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een miles) as to lead to the conclusion that Foxe must have been m possession of Baffin's chart, which Purchas found too troublesome and expensive to engravé. All the other charts that we have seen are very far wide of the truth.
In the second place, the swinging of the pendulum on Hare Island in lat. 700 26' has given results, we understand, highly satisfactory, as tending to corroborate the previous theory for determining the precise figure of the earth, built on experiments made in various latitudes, but never before in one so high as this.
In the third place, the variation and dip of the magnetic needle, and the intensity of the magnetic force taken at different places so very near to one of the magnetic poles, are, in themselves, exceedingly curious, and may lead to important conclusions. It had been foreseen that the probable approach of the ships to one of the magnetic poles would afford the opportunity of making some interesting observations, and accordingly compasses of various construction, and other instruments, were provided for this purpose. We cannot find, however, that they have been used to the extent which would be desirable.
Another phenomenon, connected with these observations, seems, however, to have attracted the marked and continued attention of our navigators. It had been noticed, on Captain Cook's voyages, that the variation of the magnetic needle differed very sensibly on the same spot with the different directions of the ship’s head, but not to such extent as to be considered of much importance to navigation. Captain Flinders, however, resumed the subject, and made a series of observations both on his voyage of discovery, and after his return to England, from the result of which he constructed a formula for correcting the error of the ship’s course as steered by the compass. This formula, however, was found to be wholly inapplicable in high latitudes, where the deviation of the needle from the correct variation was much more considerable than where Captain Flinders had an opportunity of making his observations. He concluded, justly enough, that the error was occasioned by the iron in the ship; but conceived that the attractive power of it was concentrated in some particular part of the ship, whose influence was exerted on that pole of the needle which dipped towards the pole of the earth, and was drawn aside towards it. The fact, however, as might have been supposed, is, that the compasses of different ships are differently affected, according to the quantity and the disposition of the iron einployed
in the construction of the vessel, or of her ballast, guns, &c. and it consequently, that each ship will have her particular deviation,
VOL. XXI. NO. XLI.
which will differ very materially in different parts; and the points of one ship's head, which give no deviation, will
, probably, in another, be those of the greatest deviation. These irregularities must, no doubt, be owing to the unequal distribution of the iron with regard to the two sides of the ship. This was remarkably the case on the present occasion, the compasses of the Isabella differing from those of the Alexander not merely several degrees, but in some situations several points; in fact, in the high latitudes where the dip and variation were greatest
, so sluggishly did the needles act, that those which were loaded with heavy cards would scarcely move at all, but stood still at any point to which they were directed. In middle and low latitudes this deviation is of little or no importance, and in high latitudes we suspect it can only be truly ascertained by actual observations frequently repeated. Dr. Young, however, has constructed a formula and a table from the experiments of the Isabella, which may assist, at least, in coming to an approximation of the deviation. The following results of the mean of several observations taken on the ice, for determining the variation and dip of the magnetic needle, may be considered as approaching nearly to the truth.
20 26 izl54 55 55 82 g 39 41 42 45 Three islands of Baffin. 174 1 20/57 55 45 84 915 81 37 19 West coast of Greenland. 74 57 45 59 49 30
87 19 341 Do.
175 29 60 42 43 84 25 6 87 43 11 Do. 75 49 62 43 451
90 43 22 Do.
175 51 30/62 40 84 44 55 Do. 75 50 164 48 57
91 2 12 Head of Baffin's Bay. 75 54 21 65 56
92 1 Do.
76 32 173 45 85 44 38 Do. 176 33 577 952
107 3 57 Do.
76 8 2878 35 38 85 59 31109 35 58 West coast of Davis's Strait. 73 30 177 24 9
109 32 53 taken on sbore. Do.
170 36 -67 27 45/84 39.351 86 14 44 A series of observations on the temperature of the sea at the surface, and at certain depths, may serve to correct erroneous notions, which, it would appear, have prevailed on this subject. We have no doubt they are the most accurate that have yet been made, and in deeper water than a self-registering thermometer had ever been sent down before in any part of the world. The result is very different from that of former observations. It seems that, in Baffin's Bay, the temperature, generally speaking, decreases with the depth. At 1005 fathoms, in lat. 71° 24', the temperature was 81°,
at the surface 36%, and whenever the depth exceeded 100 fathoms, the thermometer generally descended to 30°, or below, when 34 ör 35 at the surface. Near Cape Walsingham, it is stated that, from the depth of 660 fathoms the thermometer came up at 256; from 400, at 28°; from 200), at 29°; and from 100, at 30°: the temperature of the air being 37°. It would be difficult to explain why the sea remained in the state of water at 25° of Fahrenheit
. Did the pressure of the column of water prevent its freezing ?-or was the water more strongly impregnated with salt? These and other observations made in the course of this voyage, both on land and sea, are completely at variance with the theory of isothermal lines of temperature which had been assumed, as it would now appear, from a too limited number of facts. But the most unaccountable circumstance is that of the Polar Expedition having, in the seas of Spitzbergen, on the same parallels of latitude, invariably obtained a contrary result, the temperature of the sea increasing with the depth; so that when the thermometer at the surface stood at 32° or 330, at 300 fathoms it was 360 or 37'. We pretend not to explain this singular anomaly ; indeed we do not conceive that we are yet in possession of a sufficient number of facts to enable us to reason on the subject.
A remarkable uniformity of temperature prevailed throughout the three months the ships were within the Arctic circle. During the whole of this time, the mercury in Fahrenheit's thermometer (in the shade) never ascended beyond 53°, nor fell below 261°; and these extremes occurred but once, the general average being between 350 and 37o. The consequence of which, and of keeping the ship dry, was, that no deaths took place, and scarcely a day's illness in either vessel; and Mr. Parry, judging from these circumstances, says, “I have not the smallest doubt that a ship provided, as we were, with abundance of provisions, warm clothing and fuel, might winter in the highest latitude that we have been in, without suffering materially, either from cold or disease. When we reflect on the wintering of William Barentz and his companions in 76° of latitude in the coldest country on the face of the earth, destitute of all these advantages, we can scarcely doubt that Mr. Parry is right.
So long as the sun was perpetually above the horizon, there could not be any appearance of the aurora borealis. This phenomenon commenced, however, with the commencement of night, and was frequent' on the return voyage. In a tremendous gale off Cape Farewell, these lights played with awful magnificence. The Isabella was furnished with an electrical apparatus, contrived by Sir Humphry Davy, but it does not appear to have been used. Mr. Parry paid particular attention to the compasses duR 2
ring the appearance of the aurora, but could not perceive that it had the slightest influence on the magnetical needle, either in altering its direction or causing any tremulous motion; he observed however that the arc was generally, though not invariably, intersected by the magnetic meridian.
Where nature has been so sparing in the number and variety of her gifts, much could not be expected from the expedition, especially as no professed naturalist was employed on the occasion: the few opportunities which occurred for collecting specimens were not, however, neglected. On this subject, Captain Ross complains of the unwillingness of Captain Sabine to assist him, which he certainly ought to have done, though not engaged specifically for that purpose. It is a great misfortune for the interests of science, that commanders of ships of war and naturalists rarely agree; but it arises generally from the objects of their several pursuits interfering with each other. Captain Cook indeed agreed with every one; but Vancouver and Menzies quarrelled. Boudin was at variance with all the savans on board; but this was the less to be wondered at, as they were almost numerous enough to man the ship: and Captain Freycinet, who is now employed in the southern hemisphere in astronomical, magnetical, and meteorological observations, positively refused to take on board a single naturalist.*
We observe with pleasure that in consequence of the Prince Regent's Order in Council, grounded on the late amended Act of Parliament, the Board of Longitude has adopted a graduated scale of rewards for discovery, proportioned to the progress made to the westward, from Hudson's or Baffin's Bays towards the Pacific Ocean: as certain portions of these rewards are allotted to places not very remote from the usual haunts of whale fishers, such as have not been fortunate in the fishery may be induced to strive for them, through Cumberland or Lancaster's Straits, or some other of the numerous openings in the western land. It is possible in. deed that the first point of the scale, the meridian of the Copper Mine River of Hearne, (which entitles to 5,0001.) may turn out to be much nearer to Davis's Strait than it appears to be on the charts. Mr. Hearne, by his own account, made but one single observation for the latitude, and that at a considerable distance from the mouth of the river, so that whether its latitude be 69° or
* To be even with the Captain, the Minister of Marine interdicted all females fronı proceeding on the voyage, knowing that Freycinet had intended to take his wife with him. Ou the third day after the ship's departure from Toulon, a youth made his appearance on the quarter-deck whom the con mander bad not before observed—it was his wife, who, in the disguise of a seaman, had got on board just as the ship was weighing anchor, and concealed herself among the crew.
72° is left undecided. But this is not the most material part of his omissions : whether he had a compass with him or not, we cannot tell; but at all events, we conclude that he laid down his track without any regard to the variation; and for this reason,—that, having left a spot on the margin of Hudson's Bay, over which the magnetic meridian, or line of no variation, passed, a person so evidently inattentive to the latitude and longitude of a portion of the continent never before trodden by an European foot, can scarcely be supposed to have given any consideration to the variation of the magnetic needle, which was known to have none or very little at the spot from which he started. Now we know from Mackenzie's observations, that, at Fort Chepawyan, situated in about 58° of latitude, and on or near the meridian of Hearne's river, the variation of the needle in the year 1789 was 14° east, and at the mouth of Mackenzie's river in latitude 69° it was 36° east. As the mouth of Hearne's river, even as now laid down, cannot be half the distance from the magnetic pole that Mackenzie's river is, and as we may conclude, from the very extraordinary increase of variation in proceeding northward up Baffin's Bay, that a similar increase, in a contrary direction, would take place in proceeding northward from Fort Chepawyan, we may further conclude that the course of the Copper Mine river is not north, as laid down in Hearne's chart, but deflected to the eastward of that point; and will perhaps be found to open either into the Welcome or Davis's Strait, which would be the case if we allow only four or five points of easterly variation, though we cannot doubt, from its nearness to the magnetic pole, of there being much more. Hearne, in his narrative, talks vaguely of the sea being full of islands and shoals at the mouth of the river, as far as he could see with the assistance of a good pocket telescope; but in his introduction, which was written many years after the journey, he observes, " I think it is more than probable that the Copper river empties itself into a sort of inland sea, or extensive bay, somewhat like that of Hudson's. There is another circumstance corrobora, tive of our supposed direction and termination of the Copper Mine river. We noticed in our review of Captain Burney's Memoir on the Geography of the North-eastern part of Asia,'* the observation of the late Mr. Dalrymple, that, on one of the vative Indian maps, painted on skins, the sea is continued from Hudson's Bay to the Copper Mine river, and that in this circumstance all the Indian maps
reports concur. Mr. Barrow says that a chart of this kind is still in the Hudson's Bay Company's House; that the Jets from the bay are marked on it with tolerable accuracy; and * that the coast is carried northerly without interruption the
* No. XXXVI.