +2.8 | -37.7 | +69.12| | 23 | +4.02 | -6.14 | +4.3 | -41.5 | +69.29| The rates from August 12 to 26, were determined by the sun’s transit, and those from August 9th (the day on which the chronometers were landed) to the 12th, by a comparison with the clock, supposing its mean rate +69,"5, as no observation occurred during this interval; and by this table it appears, that the chronometers when landed were rapidly diminishing their gaining rates, and increasing their losing ones. In the others the effect was almost immediate. The clock and chronometers were likewise landed upon a small island in Fair Haven, on the north coast of Spitzbergen, on the 30th June; and, as the same circumstances occurred, it will be needless to detail them. The following table is intended to show the difference between the rates on board the ships and what they would have been had they been on shore. | Chronometers | Error, Greenwich time. | Difference. | Interval. | Mean Rates at Sea. | Mean Rates on Shore. | |--------------|------------------------|-------------|-----------|--------------------|---------------------| | No. 1. Earnshaw. | April 11, + 7.40.1 | +18.52.1 | days. 136 | + 8.0 | + 3.8 | | | Aug. 25, + 26.32.2 | | | | | | 2. Arnold. | April 11, -0.42 | -3.33 | 136 | -1.5 | -5.2 | | | Aug. 25, -4.15 | | | | | | 3. Arnold. | May 7, -1.44 | 1.52 | 56 | -2.0 | -6.5 | | | July 2, -3.36 | | | | | | 4. Barraud. | April 1, -6.1 | +5.56.5 | 146 | +2.5 | +1.2 | | | Aug. 25, +5.55.5 | | | | | | 5. Arnold. | April 15, -6.38 | -28.10 | 132 | -12.8 | -22.4 | | | Aug. 25, -28.48 | | | | | | 6. Earnshaw. | April 11, +1.13 | -1.10.8 | 136 | -0.5 | -0.93 | | | Aug. 25, +0.2.2 | | | | | | 7. Pennington.| April 11, +0.53 | +13.35 | 136 | +5.8 | -0.63 | | | Aug. 25, +13.57 | | | | | | 8. Arnold. | April 13, -6.24 | +16.17.5 | 134 | +7.3 | -2.5 | | | Aug. 25, -15.53.5 | | | | | | 9. Baird. | April 15, +6.25.1 | +4.47.4 | 132 | +2.2 | -5.15 | | | Aug. 25, +5.12.5 | | | | | The errors of the chronometers in April, were those obtained in London before the ships sailed; those on the 25th August were determined at the Observatory on Dane's Island, Spitzbergen, the longitude of which was determined by a great many observations of the distances of the sun and moon for several days with Troughton's eight inch sextants and reflecting circles. The rates in the column entitled "Mean Rates at Sea," are deduced by dividing the difference of the errors by the interval. The rates in the column entitled "Mean Rates on Shore," or more properly what they would have had, are means between the rates of chronometers on shore before leaving England, and those obtained at Spitzbergen; and although a mean between the rates of chronometers obtained at different times, may not accurately be the mean rate they would have had during the interval of those times, from the continued variation to which they are subject; yet, upon comparing the two last columns together, of the rates thus deduced, it will be perceived, that in all the chronometers their gaining rates had either been increased, or their losing ones diminished on ship-board, or in other words, they had all been accelerated. Nor is this acceleration peculiar to high latitudes; it was observed very soon after the chronometers were put on board in the River, particularly in Nos. 3 and 8, which, upon arriving at Shetland, were found to have gained instead of losing rates, which they had in London. This acceleration was very soon perceptible in the chronometers taken out by the Hon. Captain Phipps, made by KENDAL and ARNOLD. Mr. LYONS, who accompanied him, landed at Sheerness Fort, and found the longitude by them to be $30^\circ 0''$ E, which is about $13' W$ of the true longitude, as determined in the Trigonometrical Survey. The same occurrence took place last summer (1819). The longitude of a place in one of the Orkney Islands, as determined by three chronometers made by ARNOLD, two of them belonging to myself, the other to Lieut. E. HOME, R. N. who accompanied me, was $6' 40'' W$. of the longitude determined by the difference of AR of stars E and W of $\Omega$. Again, in the trial of Mr. HARRISON's timekeeper, in 1764, the longitude of Barbadoes by the watch was $10' 45''$ more to the westward than that determined by astronomical observations made by the persons sent out for that purpose. Soon after this trial, the commissioners of longitude agreed with Mr. KENDAL, one of the watchmakers appointed by them to receive Mr. HARRISON's discoveries, to make another watch on the same construction, which went considerably better than Mr. HARRISON's. Mr. KENDAL's watch was sent out with Captain Cook in his second voyage towards the South Pole and round the world, in the years 1772-3-4 and 5, "when the only fault found in the watch was, that its rate of going was continually accelerated." It now remains, therefore, to determine what this acceleration arises from. That it does not arise from the motion of the vessels, is evident in the case of the nine chronometers on board the Dorothea and Trent; since the acceleration was observed when the ships were firmly beset with ice; also in the case of the alteration in the rates of the chronometers upon landing, and taking them on board again at Dane's Island, the ships were riding at anchor close in shore without any perceptible motion. An account was also kept on board and on shore, of the state of the temperature and barometer, every two hours, both night and day; and upon comparing them together, there does not appear to be the least correspondence between the change of rates and the temperature at the time. It appears therefore to me, that this acceleration arose entirely from the magnetic action exerted by the iron in the ship on the inner rim of the balance, which is made of steel. That the iron in the ships becomes magnetic, is plain, from the polarity which exists in it; the whole forming altogether one large magnet, having its south pole on deck nearly amidships, and its north pole below. This is seen from the constant deviation of the north end of the compasses placed on deck towards the centre of the ship, as appears from recent observations, which I have mentioned elsewhere. Nor is it surprising that the force exerted by the ship's iron (thus become magnetical) on the balance of the chronometers, should be sufficient to cause a very sensible alteration in the rate of going, when we consider how easily, in other cases, the presence of any thing magnetical is detected by the alteration of the rate of a chronometer; and when we consider the great influence exerted by this iron upon the binnacle compasses at very considerable distances, and in situations where the utmost precaution is used to remove every piece of iron from them, by using copper-bolts, fastenings, &c. It remains only to determine, how far this alteration in the rates of the chronometers, can be reconciled with that observed in chronometers when under the influence of magnets placed in different positions with respect to their balances. To determine this, two watches were used, with steel balances and horizontal escapements, one by Earnshaw, the other by Allan and Caithness; also two chronometers made by Arnold. To each of these watches were applied, at a distance of two inches from the balance, magnets of twelve inches in length, in four different positions, and in the planes of the balances. The following Table will show the rates of the watches in twenty-four hours, deduced by comparing them with an excellent clock with Graham's dead beat escapement, and regulated by transit. | No. 1. | No. 2. | No. 3. | No. 4. | |-------|-------|-------|-------| | N | +9.15 | +5.0 | +0.34 | +0.41 | | S | +8.12 | +21.0 | +2.18 | +0.44 | | N | +8.0 | +18.0 | +1.28 | -1.43 | | S | +48.0 | +8.0 | +5.27 | -0.36 | | N | +47.10| +17.8 | +5.22 | +1.3 | | S | +72.0 | +8.44 | -0.14 | +0.41 | | N | +4.14 | +4.32 | +2.47 | +1.12 | | S | -2.0 | +15.0 | -1.2 | +1.24 | The first column in this table shows the pole of the magnet applied to the watch; the second and third, the rate or effect produced on each watch; the fourth column shows the figure on the face of the watch opposite to which the magnet was applied. The watch, No. 1, gained with both poles, and in every position of the magnet but one. No. 2, gained with both poles in every position. Nos. 3 and 4 gained in every position but two; and the quantities lost in the positions were far exceeded by the accelerations caused by the opposite poles, excepting one case in that of No. 4. The magnets were likewise placed in different positions out of the planes of the balances; the results were very similar to those above, but differing in quantity, according to the distance of the magnets from the planes of the balances. Upon placing the magnets very near to the rim of the balances, a very rapid acceleration took place with both poles, and in every position of the magnets, particularly in the watches Nos. 1 and 2. Upon too near an approach of the magnets, the watch No. 1, and chronometer No. 3, were rendered useless; the former, when the magnets were taken away, gaining no less than about $1\frac{1}{4}$ hour, and the chronometer losing about $50''$ in 24 hours; and in again repeating the experiments in the plane of the balances, the rates of the chronometers (without the magnets) were so variable, that it was necessary to determine their rates before and after each application of the magnets; the following, however, is a Table of the results upon the chronometers Nos. 3 and 4. | No. 3 | No. 4 | |-------|-------| | NS | +0.27 | +0.435 | | S | +1.24 | +0.46 | | | | 3 | | NS | -5.32 | -1.40 | | S | +6.15 | -1.37 | | | | 6 | | NS | +5.19 | +1.18 | | S | -1.53 | +1.12 | | | | 9 | | NS | +1.59 | +1.117 | | S | +2.73 | +1.29 | | | | 12 | | NS | +0.31 | +1.14 | | S | +2.8 | +0.43 | | | | 3 | | NS | -5.9 | -1.24 | | S | +4.257| -0.59 | | | | 6 | | NS | +5.25 | +0.55 | | S | -1.53 | +0.42 | | | | 9 | | NS | +2.33 | +1.5 | | S | -2.23 | +1.6 | | | | 12 | Each of these results in this Table, is the difference of the rates when the magnets were applied, and a mean of the rates of the chronometers before and after the application of the magnets. The rate of the chronometer No. 3, is very different from that given in the former Table; that of No. 4, is nearly the same, and does not appear to have been affected, as No. 3 was, by the close approach of the magnet. Upon the whole, however, it appears that chronometers will be generally accelerated (particularly if their balances have not received polarity by the too near approach of anything magnetical) on ship-board. It appears probable, likewise, that the force of the balance springs is affected in the same way; since it is well known that chronometers having gold balance springs, although more difficult to adjust, yet keep better rates at sea than the others. However this may be, these observations show the necessity of not trusting to the rates of chronometers ascertained during the time they are on shore; and if the rates are ascertained on board, the chronometers should always be kept in the same place, and also in the same position with respect to the ship; for I have but little doubt that, upon an accurate trial, a chronometer will be found to change its rate, more or less, according as these circumstances are attended to. If these precautions are not taken, land will appear to be considerably to the westward of its true position; this is particularly exemplified in the observations of the Hon. Captain Phipps; from which, nearly the whole line of coast on the west side of East Greenland has been placed nearly $1\frac{1}{2}°$ too much to the westward, by reason of the acceleration of his chronometers; the same circumstance would have occurred with the chronometers in both of the ships Dorothea and Trent, in the late voyage, had not the longitude been otherwise determined. It is therefore highly requisite that attention should be paid to a circumstance so much connected with the improvement of geography as well as the safety of the seaman. As an Appendix to these observations, I beg leave to add the following Table of Rates, furnished by Mr. Coleman, to which I have prefixed his letter as an introduction. 157, Leadenhall-Street, 5th June, 1820. Sir, In compliance with the wish of our common friend Lieutenant Everard Home, I have much pleasure in sending you a table of rates of chronometers. My profession as Teacher of Navigation, conjointly with Mr. Norie, which connects me so intimately with the Officers of the Honourable East India Company, employed on board the ships trading to India, has enabled me to present you with this table upon an enlarged scale. While engaged in the same service eighteen years, this subject occupied my attention, and it affords me much satisfaction that you are bringing the subject before the Royal Society. My remarks correspond very much with those, I understand, you are now bringing forward. I am, Sir, Your obedient servant, George Coleman. | Date | Persons' Names | Ships' Names | Burthen in Tons | Copper or Iron fastened | Chronometers | No. of Days to wind up | Rates given | Rates | |------------|-------------------------|----------------------|-----------------|-------------------------|--------------|------------------------|-------------|-------| | 1802 & 1803 | Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | 3.4 gaining | 5.0 gaining | | | | | | | Margetts | 8 | 5.0 gaining | 5.2 gaining | | | | | | | Margetts | 8 | 2.5 losing | 2.0 losing | | | | | | | Earnshaw | 1 | 6.2 losing | 7.5 losing | | 1804 & 1805 | Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | 4.5 gaining | 6.0 gaining | | | | | | | Margetts | 8 | 5.0 gaining | 5.2 gaining | | | | | | | Earnshaw | 1 | 6.4 losing | 8.0 losing | | 1806 & 1807 | Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | 2.5 gaining | 3.8 gaining | | | | | | | Arnold | 1 | 4.6 losing | 4.0 losing | | | | | | | Margetts | 8 | 5.0 gaining | 5.3 gaining | | | | | | | Earnshaw | 1 | 1.4 losing | 1.5 gaining | | 1808 & 1809 | Capt. Dodds | H. C. S. Walmer Castle | 1260 | Iron | Barraud | 1 | 7.3 gaining | 6.0 gaining | | | | | | | Brockbank | 8 | 4.0 losing | 2.8 losing | | | | | | | Arnold | 1 | 3.6 gaining | 4.0 gaining | | 1810 & 1811 | Capt. Mayne | H. C. S. Batavia | 750 | Iron | Earnshaw | 1 | 6.7 losing | 3.2 losing | | | Mr. Coleman | | | | Arnold | 1 | 3.7 gaining | 5.4 gaining | | | | | | | Brockbank | 2 | 11.8 losing | 13.8 losing | | | | | | | | | These Chronometers were on shore at Calcutta upwards of three months | | 1812 | Capt. Mayne | H. C. S. Batavia | 750 | Iron | Earnshaw | 1 | 10.5 gaining | 18.0 gaining | | | Mr. Coleman | | | | Arnold | 1 | 6.7 gaining | 2.4 gaining | | | | | | | Brockbank | 2 | 15.4 losing | 18.6 losing | | 1813 & 1814 | Capt. Blanchard | H. C. S. James Sibbald | 700 | Iron | | | The Book containing the various changes of these Chronometers | | | Capt. Money | | | | | | N. B. The above Chronometers were all under my entire | | | Mr. Coleman | | | | | | control | | Rates given. | Rates found. | Difference of Rates. | REMARKS. | |--------------|--------------|----------------------|----------| | 4 gaining | 5.0 gaining | 1.6 gained | These Chronometers went remarkably steady during the voyage, with the rates found. | | 0 gaining | 5.2 gaining | 0.2 gained | | | 5 losing | 2.0 losing | 0.5 gained | | | 2 losing | 7.5 losing | 1.3 lost | | | 5 gaining | 6.0 gaining | 1.5 gained | These Chronometers gained on board the same as on the preceding voyage. This also lost in similar proportion. | | 0 gaining | 5.2 gaining | 0.2 gained | | | 4 losing | 8.0 losing | 1.6 lost | | | 5 gaining | 3.8 gaining | 1.3 gained | The same Chronometer as above, same alteration. | | 6 losing | 4.0 losing | 0.6 gained | | | 0 gaining | 5.3 gaining | 0.3 gained | | | 4 losing | 1.5 gaining | 2.9 gained | | | 3 gaining | 6.0 gaining | 1.3 lost | | | 0 losing | 2.8 losing | 1.2 gained | | | 6 gaining | 4.0 gaining | 0.4 gained | | | 7 losing | 3.2 losing | 3.5 gained | This Chronometer went very irregular during the voyage. | | 7 gaining | 5.4 gaining | 1.7 gained | | | 3 losing | 13.8 losing | 2.0 lost | | Calcutta upwards of three months, and then had the following rates given and found. | Rates given. | Rates found. | Difference of Rates. | REMARKS. | |--------------|--------------|----------------------|----------| | 5 gaining | 18.0 and 23" gaining | ............ | No reliance on this Chronometer at any time. | | 7 gaining | 2.4 gaining | 1.7 gained | | | 4 losing | 18.6 losing | 3.2 lost | This Chronometer gradually lost during the whole voyage. | Various changes of these Chronometers is in Captain Blanchard's possession, whose arrival in England is daily expected. These Chronometers were all under my entire charge; I therefore can vouch for the accuracy of the above statements.—G. Coleman. | Date | Persons' Names | Ships' Names | Burthen in Tons | Copper or Iron fastened | Chronometers | No. of Days to wind up | Rates given | Rates for | |------------|----------------|-----------------------|-----------------|-------------------------|--------------|------------------------|-------------|----------| | 1819 & 1820 | Capt. Tennent | H. C. S. Apollo | 700 | Iron | Barraud | 1 | 3.0 losing | 2.5 losing | | | | | | | Brockbank & Co. | 8 | 3.5 gaining | 4.2 gaining | | | | | | | | 2 | 9.5 gaining | 12.5 and 16 | | 1818 & 1819 | Capt. S. Lee | H. C. S. Moffatt | 720 | Iron | Brockbank | 1 | 4.5 losing | 3.2 losing | | | | | | | Barraud | 2 | 2.4 gaining | 3.6 gaining | | 1819 & 1820 | Capt. Stewart. | F. T. Sappho | 360 | Copper | Barraud | 8 | 6.8 losing | 5.0 losing | | | | | | | Hatton | 8 | 2.4 gaining | 7.0 gaining | | | | | | | Parkinson & Co. | 1 | 10.0 gaining | 16.5 and 21 | | 1819 | Capt. Pitcher | F. T. Bloxbornbury | 720 | Copper | Morris | 1 | 2.2 gaining | 3.5 gaining | | 1818 & 1819 | Capt. Foord | S. S. Phoenix | 460 | Iron | Brockbank & Co. | 2 | 3.5 losing | 6.3 losing | | 1815 & 1816 | Capt. Forbes | H. C. S. James Sibbald | 700 | Iron | Hatton | 8 | 14.0 gaining | 14.0 gaining | | | | | | | Barraud | 1 p. | Going at mean time | 0.3 gaining | | | | | | | Earnshaw | 1 | 15.0 losing | 18.5 losing | | | | | | | | | 14.5 gaining | 16.0 gaining | | | | | | | | | 19.2 losing | 20.7 losing | | 1818 & 1819 | Capt. Forbes | H. C. S. James Sibbald | 700 | Iron | Hatton & Harris | 8 | 9.5 losing | 8.5 losing | | | | | | | Hatton & Harris | 1 p. | 3.0 gaining | 5.0 gaining | | | | | | | Barraud | 1 p. | 4.5 losing | 6.0 losing | | | | | | | | | 9.0 losing | 9.0 losing | | | | | | | | | 5.0 gaining | 5.0 gaining | | | | | | | | | 7.0 losing | 7.0 losing | | 1819 & 1820 | Capt. Doveton | T. F. Lotus | 580 | Copper | Barraud | 8 | 6.8 losing | 8.0 losing | On the Ship's returning home, the above Chronometers had rates as under, after being | Chronometers | No. of Days to wind up | Rates given | Rates for | |--------------|------------------------|-------------|----------| | Hatton | 8 | 14.5 gaining | 16.0 gaining | | Earnshaw | 1 | 19.2 losing | 20.7 losing | On the homeward bound passage, the same Chronometers had the following: | Chronometers | No. of Days to wind up | Rates given | Rates for | |--------------|------------------------|-------------|----------| | Hatton & Harris | 8 | 9.0 losing | 9.0 losing | | Hatton & Harris | 1 p. | 5.0 gaining | 5.0 gaining | | Barraud | 1 p. | 7.0 losing | 7.0 losing | | Rates given. | Rates found. | Difference of Rates. | REMARKS. | |--------------|--------------|----------------------|----------| | 2.5 losing | 0.5 gained | | | | 4.2 gaining | 0.7 gained | | | | 12.5 and 16 gaining | 6.5 gained | | Barraud's Chronometers went steady several months before they altered their rates; but Brockbank's altered its rate in a few weeks. | | 3.2 losing | 1.3 gained | | These Chronometers went steady within 2 or 3 tenths, during a voyage of fourteen months. | | 3.6 gaining | 1.2 gained | | | | 5.0 losing | 1.8 gained | | These went pretty regular with ship rates. | | 7.0 gaining | 4.6 gained | | | | 16.5 and 22 gaining | 12.0 gained | | This Chronometer proved a very bad one. | | 3.5 gaining | 1.3 gained | | | | 6.3 losing | 2.8 lost | | This Chronometer went steady at 6.3 till let down. | | 14.0 gaining | ............ | | No difference was discovered in the going of this Chronometer outward. | | 0.3 gaining | 0.3 gained | | This Chronometer going well at 0.3, was sold at Calcutta. | | 18.5 losing | 3.5 lost | | Altered its rate after leaving Madeira. | | 16.0 gaining | 1.5 gained | | The Chronometers went very steady during the homeward passage with the rates found. | | 20.7 losing | 1.5 lost | | | | 8.5 losing | 0.5 gained | | These Chronometers were rated at Madeira, and afterwards went steady at those rates. | | 5.0 gaining | 2.0 gained | | | | 6.0 losing | 1.5 lost | | | | 9.0 losing | | | It therefore appears the Chronometers did not vary their rates homeward in the most trifling degree. | | 5.0 gaining | | | | | 7.0 losing | | | | | 8.0 losing | 1.2 lost | | This Chronometer did not alter its rate till at Calcutta. | | Date | Persons' Names | Ships' Names | Tonnage | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rates | |------------|----------------|-----------------------|---------|-------------------------|------------------------|------------------------|---------------|-------| | 1802 & 1803| Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | Pocket | 3.4 gain | | | | | | | Margetts | 8 | Box | 5.0 gain | | | | | | | Ditto | 8 | — | 2.5 loss | | | | | | | Earnshaw | 1 | Pocket | 6.2 loss | | 1804 & 1805| Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | Pocket | 4.5 gain | | | | | | | Margetts | 8 | Box | 5.0 gain | | | | | | | Ditto | 1 | Pocket | 6.4 loss | | 1806 & 1807| Capt. Dunsford | H. C. S. Ceres | 1200 | Iron | Arnold | 1 | Pocket | 2.5 gain | | | | | | | Ditto | 1 | — | 4.6 loss | | | | | | | Margetts | 8 | Box | 5.0 gain | | | | | | | Earnshaw | 1 | Pocket | 1.4 loss | | 1808 & 1809| Capt. Dodds | H. C. S. Walmer Castle| 1200 | Iron | Barraud | 1 | Pocket | 7.3 gain | | | | | | | Brockbank | 8 | Box | 4.0 loss | | | | | | | Arnold | 1 | Pocket | 3.6 gain | | 1810 & 1811| Capt Mayne | H. C. S. Batavia | 750 | Iron | Earnshaw | 1 | Box | 6.7 loss | | | Mr. Coleman | | | | Arnold | 1 | Pocket | 3.7 gain | | | | | | | Brockbank | 2 | Box | 11.8 loss | | 1812 | Capt. Mayne | | | | Earnshaw | 1 | Box | 10.5 gain | | | Mr. Coleman | | | | Arnold | 1 | Pocket | 6.7 gain | | | | | | | Brockbank | 2 | Box | 15.4 loss | | 1813 & 1814| Capt. Blanchard| H. C. S. James Sibbald| 700 | Iron | Hatton | 8 | Box | 7.2 gain | | | Capt. Money | | | | Barraud | 2 | — | 2.4 gain | | | Mr. Coleman | | | | Ditto | 1 | Pocket | 3.5 loss | | | Mr. Decharme | | | | Brockbank | 1 | Box | 10.8 loss | | | | | | | Ditto | 1 | — | 4.4 gain | | | | | | | Barraud | 1 | Pocket | 2.6 gain | | 1819 & 1820| Capt. Tennent | H. C. S. Apollo | 700 | Iron | Barraud | 1 | Box | 3.0 loss | | | | | | | Barraud | 8 | — | 3.5 gain | | | | | | | Brockbank | 2 | — | 9.5 gain | | 1818 & 1819| Capt. S. Lee | H. C. S. Moffatt | 720 | Iron | Brockbank | 1 | Box | 4.5 loss | | | | | | | Barraud | 2 | — | 2.4 gain | | 1815 & 1816| Captain Forbes | H. C. S. James Sibbald| 700 | Iron | Hatton | 8 | Box | 14.0 gain | | | | | | | Barraud | 1 | Pocket | On me | | | | | | | Earnshaw | 1 | Box | 15.0 loss | The above Chronometers were on shore at Calcutta upwards. These Chronometers were on shore about eleven weeks. | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rates given | Rates found | Difference of Rates | |-------------------------|------------------------|------------------------|--------------|-------------|-------------|---------------------| | Iron | Arnold | 1 | Pocket | 3.4 gaining | 5.0 gaining | 1.6 gained | | | Margetts | 8 | Box | 5.0 gaining | 5.2 gaining | 0.2 gained | | | Ditto | 8 | — | 2.5 losing | 2.0 losing | 0.5 gained | | | Earnshaw | 1 | Pocket | 6.2 losing | 7.5 losing | 1.3 lost | | Iron | Arnold | 1 | Pocket | 4.5 gaining | 6.0 gaining | 1.5 gained | | | Margetts | 8 | Box | 5.0 gaining | 5.2 gaining | 0.2 gained | | | Earnshaw | 1 | Pocket | 6.4 losing | 8.0 losing | 1.6 lost | | Iron | Arnold | 1 | Pocket | 2.5 gaining | 3.8 gaining | 1.3 gained | | | Ditto | 1 | — | 4.6 losing | 4.0 losing | 0.6 gained | | | Margetts | 8 | Box | 5.0 gaining | 5.3 gaining | 0.3 gained | | | Earnshaw | 1 | Pocket | 1.4 losing | 1.5 gaining | 2.9 gained | | Iron | Barraud | 1 | Pocket | 7.3 gaining | 6.0 gaining | 1.3 lost | | | Brockbank | 8 | Box | 4.0 losing | 2.8 losing | 1.2 gained | | | Arnold | 1 | Pocket | 3.6 gaining | 4.0 gaining | 0.4 gained | | Iron | Earnshaw | 1 | Box | 6.7 losing | 3.2 losing | 3.5 gained | | | Arnold | 1 | Pocket | 3.7 gaining | 5.4 gaining | 1.7 gained | | | Brockbank | 2 | Box | 11.8 losing | 13.8 losing | 2.0 lost | | Iron | Hatton | 8 | Box | 7.2 gaining | 7.2 gaining | No difference | | | Barraud | 2 | — | 2.4 gaining | 3.2 gaining | 0.8 gained | | | Ditto | 1 | Pocket | 3.5 losing | 2.0 losing | 1.5 gained | | | Brockbank | 1 | Box | 10.8 losing | 12.6 losing | 1.8 lost | | | Ditto | 1 | — | 4.4 gaining | 5.8 gaining | 1.4 gained | | | Barraud | 1 | Pocket | 2.6 gaining | 2.6 gaining | No difference | | Iron | Barraud | 1 | Box | 3.0 losing | 2.5 losing | 0.5 gained | | | Barraud | 8 | — | 3.5 gaining | 4.2 gaining | 0.7 gained | | | Brockbank | 2 | — | 9.5 gaining | 12.5 then 16 ditto | 16.5 gained | | Iron | Brockbank | 1 | Box | 4.5 losing | 3.2 losing | 1.3 gained | | | Barraud | 2 | — | 2.4 gaining | 3.6 gaining | 1.2 gained | | Iron | Hatton | 8 | Box | 14.0 gaining | 14.0 gaining | No difference | | | Barraud | 1 | Pocket | On mean time. | 0.3 gaining | 0.3 gained | | | Earnshaw | 1 | Box | 15.0 losing | 18.5 losing | 3.5 lost | These Chronometers were on shore at Calcutta upwards of three months, and then had the following rates given and found. The above Chronometers were on shore about eleven weeks, and then the following rates were both given and found. | Rates found. | Difference of Rates. | REMARKS. | |-------------|----------------------|----------| | 5.0 gaining | 1.6 gained | These Chronometers went remarkably well during the voyage, with the rates found. | | 5.2 gaining | 0.2 gained | | | 2.0 losing | 0.5 gained | | | 7.5 losing | 1.3 lost | | | 6.0 gaining | 1.5 gained | These Chronometers gained during this voyage in the same proportion as in the preceding one. | | 5.2 gaining | 0.2 gained | This Chronometer lost in similar proportion. | | 8.0 losing | 1.6 lost | | | 3.8 gaining | 1.3 gained | In the two former voyages there was nearly the same alteration. | | 4.0 losing | 0.6 gained | This Chronometer a very excellent one. | | 5.3 gaining | 0.3 gained | This Chronometer went five years & a half at 5' on shore, and 5'.3 on board. | | 1.5 gaining | 2.9 gained | Same Chronometer as mentioned on a former voyage. | | 6.0 gaining | 1.3 lost | These Chronometers went very steady with the rates given them. | | 2.8 losing | 1.2 gained | | | 4.0 gaining | 0.4 gained | | | 3.2 losing | 3.5 gained | This Chronometer went irregular during the whole voyage. | | 5.4 gaining | 1.7 gained | | | 13.8 losing | 2.0 lost | | | 18.0 and 23 gaining | ........... | No reliance on this Chronometer at any time. | | 8.4 gaining | 1.7 gained | This Chronometer gradually lost during the whole voyage. | | 18.6 losing | 3.2 lost | | | 7.2 gaining | No difference | These Chronometers went remarkably well with the ship, except Capt. Money's box one, which at times veered and hauled exceedingly. | | 3.2 gaining | 0.8 gained | | | 2.0 losing | 1.5 gained | | | 12.6 losing | 1.8 lost | | | 5.8 gaining | 1.4 gained | | | 2.6 gaining | No difference | | | 2.5 losing | 0.5 gained | These Chronometers went extremely well during the whole voyage. | | 4.2 gaining | 0.7 gained | This was a very indifferent one throughout. | | 12.5 then 16 ditto | 16.5 gained | | | 3.2 losing | 1.3 gained | These scarcely varied from the rates found during the whole voyage. | | 3.6 gaining | 1.2 gained | | | 14.0 gaining | No difference | Chronometer was sold at Calcutta. | | 0.3 gaining | 0.3 gained | | | 18.5 losing | 3.5 lost | | | 16.0 gaining | 1.5 gained | These went very steady on the passage home with the rates found. | | 20.7 losing | 1.5 lost | | | Date | Persons’ Names | Ships’ Names | Tonnage | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rates | |------------|-------------------------|-------------------------------|---------|------------------------|------------------------|------------------------|---------------|-------| | 1818 & 1819 | Capt. Forbes | H. C. S. James Sibbald | 700 | Iron | Hatton | 8 | Box | 9.5 loss | | | | | | | Ditto | 1 | Pocket | 3.0 gain | | | | | | | Barraud | 1 | | 4.5 loss | | | | | | | | | | | | | | | | | Hatton | 8 | Box | 9.0 loss | | | | | | | Ditto | 1 | Pocket | 5.0 gain | | | | | | | Barraud | 1 | | 7.0 loss | | 1819 & 1820 | Capt Stewart | Ship Sappho | 360 | Copper | Barraud | 8 | Box | 6.8 loss | | | | | | | Hatton | 8 | | 2.4 gain | | | | | | | Parkinson | 1 | | 10.0 gain | | 1818 & 1819 | Capt. Pitcher | H. C. S. Bloxbornbury | 720 | Copper | Morris | 1 | Pocket | 2.2 gain | | 1818 & 1819 | Capt. Foord | S. S. Phœnix | 460 | Copper | Brockbank | 2 | Box | 3.5 loss | | 1819 & 1820 | Capt. Doveton | Lotus | 580 | Copper | Barraud | 8 | Box | 6.8 loss | | 1818 & 1819 | Capt. W. Morgan | Layton | 400 | Iron | Barraud | 2 | Box | 6.0 loss | | | | | | | Ditto - Homeward bound | | | 7.0 loss | | 1819 & 1820 | Capt. Ogelvie | Juliana | 448 | Iron | Barraud | 1 | Box | 6.0 loss | | | | | | | Ditto - Homeward bound | | | 6.0 loss | | 1819 & 1820 | Capt. Scott | H. C. S. Charles Grant | 1200 | Copper | Barraud | 8 | Box | 6.1 loss | | 1814 & 1815 | Capt. Hope | H. C. S. Surat Castle | 1200 | Iron | Barraud | 8 | Box | 1.8 gain | | 1816 & 1817 | Capt. Hope | H. C. S. Surat Castle | 1200 | Iron | Same Chronom. | 8 | Box | 5.2 gain | | 1813 & 1814 | Capt. Franklin | H. C. S. Northumberland | 640 | Iron | Barraud | 8 | Box | 0.4 loss | | 1814 & 1815 | Capt. Cameron | H. C. S. Ann | 610 | Iron | Barraud | 8 | Box | 2.0 gain | | 1816 & 1817 | Capt. B. Laing | H. C. S. Royal Charlotte | 1200 | Iron | Barraud | 8 | Box | 0.0 | | 1818 | Capt. M’Kellar, R. N. | H. M. S. Pique | | | Barraud | 8 | Box | 6.5 loss | | | | | | | | | | | | | | | | | Next six months on ship its rate was | 6.5 loss | | 1818 & 1819 | Capt. Taylor | Cæsar | 510 | Copper | Barraud | 8 | Box | 2.7 loss | | | | | | | | | | | | | | | | | Next twelve months on shore, its rate was | 0.0 | | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rates given | Rates found | Difference of Rates | |------------------------|------------------------|------------------------|--------------|-------------|-------------|---------------------| | Iron | Hatton | 8 | Box | 9.5 losing | 8.5 losing | 0.5 gained | | Ditto | | 1 | Pocket | 3.0 gaining | 5.0 gaining | 2.0 gained | | Barraud | | 1 | | 4.5 losing | 6.0 losing | 1.5 lost | | Copper | Barraud | 8 | Box | 6.8 losing | 5.0 losing | 1.8 gained | | | Hatton | 8 | | 2.4 gaining | 7.0 gaining | 4.6 gained | | | Parkinson | 1 | | 10.0 gaining| 16.5 then 22 gaining | 12.0 gained | | Copper | Morris | 1 | Pocket | 2.2 gaining | 3.5 gaining | 1.3 gained | | Copper | Brockbank | 2 | Box | 3.5 losing | 6.3 losing | 2.8 lost | | Copper | Barraud | 8 | Box | 6.8 losing | 8.0 losing | 1.2 lost | | Iron | Barraud | 2 | Box | 6.0 losing | 7.2 losing | 1.2 lost | | Ditto - Homeward bound | | 7.0 losing | | 6.2 losing | 0.8 gained | | Iron | Barraud | 1 | Box | 6.0 losing | 6.0 losing | No difference | | Ditto - Homeward bound | | 6.0 losing | | 5.2 losing | 0.8 gained | | Copper | Barraud | 8 | Box | 6.1 losing | 5.4 losing | 0.7 gained | | Iron | Barraud | 8 | Box | 1.8 gaining | 0.0 | 1.8 lost | | Iron | Same Chronom. | 8 | Box | 5.2 gaining | 5.5 gaining | 0.3 gained | | Iron | Barraud | 8 | Box | 0.4 losing | 0.0 | 0.4 gained | | Iron | Barraud | 8 | Box | 2.0 gaining | 1.6 gaining | 0.4 lost | | Iron | Barraud | 8 | Box | 0.0 | 0.4 gaining | 0.4 gained | | Barraud | | 8 | Box | 6.5 losing | 6.2 losing | 0.3 gained | | Next six months on ship its rate was | 6.5 losing | This Chronometer | | Copper | Barraud | 8 | Box | 2.7 losing | 1.9 losing | 0.8 gained | | Next twelve months on shore, its rate was | 0.1 gaining | On the Homeward passage the above Chronometers had the following rates given and found, after being on shore three months and two weeks. These Chronometers went regularly, but the rates on the Homeward passage were very irregular. It therefore appears that the Chronometers which went regularly on the outward passage did not keep their rates on the Homeward passage. These went regularly, but the rates on the Homeward passage were very irregular. This very indifferent performance of the Chronometers on the Homeward passage is probably owing to the manner in which they were used. On being landed at the Cape, the Chronometers were all found to be in good order. No difference. | Rates found. | Difference of Rates. | REMARKS. | |-------------|----------------------|----------| | 8.5 losing | 0.5 gained | These Chronometers were all rated at Madeira, and went steady at those rates on the passage out. | | 5.0 gaining | 2.0 gained | | | 6.0 losing | 1.5 lost | | | 9.0 losing | No difference | It therefore appears that these Timekeepers did not vary from the rates given them on shore in the smallest degree. | | 5.0 gaining | 1.8 gained | | | 7.0 losing | 4.6 gained | | | 16.5 then 22 gaining | 12.0 gained | These went regular with the rates found. This very indifferent during the whole voyage. | | 3.5 gaining | 1.3 gained | | | 6.3 losing | 2.8 lost | This Chronometer went steady at 6.3 till let down. | | 8.0 losing | 1.2 lost | On being landed, it returned to its first rate—6.8 losing. | | 7.2 losing | 1.2 lost | | | 6.2 losing | 0.8 gained | | | 6.0 losing | No difference | | | 5.2 losing | 0.8 gained | | | 5.4 losing | 0.7 gained | | | 0.0 | 1.8 lost | | | 5.5 gaining | 0.3 gained | | | 0.0 | 0.4 gained | | | 1.6 gaining | 0.4 lost | | | 0.4 gaining | 0.4 gained | | | 6.2 losing | 0.3 gained | This Chronometer returned to the maker's rate on being brought on shore. | | 1.9 losing | 0.8 gained | | | Date | Persons' Names | Ships' Names | Tonnage | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rate | |---------|----------------|-------------------------------|---------|-------------------------|------------------------|-----------------------|---------------|------| | 1817 | Capt. Sever | West India S. Fanny | 384 | Iron | Barraud | 8 | Box | 0.5 loss | | | Ditto | Ditto | | | Ditto | Next four months on shore | 0.2 gain | | | Ditto | Ditto | | | Ditto | Next two months on shore | 0.7 gain | | 1818 | Capt. James Kay| H. C. S. Marchioness of Exeter| 980 | Copper | Barraud | 8 | Box | 4.0 loss | | | | | | | Ditto | Next four months on shore | | | 1817 | Capt. R. S. Dalrymple | H. C. S. Vansittart | 1240 | Copper | Barraud | 8 | Box | 0.6 gain | | | Ditto | Ditto | | | Ditto | Next six months on shore | 0.4 loss | | | | | | | Ditto | Since the ship's return to London | | | 1817 & 1818 | Capt. Nairne | H. C. S. General Kyd | 1240 | Iron | Barraud | 2 | Box | 1.5 gain | | | | | | | Ditto | Next six months on shore | | | 1816 | Capt. R. Drew | West India Ship | | | Barraud | 2 | Box | 9.3 gain | | | Ditto | Ditto | | | Ditto | Next five months on shore | 8.4 gain | | | Ditto | Ditto | | | Ditto | Next three months on shore | 4.5 gain | | | | | | | Ditto | Next thirty-two days on shore | | | 1819 | Capt. Cookesley| Ship Malida | 480 | Copper | Barraud | 2 | Box | 6.5 loss | | | | | | | Ditto | Next forty days on shore | | | 1818 & 1819 | Capt. Johnson | H. C. S. Camden | 490 | Iron | Barraud | 2 | Box | Going n | | 1816 | Capt. Barwick | | | | Barraud | 2 | Box | 0.0 to | | | | | | | | On shore this Chronometer still increased to 11.5 gain | | | 1816 & 1817 | Capt. Tremenhire | H. C. S. Asia | 890 | Iron | Barraud | 8 | Box | 2.0 gain | | | | | | | Ditto | Next six months on shore | | | 1817 | Capt. Auber | E. I. S. Lady Raffles | 610 | Iron | Barraud | 2 | Box | 5.0 gain | | 1816 | Capt. Druce | | | | Barraud | 1 | Pocket | 2.5 loss | | 1815 & 1816 | Capt. Mortlock | H. C. S. Lowther Castle | 1200 | Copper | Barraud | 1 | Pocket | 1.8 loss | | 1819 & 1820 | Capt. Gribble | H. C. S. Princess Charlotte of Wales | 978 | Iron | Barraud | 8 | Box | 11.0 loss | | | | | | | | 8 | Box | 2.0 gain | | Iron or Copper fastened | Makers of Chronometers | No. of Days to wind up | Box or Pocket | Rates given | Rates found | Difference of Rates | |-------------------------|------------------------|------------------------|--------------|-------------|-------------|---------------------| | Iron | Barraud | 8 | Box | 0.5 losing | 0.9 gaining | 1.4 gained | | Ditto | | Next four months on shore | | | 2.0 gaining | 0.6 lost | | Ditto | | Next two months on shore | | | 1.4 gaining | 0.7 gained | | Ditto | | | | | 0.7 gaining | In this instance | | Copper | Barraud | 8 | Box | 4.0 losing | 4.1 losing | 0.1 lost | | Ditto | | Next four months on shore | | | 3.3 losing | | | Copper | Barraud | 8 | Box | 0.6 gaining | 0.2 gaining | 0.4 lost | | Ditto | | Next six months on shore | | | 0.7 losing | | | Ditto | | | | | 0.8 losing | | | Ditto | | Since the ship's return to England | | | 0.2 gaining | | | Iron | Barraud | 2 | Box | 1.5 gaining | 1.7 gaining | 0.2 gained | | Ditto | | Next six months on shore | | | 3.0 gaining | | | Barraud | | 2 | Box | 9.3 gaining | 10.3 gaining | 1.0 gained | | Ditto | | Next five months on shore | | | 8.4 gaining | | | Ditto | | | | | 8.9 gaining | | | Ditto | | Next three months on shore | | | 8.0 gaining | | | Ditto | | | | | 6.5 gaining | | | Ditto | | Next thirty-two days on shore | | | 5.0 gaining | | | Copper | Barraud | 2 | Box | 6.5 losing | 6.5 losing | No difference | | Ditto | | Next forty days on shore | | | 8.0 losing | | | Iron | Barraud | 2 | Box | Going mean time | 9.3 gaining | 9.3 gained | | Barraud | | 2 | Box | 0.0 to | 9.5 gaining | in the course of thirteen months | | On shore this Chronometer still increased to 11.5 gaining | | | | | 12.2 gaining | 0.7 gained | | And went at 12 months | | | | | | | | Iron | Barraud | 8 | Box | 2.0 gaining | 2.3 gaining | 0.3 gained | | Ditto | | Next six months on shore | | | 3.7 gaining | and was then cleaned. | | Iron | Barraud | 2 | Box | 5.0 gaining | 7.8 gaining | 2.8 gained | | Barraud | | 1 | Pocket | 2.5 losing | 3.4 losing | 0.9 lost | | And went next day | | | | | | | | Copper | Barraud | 1 | Pocket | 1.8 losing | 1.7 losing | 0.1 gained | | And went next day | | | | | | | | Iron | Barraud | 8 | Box | 11.0 losing | 12.2 losing | 1.2 lost | | 8 | Box | 2.0 gaining | | | 2.3 gaining | Since the ship's return to England | | | | | | | | | | Rates found. | Difference of Rates. | REMARKS. | |-------------|---------------------|----------| | 0.9 gaining | 1.4 gained | In this instance it returned to the same rate as on the preceding voyage. | | 2.0 gaining | 0.6 lost | | | 1.4 gaining | 0.7 gained | | | 4.1 losing | 0.1 lost | | | 3.3 losing | | | | 0.2 gaining | 0.4 lost | It therefore appears this Chronometer varied precisely the same quantity and the same way, two succeeding voyages: this ship, it may be necessary to remark, is copper fastened throughout. | | 0.7 losing | 0.4 lost | | | 0.8 losing | | | | 0.2 gaining | | | | 1.7 gaining | 0.2 gained | | | 3.0 gaining | | | | 10.3 gaining| 1.0 gained | | | 8.4 gaining | 0.5 gained | and then gradually decreased to 4.5, the rate when taken on board. | | 8.9 gaining | 2.0 gained | and was then cleaned. | | 8.0 gaining | | | | 6.5 gaining | | | | 5.0 gaining | | | | 6.5 losing | No difference | This Chronometer, since its return on board ship, has taken up again the rate of 6.5, which favours Mr. Fisher. | | 8.0 losing | | | | 9.3 gaining | 9.3 gained | This increase of rate took place very gradually during the first four months, after which it kept that rate, making an error of only 16", the following fifteen months, and continued the same rate for five months following on shore; was then cleaned. | | 9.5 gaining | in the course of thirteen months at sea, and the following two months. | | 12.2 gaining| 0.7 gained | And went at 12.2, gaining next threee months on shore. | | 2.3 gaining | 0.3 gained | | | 3.7 gaining | and was then cleaned.| | | 7.8 gaining | 2.8 gained | And went next four months on shore at 5.5 gaining | | 3.4 losing | 0.9 lost | And went next eleven months on shore at 0.3 losing. | | 1.7 losing | 0.1 gained | And went next forty days on shore at 2.1 losing; then cleaned. | | 12.2 losing | 1.2 lost | Since the ship's arrival it has been going at 14.8 losing. | | 2.3 gaining | 0.3 gained | 1.9 gaining. |