# A Voyage of Discovery and Research in the Southern and Antarctic Regions/Volume 2/Chapter 13

Deep Soundings; or, no Bottom with 4600 fathoms. Page 381.

#### CHAPTER XIII.

CHAPTER XIII.
The period of the season had now arrived at 1843 Feb. 1.which it became necessary, in order to prevent the ships being frozen into the pack, to give up any further attempt to penetrate it, more especially under the present unfavourable appearances; and, so soon as the gale abated and other circumstances suited, we began to make our way towards the clear water, which the sky indicated was at no great distance to the eastward. This, however, was not accomplished without some days of further labour and difficulty, owing to the thick weather and snow showers preventing our seeing the best leads through the pack.
At 6 p.m. on the 4th we got clear of the pack, in Feb. 4.latitude 64° 0′, and longitude 54° 0′, with which we had been so fruitlessly contending for a period of nearly six weeks; and truly rejoiced we all felt to be once more bounding freely over the high easterly swell, which the late gale had occasioned. We passed many pieces of heavy loose ice before midnight, but after that time were in perfectly clear water, with the exception of a few small bergs.
Our object now was to trace the pack edge to Feb. 5.the eastward, in the hope that by the time we reached the meridian of 40°, on which Weddell ​penetrated so far to the southward, we also should find the sea there so clear, as to admit of our yet attaining a high latitude: but the weather continuing thick, and a fresh breeze blowing from the east, we made only small progress, beating to windward—the loose ice near the pack edge always gave us timely notice of our approach to it: and the temperature of the sea was another sure guide.
Feb. 6.At noon on the 6th we were in latitude 63° 46′ S., longitude 52° 37′ W., the magnetic dip 62° 08′ S.; and at 1 p.m. we struck soundings in four hundred and eighty fathoms, on fine green sand. The birds were of the same kinds that I have so often enumerated as being found near the pack edge; seals were numerous, and one that we killed measured twelve feet two inches, and weighed 1145 lbs.
Beating to the eastward, along the pack edge, making about thirty miles daily, we were at Feb. 8.noon of the 8th in latitude 63° 49′ S., longitude 51° 07′ W., where we had no soundings with one thousand two hundred and ten fathoms. The temperature at that depth was 39°.5; at 600 fathoms, 37°.3; at 450 fathoms, 36.°4; at 300 fathoms, 35°.5; at 150 fathoms, 33°.2; at 100 fathoms, 32°.2; and at the surface, 32°.; but between the surface and one hundred fathoms the thermometers denoted that they had all passed through a stratum of water of the temperature of 29°.3. The specific gravity at the depth of 450 fathoms being the same as at the surface, 1.0274 at 33°.
Feb. 10.During the next three days we examined about ​one hundred and sixty miles of the pack, frequently entering the outer edge as far as we could without getting beset, without perceiving any opening in it by which we could penetrate to the south; and at noon, the 11th, were in latitude 64° 37′, and longitude 45° 39′; on the 14th we crossed Weddell's Feb. 14.track, in latitude 65° 13′ S., but under what different circumstances! he was in a clear sea: we found a dense, impenetrable pack; and as Admiral D'Urville was unable to attain even to the 64th degree, we must conclude that Weddell was favoured by an unusually fine season, and we may rejoice that there was a brave and daring seaman on the spot to profit by the opportunity.
Still pursuing our examination of the pack to the eastward, we crossed the line of no variation on the 22d, in latitude 61° 30′ S., and longitude about Feb. 22.22° 30′ W., where the magnetic dip being 57° 40′, gives the position of the magnetic pole in remarkable accordance with our previous determination; the circle of equal dip passing through New Zealand, and having the pole exactly half way between us and that place, seems satisfactorily to confirm my previous suggestion, that there is but one pole of verticity in the southern hemisphere, not very distant from the place computed by Gauss, but much more remote from the spot he had assigned to it, and where I was directed to seek for it. We had no soundings with seven hundred and fifty ​fathoms, the temperature at that depth being 39°.2, that of the surface, 32°; we found the current setting N.60° E. ten miles per diem.
From this point the pack trended more to the Feb. 26.southward of east, so that by noon the 26th we were in latitude 64° 38′ S., and longitude 12° W. the dip 60° 50′ S., and variation 6° W. It was blowing strong from the north-east, with a heavy swell and a thick fog, which obliged us to keep a good offing from the pack, under our lee. Feb. 27.Throughout the whole of the next day the snow was so thick that we could not see half a mile before us, and had great difficulty in keeping the ships together, especially in passing through a cluster of large bergs, shortly before dark: we had afterwards long intervals of clearer weather between the snow showers; and even derived considerable assistance from diffused auroral light, which appeared from south-west to south-east, in small patches.
Feb. 28.When day broke we made all sail, anxious to take advantage of the fine clear sea in which we were navigating. The pack, having suddenly turned off to the southward, could not now be seen; and we began to hope we had reached its eastern limits. Steering to the south-east, we crossed the 66th degree of latitude, in 7° west longitude, shortly before noon, when the wind veered round to the south-eastward; and being within one hundred miles of the route by which the Russian navigator, Bellinghausen, in January, 1820, reached the latitude of 69°¾ S., in 2° west ​longitude, and being assured that no considerable portion of land could lie between our tracks, I considered it would be a waste of time to follow his footsteps up to that latitude, should it even at this late period of the season prove attainable; I therefore preferred devoting the few remaining days of the navigable season to exploring between those meridians upon which we had been permitted to carry our researches so many degrees to the southward of any of our predecessors. We accordingly tacked at 3 p.m., and stood to the south-west. Thick weather prevailed throughout the rest of the day and greater part of the night, during which we saw only a few pieces of ice and no bergs, which gave us the more confidence in carrying sail, a rather hazardous proceeding, which nothing but the urgency of the case could justify; and daylight again appeared without our having occasion to regret having adopted it.
ABSTRACT OF THE METEOROLOGICAL JOURNAL KEPT ON BOARD HER MAJESTY'S SHIP EREBUS.—FEBRUARY, 1843.
| Day. | Position at Noon. | Position at Noon. | Position at Noon. | Position at Noon. | Temperature of the Air in Shade. | Temperature of the Air in Shade. | Temperature of the Air in Shade. | Mean Tempera- ture of Sea at Surface. | Temp. at 9 a.m. | Temp. at 9 a.m. |
| Day. | Lat. S. | Lat. S. | Long. W. | Long. W. | Max | Min. | Mean. | Mean Tempera- ture of Sea at Surface. | Air in Shade | Dew point. |
| 1 | 63 | 59 | 55 | 20 | 35 | 29.5 | 32.1 | 32.0 | 29 | 29* |
| 2 | 64 | 16 | 55 | 22 | 33.5 | 28.5 | 31.5 | 31.5 | 32.5 | 26 |
| 3 | 64 | 17 | 55 | 40 | 29.5 | 27.5 | 28.6 | 30.8 | 28 | 27 |
| 4 | 64 | 10 | 54 | 47 | 31 | 26 | 29.0 | 30.7 | 29 | 24 |
| 5 | 63 | 30 | 53 | 01 | 32 | 30 | 31.1 | 32.2 | 32 | 28 |
| 6 | 63 | 46 | 52 | 37 | 32 | 30 | 31.1 | 31.9 | 31.5 | 29 |
| 7 | 64 | 08 | 51 | 53 | 32.5 | 30 | 31.6 | 317 | 32 | 32* |
| 8 | 63 | 49 | 51 | 07 | 35.5 | 31 | 33.0 | 32.6 | 33 | 33* |
| 9 | 64 | 19 | 50 | 24 | 35.5 | 30.5 | 32.0 | 31.6 | 35 | 31 |
| 10 | 64 | 31 | 47 | 44 | 32.5 | 30 | 30.9 | 30.1 | 31 | 27.5 |
| 11 | 64 | 37 | 45 | 39 | 31 | 28 | 30.0 | 30.1 | 30 | 28.5 |
| 12 | 64 | 39 | 43 | 56 | 31.5 | 28 | 29.7 | 29.7 | 30 | 25.5 |
| 13 | 64 | 56 | 42 | 59 | 32.5 | 29.5 | 30.8 | 30.1 | 30 | 30* |
| 14 | 65 | 06 | 41 | 14 | 35.5 | 30 | 31.7 | 30.3 | 33 | 30 |
| 15 | 64 | 40 | 39 | 28 | 30 | 28 | 29.5 | 30.2 | 30 | 26 |
| 16 | 63 | 56 | 38 | 17 | 30 | 28 | 28.7 | 29.6 | 29 | 25 |
| 17 | 63 | 36 | 35 | 24 | 29.5 | 27.5 | 28.6 | 29.1 | 28.5 | 26 |
| 18 | 62 | 39 | 31 | 44 | 32 | 28.5 | 30.4 | 30.2 | 31 | 30 |
| 19 | 62 | 16 | 29 | 00 | 30.5 | 28 | 29.2 | 29.6 | 29.5 | 25 |
| 20 | 61 | 59 | 26 | 17 | 32 | 28 | 30.1 | 30.1 | 32 | 32* |
| 21 | 61 | 51 | 24 | 00 | 32 | 29 | 29.5 | 30.1 | 29 | 29* |
| 22 | 61 | 37 | 21 | 51 | 31.5 | 29.5 | 30.0 | 30.1 | 30 | 21 |
| 23 | 61 | 46 | 18 | 58 | 30.5 | 28 | 28.9 | 30.7 | 29 | 29* |
| 24 | 62 | 36 | 15 | 52 | 31 | 27.5 | 28.8 | 30.4 | 30.5 | 26 |
| 25 | 64 | 10 | 14 | 19 | 32 | 29.5 | 31.3 | 31.0 | 32 | 32* |
| 26 | 64 | 38 | 12 | 00 | 35 | 32 | 32.6 | 31.8 | 33 | 33* |
| 27 | 65 | 12 | 9 | 55 | 33 | 32 | 32.4 | 32.0 | 32 | 32* |
| 28 | 66 | 01 | 6 | 53 | 34 | 32 | 32.5 | 32.5 | 33 | 33* |
| | | | | | 33.5 | 27.5 | 30.56 | 30.88 | | |
* Deposit of rain, or snow, or fog.
ABSTRACT OF THE METEOROLOGICAL JOURNAL KEPT ON BOARD HER MAJESTY'S SHIP EREBUS.—FEBRUARY, 1843.
| Day. | Barometer. | Barometer. | Barometer. | Winds. | Winds. | Winds. | Winds. | Winds. | Winds. | Weather. | Weather. | Weather. |
| Day. | Max. | Min. | Mean. | Direction. | Direction. | Direction. | Force. | Force. | Force. | | | Weather. | Weather. | Weather. |
| | Inches. | Inches. | Inches. | | | | | | |
| 1 | 29.31 | 28.952 | 29.107 | | S. Westerly | | | 4 | | | 1 b.c.p.s.q.* | |
| 2 | .593 | 29.321 | .497 | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. S.S.W. p.m. East. | $\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,$ | | 3 2 | $\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,$ | | 0 m.s. | |
| 3 | .597 | .508 | .545 | | East | | | 5 | | | 0 l.s. | |
| 4 | .495 | .339 | .403 | | S.E.E. | | | 4 | | | 0 p.s. | |
| 5 | .338 | .163 | .244 | | E.S.E. | | | 5 | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 1 b.c.g. p.m. 0 s.q. | |
| 6 | .304 | .228 | .264 | | E.N. | | | 3 | | | 0 m.f.p.s. | |
| 7 | .373 | .263 | .320 | | East | | | 2 | | | 0 m.s.f. | |
| 8 | .456 | .356 | .392 | | N.Easterly | | | 2 | | | 0 m.f. | |
| 9 | .495 | .450 | .476 | | N.E. | | | 2 | | | a.m. 1 b.c.o.g. | |
| 10 | .451 | .228 | .360 | | North | | | 2 | | | 0 g.p.s. | |
| 11 | .190 | 28.961 | .041 | | Easterly | | | 4 | | | 0 g.p.s. | |
| 12 | .199 | .988 | .064 | | S.E. by E. | | | 3 | | | 1 b.c.p.s. | |
| 13 | .470 | 29.217 | .334 | | E.N.E. | | | 2 | | | 1 b.c.p.s | |
| 14 | .512 | .389 | .478 | | N.Easterly | | | 2 | | | 1 b.c.g.p.s. | |
| 15 | .371 | .148 | .247 | | East | | | 5 | | | 0 g.p.s. | |
| 16 | .283 | .160 | .210 | | S. Easterly | | | 4 | | | 2 b.c.g.q.p.s. | |
| 17 | .362 | .268 | .337 | | S.S.E. | | | 4 | | | 0 g.p.s. | |
| 18 | .295 | .182 | .217 | | S.E. | | | 3 | | | 0 g.p.s. | |
| 19 | .253 | .225 | .236 | | South | | | 4 | | | 0 g.p.s. | |
| 20 | .377 | .255 | .311 | | Easterly | | | 2 | | | 0 f.s. | |
| 21 | .527 | .342 | .404 | | S.S.E. | | | 4 | | | 0 g.p.s. | |
| 22 | .637 | .545 | .553 | | Southerly | | | 2 | | | 0 | |
| 23 | .599 | .486 | .543 | | S.W. | | | 4 | | | 0 g.q.p.s. | |
| 24 | .702 | .527 | .651 | | S.W. by W. | | | 4 | | | 0 g. | |
| 25 | .491 | 28.614 | .010 | | North | | | 6 | | | 0 g.m.q.p.s. | |
| 26 | 28.604 | .435 | 28.504 | | N. by E. | | | 3 | | | 0 m.f.p.r.s. | |
| 27 | .716 | .481 | .614 | | S.S.W. | | | 2 | | | 0 p.s. | |
| 28 | .958 | .712 | .830 | | Southerly. | | | 4 | | | 0 m.s. | |
| | 29.702 | 28.435 | 29.2568 | | | | 3.34 | 3.34 | 3.34 | | | |
* For explanation of these symbols, see Appendix to Vol. I.
​oceanic blue to a light olive brown. At noon we were in latitude 67° 6′ S., longitude 9° W., magnetic dip 62° 42′ S., variation 8° 12′ W. The evening was fine, and with a fresh breeze from S.E. we made good progress to the S.W., passing only a few bergs and some straggling pieces of ice. The stars shone with great brilliancy during the night, a sight we had not witnessed for a long time, having been obscured during the last month by almost continual fog and snow; indeed, there were only three days in which we were not assailed by snow showers.
March 2.Beautiful as had been the night, the morning broke still more splendidly; the sun rose out of the horizon bright and clear; and as the day advanced the effects of his rays, feeble as they were, from their obliquity, had an animating influence on us all who had not seen his unclouded face for a space of nearly six weeks. It afforded me the opportunity I had long desired, of obtaining actinometric observations, in which, with the assistance of Commander Bird, I succeeded, and completed two sets of experiments with each of two different instruments; by which the absolute value of the sun's radiating power in these latitudes can be accurately determined.
At noon our latitude was 68° 14′ S., longitude 12° 20′ W., magnetic dip 63° 28′ S., and variation 6° 3′ W. Numerous fragments of bergs were passed, from which we might have replenished our almost exhausted store of water, but the sea was ​running so high, although there was only little wind, that I could not venture to lower the boats.
At 3 p.m. clouds rose slowly from the eastward, and concealed from our view the blue vault of heaven, excepting only a space of about twenty degrees, in which the sun went down more gorgeously than he arose.
Light baffling winds continued throughout the evening, greatly retarding our progress at a time when every hour was of importance, and it required much reflection upon past mercies to prevent a feeling of impatience at the delay arising in our minds.
The sky had become darkened by dense snow clouds; and the threatening appearance to the N.E. led us to expect that unfavourable weather would follow, but in this we were mistaken. After a gentle air from the S.W., which dispersed the March 3clouds, it fell perfectly calm; and the swell having subsided, the boats were lowered to try for soundings. Owing to our having always struck ground in less than two thousand fathoms in other parts of the Antarctic ocean, we, unfortunately, had only four thousand fathoms of line prepared, the whole of which ran off the reel without reaching the bottom. The temperature at 1050 fathoms was 39°.5; at 900 fathoms, 39°.; at 750 fathoms, 39°.4; at 600 fathoms, 38°.7; at 300 fathoms, 35°.5; at 150 fathoms, 33°.; and at the surface, 30°.8. The specific gravity at 150 and 600 fathoms was 1.0283 at 38°; and of the surface, 1.0278 at 32°. ​The current was setting to the S.W. at the rate of seven miles daily.
We were at this time in latitude 68° 34′ S., longitude 12° 49′ W., magnetic dip 63° 24′ S., and variation 5° 24′ W.
The great depth of the ocean served to relieve us from every apprehension of being obstructed by land, and at the same time to inspire a hope that we might still find a clear sea very far to the south, for Davis has shrewdly observed, "the deep sea fryseth not;" the cause of which we now find in the constant supply of heat from beneath; although the period of the year had arrived, when our former experience had led us to consider the higher southern latitudes as sealed from the intrusion of man.
A light wind sprang up at 4.30. p.m., from the westward, which increased to a fresh breeze from the north-west before midnight, and we carried all sail, steering south-west; the sky was overcast, but we could see to the distance of five or six miles after March 4.day broke. At noon our latitude was 69° 27′ S., longitude 14° 29′ W., magnetic dip 64° 5′. In the afternoon it became more clear; the sun broke through the clouds, and we got observations for the variation, of great interest as they enabled us to trace the line of no variation to the southward. At 6 p.m. we had passed the highest latitude attained by Bellinghausen, about midway between his track and Weddell's; and at 9 p.m. we crossed the 70th degree of latitude. ​Snow showers now became frequent, and many bergs were seen; the white petrel also appeared in great numbers, indicating our approach to the pack; but we pursued our course under all sail, the night being fine and the sea smooth.
In the morning we had constant snow and hazy March 5.weather; and at 8.30. a.m., whilst running with all studding sails set, the main pack was seen from S.W. by S. to W.N.W. We immediately shortened sail and altered the course, at first to south, and then to S.E., running along from point to point of the pack. At noon our latitude was 71° 10′ S., longitude 15° 47′ W., at which time we were passing much loose ice off the pack edge, which now extended from east, round by south to W.N.W., so that we could not proceed further south without entering it. The outer edge appearing very open from the mast-head, we ran the ships into it as far as we prudently could; and at four o'clock, after penetrating about twenty-seven miles, we found it so close and heavy, and the holes of water amongst it so covered with newly formed ice, that we were obliged to haul to the wind, and endeavour to work our way out again, which we had some difficulty in doing, as the wind had freshened considerably, and was blowing directly on to the pack. When at our farthest we were in latitude 71° 30′ S., longitude 14° 51′ W.: a cask was then thrown overboard, containing a paper signed by myself and all the officers, stating the fact.
​The barometer falling rapidly, indicated an approaching gale; and with the pack under our lee, we were obliged to carry all sail, to gain an offing as speedily as possible. The season was now too far advanced to attempt any further examination of the pack, therefore I made the signal to the Terror of my intention to proceed to the Cape of Good Hope; and having hoisted our colours, we began to retrace our steps, and before dark regained the clear water. Here we found the gale blowing in violent squalls, attended with constant snow; and, notwithstanding the great hazard of doing so, amongst the numerous bergs that surrounded us, we were obliged to carry a heavy press of sail throughout the night; after all, we were scarcely March 6.able to hold our ground, for at daylight the pack was seen through the haze and thick snow, at about a quarter of a mile from us, under our lee, presenting to view a line of foaming breakers. We immediately wore to the eastward; the gale increasing, and the sea running very high, we endeavoured to beat off under treble-reefed topsails and reefed courses; but again the pack appeared a-head and to leeward in the evening, proving to us that we were completely embayed. Fortunately, the gale was driving the pack before it, at about the same rate that we were dropping down upon it. We wore and stood to the eastward, under all the sail we could possibly carry; our masts, though aided by additional supports, quivered to every sea that broke over the ship, and the ​sprays freezing as they fell upon the rigging and decks, rendered it difficult to work the ropes, while the extreme darkness of the night kept us in continual apprehension of collision with some of the bergs which at times it seemed almost impossible to avoid.
I need not say it was a night of deep anxiety to us all: and the necessary degree of composure and peace of mind required to meet it, could only result from a firm reliance upon the guidance and protection of Almighty God, who had preserved us under equally perilous circumstances.
Throughout this fearful night and the whole of March 7.the next day, we could not perceive the least mitigation of the gale; but it favoured us by veering rather more to the eastward; soon after dark, when we were preparing to pass another anxious night, the wind suddenly abated, and at midnight we had a light air from the westward. A calm March 8. of six hours' duration succeeded; after which the north-east wind came on with scarcely less fury than before; but by our observations we found we had gained some ground, and had no longer any dread of being driven down upon the pack. At noon our latitude was 70° 28′ S., longitude 17° 21′ W., magnetic dip 65° 1′ S., variation 0°.16′ W. Our only remaining difficulty now, was to avoid the bergs with which, as during the former gale, we were several times nearly in collision; the heavy sea which broke against the perpendicular face of one of them fell on board our ​ship. Too much praise cannot be bestowed upon Captain Crozier and his officers, for the seamanlike manner in which the Terror was conducted and maintained her station throughout these severe gales; and the vigilance, activity, and cool courage displayed by Commander Bird, and the rest of my companions, deserve the expression of my high admiration.
March 9.By daylight the next morning the wind had veered to the E.S.E., but the heavy swell occasioned by the N.E. gale prevented our making such good way in that direction as we otherwise should have done. At noon our latitude was 69° 38′ S., longitude 15° 43′ W.
The whole of the rest of the day and during the night the storm still raged, and kept us anxiously on the look out to avoid the bergs; and it can never cease to be a source of wonder and gratitude that we escaped running against them.
March 10.We kept under easy sail during the night; but as soon as day broke we set all that the ships could carry, steering to the north-east. The wind moderated towards noon, and the fine day which followed was one of real enjoyment, after the almost uninterrupted succession of gales and thick weather we had experienced during the past week.
At 9 p.m. a remarkable ray of light was seen between two dark clouds; it was mentioned in the log-book as a stationary beam of Aurora Australis, bearing west, and inclined in an angle of about 45° to the southward. It was seen frequently ​during the few following nights, and its fixed character at length assured us that it must be the tail of a comet, which eventually proved to be the case. It was seen a few days sooner than by us at the Cape of Good Hope, St. Helena, and Barbadoes; but not until the 17th of March in Europe, where Sir John Herschel published the earliest notice of it, designating it as a "Comet of enormous magnitude in the course of its progress through our system, and at present not far from its perihelion."
At 6.30. a.m. we recrossed the Antarctic circle for the last time, in longitude 13° 30′ W., and by noon were in latitude 65° 56′ S., and longitude March 11.13° 36′ W., having made good a course of N. 17° E., one hundred and thirty-six miles, since noon of yesterday.
As we must necessarily pass near Bouvet Island, which has been so frequently sought in vain, our course was shaped so as to get into its supposed latitude at about ten degrees to the westward, that we might, by sailing to the eastward on that parallel, ascertain its position with some degree of precision. We had a succession of strong S.W. gales, and passed a great number of bergs, which obliged us to proceed under reduced sail during the long dark nights of this late season of the year.
On the 15th and 18th, we had opportunities of March 18.trying the temperature of the sea, which we found at 600 fathoms to be 39°; at 450 fathoms, 37°.8; at 300 fathoms, 36°.8; at 150 fathoms, 35°.2; at ​the surface 33°.5; in both cases the mean latitude being 56° 41′ S., and longitude 6° 5′ W.
March 19.At 6 p.m. the following day, being in the latitude of Bouvet Island, 54° 21′ S., and about three hundred miles west of its assigned position, our course was altered to true east; the number of bergs had greatly diminished, and having fine clear weather, we continued, throughout the night, under all sail.
During the next two days it blew a gale from the N.W., and for the first time we had rain instead of snow, the temperature having risen to 37. As we were now approaching Bouvet Island, we rounded to every night, lest we should either run upon, or pass it in the dark.
March 20.At noon, the 20th, we crossed the meridian of Greenwich, in latitude 54° 7′ S., and pursuing a true east course, were in longitude 2° 50′ E. the March 21.next day at noon. Many bergs of large size were seen during the last two days, and were the occasion of frequent false reports of land.
At 8 p.m. we were in latitude 54° 8′., and longitude 4° 36′ E.; only fifty-eight miles from the island, as placed on the Admiralty chart. We hove to for the night under a close-reefed main-top-sail, the sea running very high, and many bergs about us. Every two hours we tried for, but did not obtain soundings, with 400 fathoms.
March 22.At daylight we bore away before the gale, which had not abated in the smallest degree, and the sea had gained a mountainous height; the weather, ​however, was clear, so that we could see the bergs at a distance of three or four leagues. At noon, by observation, our latitude was 54° 11′ S., and longitude 6° E. Bouvet Island should, therefore, have been in sight, bearing S. 55° E., distant nine miles. We stood exactly for it, until we had run twelve miles, but not seeing it, we steered east, to keep in its supposed latitude: after having gone forty miles further, we arrived at the spot from which Cook sought it to the eastward, and the night getting dark, I gave up all further search, concluding, with him, that M. Bouvet had mistaken a large iceberg for land. I have now, however, reason to believe that there is an island in that vicinity; for since my return to England, I have learned from C. Enderby, Esq. that it has been visited by several of his vessels, and that a party from one of them actually landed, and was compelled by stormy weather to remain nearly six days on the island, and brought on board several seals, which they had killed on its S.W. point.
The log-book of the Sprightly, Captain Norris, is now before me, from which I quote the following passages:—"10th December, 1825. The island is in latitude 54° 15′ S., longitude by chronometer 5° E.; and, as we are now certain it is an island, we name it Liverpool Island. It appears to extend three or four leagues from north to south; the north end high and rugged, the south end low, the middle high, and covered with snow."
There is a pencil drawing of the island, bearing ​west five or six leagues. The log says, "The captain got within a cable length of the shore, but owing to the steepness of the rocks, and the weather coming on thick, with much sleet and snow, was the whole and sole reason of not making a successful landing."
On the 13th they met with another island, of which is said, "This island, which we have named Thompson Island, bears about N.N.E., fifteen leagues from Liverpool Island; there are also three rocks, which we named the Chimnies, to the S.W., four or five miles from Thompson Island; and another rock three miles to the southward of them. The island is in latitude 53° 56′ S., longitude 5° 30′ E."
We read, "16th December, P.M., fresh breezes and cloudy. The Lively (the consort of the Sprightly), by order, hoisted out her boat, and we manned her out of both vessels and sent her on shore, to endeavour to find a landing at the west end of the island. We sounded on its south side, and found from thirty-five to twenty fathoms, black sandy bottom, at a mile from the shore. Caught a number of small fish, resembling codfish. At 8 p.m. the boat returned, having hoisted the union jack on the shore, &c.
"On the 18th p.m., the captain gave orders for a boat to be manned from each vessel, one to go one way round the isle and one the other, and to meet at the west end."
Stormy weather almost immediately followed ​the landing of the boats, and it was not until the 24th the boats could regain the ships. They brought the skins of forty-eight seals they had killed on the island. And the log says, "We found by their report that seals are very scarce; and the isle is not likely to produce many, the S.W. point being the only place where they can make a landing, as the boats went entirely round the isle, and nothing but perpendicular rocks could be seen; it bears evident marks of having been a volcano, as it is nothing less than a complete cinder, with immense veins of lava, which have the appearance of black glass, though some are streaked with white."
Captain James Lindsay, in the Swan sealer, also belonging to Messrs. Enderby, endeavoured to approach an island which they saw in latitude 54° 24′ S., and longitude 3° 15′ E., on the 7th of October, 1808; but after persevering for several days, and running great hazard, they were unable to penetrate the floes and loose ice by which it was surrounded, and abandoned the attempt. His description of the island, as well as the position he assigns it, differs so much from Captain Norris's, that it was certainly not the same as that upon which his people landed. He says, "The west point of the island is high and steep, the east point low and level, covered with snow; it appears about five miles from east to west, and the close ice surrounds it to the distance of three miles from its shores."
​From these statements it would appear that there is probably more than one island in this neighbourhood, but certainly not in the positions given in their log-books; for although unaware of these accounts at the time we were in search of Bouvet Island, we passed so near as certainly to have seen them had they been there. It would be very desirable that their number and situation should be accurately determined, which might easily be done by a small vessel from the Cape of Good Hope. The proper season for this service is the middle of December, when the nights are short, and the finest weather may be expected.
March 25.We continued to experience very boisterous weather, and passed numerous bergs in our passage to the Cape, until noon of the 25th, when we were in latitude 47° 40′ S., longitude 10° 51′ E., magnetic dip 55° 53' S. and variation 25° 29′ W., where the last iceberg was seen.
March 27.On the 27th, in latitude 43° 52′ S., longitude 13° 23′ E., we found the temperature of the sea at 600 fathoms to be 39°.5; at 450 fathoms, 39°.8; at 300 fathoms, 40°3; at 150 fathoms, 44°; at the surface 47°.5. We were, therefore, very much to the northward of the circle of uniform temperature of the ocean throughout its entire depth, and must have crossed it in about the latitude of 52°, and longitude 9° E. I very much regretted that the tempestuous weather prevented our making experiments in that locality.
​We had previously crossed this circle at the following six different points, viz.:—
| Date. | Date. | | Latitude. | Latitude. | Latitude. | Longitude. | Longitude. | Longitude. | Reference to Narrative. | Reference to Narrative. |
| 1840. | Dec. 21 | - | 57° | 52′ | S. | 170° | 30′ | E. | Vol. I. | p. 166 |
| 1841. | March 30 | - | 55 | 09 | | 132 | 20 | | Vol. I. | p. 317 |
| {{{1}}}„ | Dec. 13 | - | 55 | 18 | | 149 | 20 | W. | Vol. II. | p. 140 |
| 1842. | March 23 | - | 58 | 36 | | 104 | 40 | | Vol. II. | p. 227 |
| {{{1}}}„ | Sept. 16 | - | 54 | 41 | | 55 | 12 | | {{{1}}}„ | p. 282 |
| {{{1}}}„ | Dec. 20 | - | 55 | 48 | | 54 | 40 | | {{{1}}}„ | p. 322 |
| Mean Latitude | Mean Latitude | - | 56 | 14 | S., or if we consider the latter two as one point, 56° 26′ | S., or if we consider the latter two as one point, 56° 26′ | S., or if we consider the latter two as one point, 56° 26′ | S., or if we consider the latter two as one point, 56° 26′ | S., or if we consider the latter two as one point, 56° 26′ | S., or if we consider the latter two as one point, 56° 26′ |
It is, therefore, evident that about this parallel of latitude there is a belt or circle round the earth, where the mean temperature of the sea obtains throughout its entire depth, forming a boundary, or kind of neutral ground, between the two great thermic basins of the ocean. To the north of this circle the sea has become warmer than its mean temperature, by reason of the sun's heat, which it has absorbed, elevating its temperature at various depths in different latitudes. So that the line of mean temperature of 39°.5, in latitude 45° S., has descended to the depth of 600 fathoms; and at the equatorial and tropical regions, this mark of the limit of the sun's influence is found at the depth of about 1200 fathoms; beneath which the ocean maintains its unvarying mean temperature of 39°.5, whilst that of the surface is about 78°.
ABSTRACT OF THE METEOROLOGICAL JOURNAL KEPT ON BOARD HER MAJESTY'S SHIP EREBUS.—FEBRUARY, 1842.
| Day. | Position at Noon. | Position at Noon. | Position at Noon. | Position at Noon. | Temperature of the Air in Shade. | Temperature of the Air in Shade. | Temperature of the Air in Shade. | Mean Tempera- ture of Sea at Surface. | Temp. at 9 a.m. | Temp. at 9 a.m. |
| Day. | Lat. S. | Lat. S. | Long. W. | Long. W. | Max | Min. | Mean. | Mean Tempera- ture of Sea at Surface. | Air in Shade | Dew point. |
| 1 | 67 | '06 | 8 | 35 | 32 | 25.5 | 30.6 | 31.8 | 31 | 26 |
| 2 | 68 | 14 | 12 | 20 | 29 | 26 | 27.5 | 30.7 | 27 | 18 |
| 3 | 68 | 34 | 12 | 49 | 30.5 | 28 | 29.4 | 30.6 | 30 | 18.5 |
| 4 | 69 | 26 | 14 | 29 | 31.5 | 29 | 30 | 30.7 | 30 | 21 |
| 5 | 71 | 10 | 15 | 47 | 32 | 29 | 30.1 | 30.4 | 30 | 30* |
| 6 | 71 | '09 | 15 | 39 | 30 | 29 | 30.2 | 30.4 | 30 | 30* |
| 7 | 70 | 36 | 16 | 42 | 30.5 | 28.5 | 29.9 | 30.1 | 30 | 30* |
| 8 | 70 | 28 | 17 | 21 | 30.5 | 27 | 287 | 30 | 30 | 30* |
| 9 | 69 | 38 | 15 | 43 | 27.5 | 25 | 26.4 | 30 | 27 | 27* |
| 10 | 68 | '06 | 15 | 20 | 29 | 24.5 | 26.8 | 30.1 | 25 | 22 |
| 11 | 65 | 56 | 13 | 10 | 30 | 27.5 | 28.8 | 30.6 | 29 | 23 |
| 12 | 63 | 57 | 13 | 36 | 33 | 29.5 | 30.8 | 31.4 | 32 | 28 |
| 13 | 61 | 34 | 11 | 23 | 31 | 29 | 29.4 | 32.3 | 31 | 24.5 |
| 14 | 59 | 16 | 9 | 19 | 31 | 28 | 29.4 | 31.5 | 30 | 16 |
| 15 | 57 | 27 | 7 | 52 | 36 | 29 | 30.8 | 33 | 32 | 18 |
| 16 | 57 | '09 | 7 | 15 | 33.5 | 29 | 30.6 | 33.3 | 31 | 26 |
| 17 | 56 | 38 | 6 | 16 | 34 | 30.5 | 32.2 | 33.3 | 31 | 30* |
| 18 | 55 | 56 | 4 | 19 | 34 | 32 | 33.2 | 33.5 | 34 | 31.5 |
| 19 | 54 | 31 | 2 | 25 | 34 | 32 | 32.8 | 33.4 | 33 | 33* |
| 20 | 54 | '07 | 0 | 0 | 36 | 32 | 34 | 33.4 | 34 | 20.5 |
| | | | East. | East. | | | | | | |
| 21 | 54 | '05 | 2 | 50 | 37 | 33.5 | 35.5 | 33.4 | 37 | 37* |
| 22 | 54 | 11 | 6 | '01 | 35 | 32 | 33.4 | 33.5 | 35 | 35* |
| 23 | 52 | 31 | 8 | '08 | 36 | 33 | 34 | 34.3 | 33 | 33* |
| 24 | 50 | 18 | 9 | 15 | 38.5 | 34 | 37 | 37.3 | 36 | 31 |
| 25 | 47 | 38 | 10 | 51 | 44 | 38 | 40.7 | 41.1 | 41 | 38 |
| 26 | 45 | 32 | 11 | 54 | 47 | 42 | 45 | 44.2 | 44 | 44 |
| 27 | 43 | 52 | 13 | 23 | 52.5 | 47.5 | 49.8 | 47.5 | 50 | 49 |
| 28 | 43 | 10 | 14 | 44 | 57 | 49.5 | 52.7 | 50.6 | 52 | 50.5 |
| 29 | 41 | 48 | 15 | '09 | 58 | 50 | 52.7 | 54.5 | 54 | 54 |
| 30 | 39 | 56 | 15 | 52 | 61 | 51.5 | 55.3 | 63.9 | 55 | 52 |
| 31 | 37 | 40 | 16 | 40 | 67 | 62 | 64.9 | 65.2 | 66 | 55 |
| | | | | | 67 | 24.5 | 35.57 | 36.65 | | |
* Deposit of rain, or snow, or fog.
ABSTRACT OF THE METEOROLOGICAL JOURNAL KEPT ON BOARD HER MAJESTY'S SHIP EREBUS.—MARCH, 1843.
| Day. | Barometer. | Barometer. | Barometer. | Winds. | Winds. | Winds. | Winds. | Winds. | Winds. | Weather. | Weather. | Weather. |
| Day. | Max. | Min. | Mean. | Direction. | Direction. | Direction. | Force. | Force. | Force. | | | Weather. | Weather. | Weather. |
| | Inches. | Inches. | Inches. | | | | | | |
| 1 | 29.118 | 28.951 | 29.016 | | S.S.E. | $\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,$ | | 4 | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 0 p.s.* p.m. 3 b.c. | |
| 2 | .217 | 29.089 | .173 | | Southerly | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 3 p.m. 1 | $\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,$ | | 4 b.c. | |
| 3 | .260 | .192 | .210 | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. S.S.W. p.m. Nthly. | $\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,$ | | 1 | | | 0 g. | |
| 4 | .285 | .228 | .264 | | N.W. | | | 3 | | | 0 g.p.s. | |
| 5 | .213 | 28.809 | .022 | | N. Easterly | | | 4 | | | 0 s. | |
| 6 | 28.885 | .742 | 28.808 | | N.E. | | | 7 | | | 0 q.g.p.s. | |
| 7 | 29.098 | .798 | .897 | | E. by N. | | | 7 | | | 0 q̣.f̣.ṣ. | |
| 8 | .262 | 29.125 | 29.2 | | N.E. by E. | | | 4 | | | 0 q.p.s. | |
| 9 | .253 | .053 | .148 | | E. by S. | | | 6 | | | 0 q.p.s. | |
| 10 | .135 | .013 | .072 | | S.E. | | | 6 | | | 1 b.c.o.p.s. | |
| 11 | .130 | 28.52 | 28.86 | | East | | | 4 | | | 0 p.s. | |
| 12 | .113 | .441 | .690 | | S.S.E. | | | 5 | | | 2 b.c.q.p.s. | |
| 13 | .481 | 29.122 | 29.34 | | S.W. | | | 5 | | | 0 g.q.p.s. | |
| 14 | .558 | .460 | .499 | | S.W. by W. | | | 4 | | | 0 g.p.s. | |
| 15 | .653 | .473 | .637 | | S. Westerly | | | 2 | | | 2 b.c.p.m. | |
| 16 | .449 | .268 | .340 | | N. Easterly | | | 2 | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 0 g.p.s. p.m. 3 b.c. | |
| 17 | .351 | .254 | .303 | | N.N.E. | | | 3 | | | 0 g.p.s. | |
| 18 | .365 | .142 | .270 | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. N.W. p.m. S.E. | bracer | | 3 | | | 0 g.m.p.s. | |
| 19 | .664 | .113 | .302 | | S. by E. | | | 6 | | | 0 g.q.p.s. | |
| 20 | .827 | .414 | .711 | | N. Westerly | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 2 p.m. 6 | | | 3 b.c.g. 0 q̣.p.s.r. | |
| 21 | .529 | .009 | .293 | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. N.W. p.m. West. | | | 8 9 | | | 0 g.q̣.r. 3 b.c.q̣.p.s. | |
| 22 | .373 | .095 | .191 | | W.N.W. | | $\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$ | a.m. 9 p.m. 10 | | | 0 g.q̣.p.s. 1 b.c.q̣.p.s.m. | |
| 23 | .699 | .118 | .415 | | W. by S. | | | 8 | | | 1 b.c.q.s. | |
| 24 | 30.239 | .720 | 30.053 | | W.S.W. | | | 6 | | | c.q.p.m. | |
| 25 | .362 | 30.223 | .292 | | N.W. by W. | | | 6 | | | 1 b.c.g.q. | |
| 26 | .438 | .300 | .367 | | N.W. | | | 5 | | | 0 g. | |
| 27 | .429 | .368 | .392 | | Northerly | | | 3 | | | 2 b.c.m. | |
| 28 | .390 | .323 | .355 | | N.N.W. | | | 3 | | | 6 b.c. | |
| 29 | .403 | .334 | .361 | | W.S.W. | | | 3 | | | 2 b.c.m. | |
| 30 | .370 | .293 | .333 | | S.E. by S. | | | 3 | | | 0 3 b.c. | |
| 31 | .290 | .092 | .189 | | S.E. | | | 6 | | | 3 b.c.q.p.r. | |
| | 30.438 | 28.441 | 29.4840 | | | | 4.63 | 4.63 | 4.63 | | | |
* For explanation of these symbols, see Appendix to Vol. I.
​ocean into space occasions the sea to be of a colder temperature as we advance to the south; and near the 70th degree of latitude, we find the line of mean temperature has descended to the depth of 750 fathoms; beneath which again, to the greatest depths, the temperature of 39°.5 obtains, whilst that of the surface is 30°.
This circle of mean temperature of the southern ocean is a standard point in nature, which, if determined with very great accuracy, would afford to philosophers of future ages the means of ascertaining if the globe we inhabit shall have undergone any change of temperature, and to what amount, during the interval.
The experiments which our limited time and means admitted of our making, serve to show that the mean temperature of the ocean at present is about 39°.5, or 7½ degrees above the freezing point of pure water; and as nearly as possible the point of its greatest density. But it would be indispensable that this temperature should be ascertained to the tenth part of a degree; and as we now know where we may send any number of thermometers down to the greatest fathomable depths, without an alteration of temperature, even to that small amount, this desideratum might be very easily obtained.
These observations force upon us the conclusion that the internal heat of the earth exercises no influence upon the temperature of the ocean, or we should not find any part in which it was equable ​from the surface to the great depth we have reached; a new and important fact in the physics of our globe.
On the following day thermometers were sent to March 28.the depth of 1200 fathoms, where the temperature was 39°.5; at 1050 fathoms, it was 39°.8; at 450 fathoms, 41°.1; at 300 fathoms, 44°; and at the surface, 53°. The specific gravity from 1050 fathoms, and 450 fathoms, was 1.0269 at 63°; that of the surface being 1.0275 at 53°. We were at this time in latitude 43° 10′ S., longitude 14° 44′ E.; the Cape of Good Hope bearing N.18 E., distant five hundred and fifty-six miles.
We had favourable winds and fine weather until the 4th of April, when, at 6$^h$ 20$^m$ a.m. the land was April 4.reported, and by noon we were close in with Cape Point. The wind blowing fresh, with frequent squalls, directly out of Simon's Bay, we had to beat up, and it was not until 7$^h$ 30$^m$ p.m. that we anchored close to her Majesty's Ship Winchester, bearing the flag of Rear Admiral the Honourable Josceline Percy, C.B.
Captain Crozier and I immediately waited upon the Commander-in-Chief, by whom we were received in the most kind and gratifying manner; and I had the satisfaction of reporting to him, for the information of the Lords Commissioners of the Admiralty, that the expedition had returned for a third time from the arduous service in which it had been engaged, without a single individual of either of the ships on the sick list.
​The refitment of the ships and refreshment of their crews, the repetition of our magnetic experiments, and comparison of our instruments with those of the permanent magnetic observatory, gave us full occupation to the end of the month. During the whole of this time we experienced not only every assistance in forwarding our operations, from the Commander-in-chief, but from himself, Mrs. Percy, and their family the greatest attention and kindness that consideration could suggest. We were also much indebted to Captain Eden, of the flag-ship, and Mr. Thomson, the store-keeper at the dockyard, for affording us every facility in their power.
April 30.At 8$^h$ 30$^m$ a.m. on the 30th we weighed, and, being quite calm, towed out of Simon's Bay. A breeze sprang up from the north-west at 10 a.m., and at noon we rounded Cape Point, and stood to the westward under all sail.
We had now turned our backs on the antarctic regions, and had fairly begun our homeward voyage, though we had one object yet to fulfil, which was, to go to Rio de Janeiro for magnetic purposes, touching, on our way, at St. Helena and Ascension.
We arrived at St. Helena on the morning of the May 13.13th, and found our old friend, Colonel Trelawney, of the Royal Artillery, now governor of the island. He welcomed us with that kind-hearted hospitality which was natural to him. We have since learned that his family and friends have to regret the loss of this excellent man.
​The comparison of our magnetic instruments 1843 was completed in a few days, and we sailed again, May 20.on the 20th, for the Island of Ascension, and without any events worthy of notice, arrived there on the 25th. Our magnetic experiments, before and after crossing the line of no dip, are of peculiar interest, and will be published with the rest of our magnetic observations, under the supervision of Colonel Sabine. In the Appendix to this volume will be found a table, containing our position at noon every day of the remainder of our voyage, the magnetic dip and variation, and the direction and strength of the current.
From Captain Dwyer, of the Royal Marines, May 29.commandant of the island, we received every attention and a supply of turtle for both ships, and we proceeded on our voyage at 9 a.m. of the 29th, steering for Rio de Janeiro.
We found the temperature of the air vary from 74° to 83°, and the surface of the sea from 75° to 77°, at this period of the season. The total absence of all sea-fowl is as remarkable here as in all other parts of the tropics we have visited, except only where small isles have been projected from the depths of the ocean, and afford them resting and breeding places.
On the 3rd of June, when in latitude 15° 3′ S., June 3.and longitude 23° 14′ W., being nearly calm and the water quite smooth, we tried for, but did not obtain, soundings with 4,600 fathoms of line, or ​27,600 feet. This is the greatest depth of the ocean that has yet been satisfactorily ascertained; but we have reason to believe there are many parts of it where it is still deeper. Its determination is another desideratum in terrestrial physics of great interest and importance.
The small island of Trinidad was at this time the nearest land to us; it bore S. 47 W., distant 486 miles. Cape Frio, the nearest part of the continent, bore S. 65 W., distant 1180 miles.
The temperature at twelve hundred fathoms was 39°.5; at nine hundred fathoms, 40°.3; that of the surface, 77°.
June 7.On the 7th we passed within a mile of Trinidad, but there was too much surf for us to attempt to land. On the 18th, at 4$^h$ 40$^m$ p.m., we anchored in the beautiful harbour of Rio. We regretted to find Commodore Purvis had gone to Monte Video, and, moreover, that all our letters had been forwarded to him there, contrary to his express orders. As we could not now get them in less than a month, and not choosing to lose so much time, I determined, as soon as we could complete our magnetic observations, to sail for England.
We found an American squadron lying here, under the command of Commodore Shubrick, upon whom Captain Crozier and I immediately called, and by whom, and his officers, we were most politely received. They had recently returned from Monte Video, the policy of their government not ​permitting them to take a part in the prompt and judicious measures adopted by Commodore Purvis and the commander of the French naval force.
From the British ambassador, Mr. Hamilton, we received every assistance in his power to accelerate our operations; which being completed by the 24th, we sailed at 8$^h$ 15$^m$ a.m. the following day, with a June 25light breeze from the northwest.
Commodore Shubrick sent all the boats of the American squadron to assist in towing us out of the harbour; but the breeze increasing steadily, rendered it unnecessary to avail ourselves of his kind attention.
Favoured by southerly winds, unusual at this season of the year, we made rapid progress over that portion of the passage which is often the most tedious, owing to the east and north-east winds which generally prevail; and, to-day, in latitude July 1.18° 23′ S. and longitude 31° 53′ W., we got the south-east trade wind.
On the 3rd, at 10 p.m. we crossed the line of no July 3.dip in latitude 13°.20′ S., and longitude 28°.ll′ W., where the trade wind being strong, with sharp squalls and rain, and with much sea running, prevented us making so many observations as we could have wished, and, therefore, the spot upon which we crossed it is not determined with equal precision as on our outward passage.
​The current, which at the equator averages a rate of more than twenty miles daily, carried us so far to the westward as to make us cross the line, at 8 p.m. of the 10th, in longitude 25° 54′ W.; and, in accordance with our observations on our outward voyage, the rate of the current in latitude 2° N. exceeded fifty miles per diem.
July 15.On the 15th we entered the variables and experienced the usual unpleasant weather; between 5$^h$ 30$^m$ and 6 a.m. an inch and a half of rain fell, and an inch and a quarter in the two following hours; its temperature was 72°, that of the air, 76°; and again, between noon and 2 p.m. on the 16th, 2½ inches of rain fell.
July 22.On the 22nd, when in latitude 12° 36′ N., and longitude 25° 35′ W., we had no soundings with 1850 fathoms, the temperature at that depth 39°.6; at 1350 fathoms, 39°.5; at 300 fathoms, 47°.6; at 150 fathoms, 52°; and at the surface, 79°.5. We were at this time only 140 miles from the Cape de Verd Islands.
Our barometrical experiments appear to prove that the atmospheric pressure is considerably less at the equator than near the tropics; and to the south of the tropic of Capricorn, where it is greatest, a gradual diminution occurs as the latitude is increased, as will be seen from the following table, derived from hourly observations of the height of the column of mercury, between the 20th of November, 1839, and the 31st of July, 1843.
​The mean pressure and the amount of atmospheric tide in each latitude are as follows:—
| Lat. | Pressure. | Tide. |
| At the Equator. | 29.974 | .047 | At sea. |
| 13°  0′ S. | 30.016 | .060 | {{{1}}}„ |
| 22 17 | 30.085 | .053 | {{{1}}}„ |
| 34 48 | 30.023 | .052 | Cape of Good Hope and Sidney. |
| 42 53 | 29.950 | .050 | Van Diemen's Land. |
| 45  0 | 29.664 | .031 | At sea. |
| 49  8 | 29.469 | .040 | Kerguelen and Auckland Islands. |
| 51 33 | 29.497 | .032 | Falkland Island. |
| 54 26 | 29.347 | .022 | At sea. |
| 55 52 | 29.360 | .027 | Cape Horn. |
| 60  0 | 29.114 | .024 | At sea. |
| 66  0 | 29.078 | .016 | {{{1}}}„ |
| 74  0 | 28.928 | .016 | {{{1}}}„ |
The above results are arranged in belts of latitude, the observations at sea being separated from those made in harbour; this occasions more apparent irregularity than would have been the case had they been formed into two distinct tables.
It has hitherto been considered that the mean pressure of the atmosphere at the level of the sea was nearly the same in all parts of the world, as no material difference occurs between the equator and the highest northern latitudes. At Melville Island in latitude 74¾° it was found to be 29.870, at Igloolik in latitude 69°, 29.770; and at Winter Island in latitude 66° 11′, 29.798. The cause of the atmospheric pressure being so very much less in the southern than in the northern hemisphere ​remains to be determined; and I trust that the very extensive series of observations made on board the Erebus and Terror will be of material assistance in the important inquiry.
Aug. 19.Early on the morning of the 19th, we saw the small island of Corvo, and at noon, when we were within a mile of the shore, two boats came off, loaded with eggs and fish, and fowls, all of which were very acceptable, and were procured without loss of time.
The shores of Old England came into view at Sept. 2.5$^h$ 20$^m$ a.m. on the 2nd of September, and we anchored off Folkstone at midnight of the 4th.
I landed early the next morning, and immediately proceeded to the Admiralty, where I met the most gratifying reception from Lord Haddington, Sir William Gage, and my highly valued friends, Admiral Beaufort and Sir John Barrow.
A few days after my arrival in London, I had not only the gratification of receiving the Founder's Medal awarded to me by the Council of the Royal Geographical Society of London, but that which afforded me, if possible, still greater pleasure, was the receipt of the Gold Medal of the Royal Geographical Society of Paris.
The ships proceeded to Woolwich, where they were dismantled and paid off on the 23rd of September; having been in commission rather more than four years and five months; and although they had gone through so much hard work, were as sound ​and ready for further service as on the day we sailed from England.
I cannot conclude the narrative of the voyage of the Erebus and Terror without expressing the high sense I entertain of the cordial and zealous support I invariably received from my excellent colleague, Captain Crozier, and the officers and crews of both ships, by whose unanimity, exertions, and skill, uninterrupted observations were made during the course of the expedition, which will elucidate several points of importance and interest in science, while they present others for examination, and afford a basis of comparison, should that sound mode of prosecuting inquiry be adopted. The geographical researches, moreover, will, I trust, be deemed to have contributed their share to the extension of our knowledge of the more remote southern regions of the earth.
Mount Haddington. Cape Gage.
* ↑ See Appendix, to Vol. II., p. 58.
* ↑ See Vol. I. p. 21.