miles of sea-coast, including the circumnavigation of the bays and inlets, were visited to the eastward of the Coppermine River, and the latitude of 68° 18′ N. attained at Point Turn-again; but the whole of the plants collected during this part of the voyage were left behind, owing to the hardships encountered in the subsequent return across the barren grounds. This loss has been supplied, as far as regards the purpose of the present paper, by the collections made during Captain Parry's second voyage in the same parallels of latitude, and at no great distance to the eastward.

In making a few desultory remarks upon the circumstances which are likely to influence the vegetation of the districts, I shall begin with their altitude above the sea; and it is almost superfluous to remark, that we have few precise data on this subject, and must for the present be content with rude approximations. The line of country travelled through is destitute of lofty mountains, table-lands, or great plains; except that Carlton House may be said to stand on the northern boundary of a sandy plain, which, opening to the south, and extending to the confines of Mexico, is favourable to the migration of plants to the northward; but our stay in that quarter being confined to ten days at the commencement of spring, during which only thirty species of plants were gathered, few of these southern plants find a place in our list. Few hills were seen during the whole voyage, rising beyond 300 or 400 feet above the level of the surrounding country, and none exceeding 800, except on one part of the Coppermine River, where a range was observed to rise, on a rough estimation, to 1200 or 1500 feet; but even this was free from snow in the beginning of July. Indeed our route, being by the great rivers, and almost uninterrupted water communications of the districts, was

necessarily through the lower part of the country. Our barometer was rendered useless soon after leaving York Factory; so that I can only state in general terms, that, from the shores of Hudson's Bay to the Rocky Mountains, (a continuation of the Andes,) the ascent appears to be gentle, most rapid, however, about fifty miles from Hudson's Bay, where the rivers, in crossing a ridge of primitive mountains, form a quick succession of cascades and rapids.

Carlton House, the south-west limit of our journey, I estimate to be 1000 feet above the sea of Hudson's Bay. From this spot, our route to the north lay nearly parallel to the Rocky Moun tain chain.

The summit of Portage La Loche, or Methy Portage, which lies in 56° 43′ N. lat., and 109° 52′ W. long., and is about 250 miles from Carlton House, I estimated at 1500 feet. Methy Lake, the commencement on the south of this portage, of the water communication with Hudson's Bay, at 1000 feet, and Clearwater River, which flows from the north side of the Portage uninterruptedly to the Arctic Sea, under the names of Athabasca, Slave River and Lake, and Mackenzie's River, at 800 feet. Slave Lake at 400 feet above the Arctic Sea. The height of land to the north of Fort Enterprise, from whence the descent of the Coppermine River to the Arctic Sea, is gradual, at 900 feet. The data from which these altitudes have been deduced are not precise enough to be worthy of detail; but the results, imperfect as they are, may be sufficient to show that the elevation alone of these districts is not great enough to give a decided character to their vegetation.

The peculiarities of the Hudson's Bay climate, which have a more marked influence on the vegetable productions, may be, in some measure, col lected from the following tables, and

e remarks appended to them. The bles are formed on the model of those ven by Humboldt, and the deeply in resting memoir of that illustrious man the Distribution of Heat, published the Mémoires d'Arcueil, or its transtion in the 3d, 4th, and 5th volumes

of the Edinburgh Philosophical Journal, may be referred to, for the original views which prompted the formation of such tables, and the many interesting deductions that may be made from them.

Table I.

ance has been made in the table at the rate of 1°.8 of temperature for each degree of latitude, by which the place of observation exceeded 54°; and the same addition was made to the recorded temperatures for June, July, and August 1820; during which months we travelled 10m Cumberland House to lat 64° N. The allowance of 1°.8 here used is greater than that which Humboldt specifies for the same parallel of latitude; but it was obtained from a comparison of the mean annual tem

peratures of Cumberland House and Fort Enterprise, which are 10 degrees of latitude apart. The observations for the other months in the Cumberland House column, were made within the stockade of the fort, and a deduction of 1° has been made from each recorded observation, to compensate for the radiation from the neighbouring buildings-an allowance which corre'sponded with the few observations we made upon the subject. The means for some of the months were deduced from three or more observations each day, taking into account the length of the intervals. In the rest of the months, the means of the extremes have been used, which differ only in a fraction of a degree from the more correct mode of taking the intervals into account.

The temperatures in the column for lat. 64° were (except those for the latter end of June, the month of July, and the beginning of August) taken at Fort Enterprise, in a shaded situation, on a northerly exposure, and not subject to any material radiation from warm buildings; and an addition of 0°.5 has been made to the registered temperatures, as a reduction to lat. 64°; Fort Enterprise being actually 28 miles north of that latitude. The temperatures for July, and the early part of August, in this column, having been observed during the journey from the parallel of 55°, an allowance of from 10.5 to 1°.8 has been deducted for each degree of latitude, according to the situations of the places of observation. The temperatures for June, after the 10th, were

taken in lat. 65°, and have therefore been corrected for lat. 64° by an addition of 1°.5 Fahr.

With regard to the temperatures in the three remaining columns, Captain Parry observes, "that the thermometer, when placed on the shore, or on the ice, at a distance from the ship, invariably stood from 3° to 4° or 5°, and on some occasions 7° lower than the temperature registered on board;" and he in consequence deducts 3° from the mean temperature for the year. In the above table, an attempt has been made to proportion the compensation for the warm atmosphere of the ships, amongst the months, so that the greater allowance is made when the difference of temperature between the atmosphere and ship was greatest, or, in other words, in the coldest months. Thus, in July and August, when the radiation of the earth is supposed to be nearly equal to that of the ship, the registered temperatures are used without alteration. the other months, a deduction has been made, increasing from 2° to 5°, as their mean temperatures decreased. The annual means thus obtained are nearly the same with Captain Parry's corrected temperatures; but the differences betwixt the summers and winters a little exceed those given by his tables.

In

The means were obtained by Captain Parry from the twelve daily observations, made at intervals of two hours, or from 4380 observations in the year, and thus possess a degree of accuracy which is very rarely attained.