No. L] 



GEOGNOSTICAL OBSERVATIONS. 



499 



The surrounding country, and the banks of the river as far as the junction of 

 the Sharnattawa, fifty miles from the sea, has a low uniform swampy appear- 

 ance. Immediately under a thin stratum of half-decayed mosses, there is a 

 thick bed of tenacious and somewhat slaty bluish clay, containing many 

 boulder stones. As the stream is continually encroaching upon some points, 

 and depositing its spoils on others, its banks are alternately steep and shelv- 

 ing, but the bed of the river is in general from thirty to forty feet below the 

 level of the adjoining ground. The soil nourishes a pretty thick forest, but 

 the trees, consisting chiefly of spruces, larches, and poplars *, are small ex- 

 cept in very favourable situations. Slips of the banks are frequent, and the 

 trees either retain their erect position or lie in various directions athwart the 

 stream, and seem to thrive in both conditions until cut down by the ice in the 

 spring floods. It is worthy of remark that the sub-soil is perpetually frozen. 

 This retains the surface water, and converts the country into a swamp in which 

 sphagna and other mosses grow, but owing to the shortness of summer they 

 decay very slowly, and little peat is formed. The surface is still hard 

 when the smaller plants, under the powerful influence of an almost midsum- 

 mer sun, begin to flower ; and by the middle of September, when the heat has 

 penetrated the farthest into the earth, the leaves are falling. In a favourable 

 summer the ground is thawed to the depth of four feet, but there still remains 

 a frozen bed, whose thickness we had not an opportunity of ascertaining by 

 personal observation, although we were informed by the residents that it ex- 

 ceeds eleven feet, and that underneath there is loose sand. 



We did not observe the ground permanently frozen any where in the inte- 

 rior ; and its occurrence at York Factory ought, perhaps, to be attributed to 

 the vicinity of the sea. A frozen ocean can contribute nothing towards tem- 

 pering the severity of winter, but the ice which hangs upon these shores gene- 

 rally to the middle of August, must have a powerful effect in diminishing the 

 summer heat ; hence the warmest summers on the American continent, between 

 the 55 and 65 parallels of north latitude, are to be looked for at the greatest 

 distance from the sea : accordingly we find that vegetation is much more active 

 even on the elevated range of the Rocky Mountains than it is on the same 

 parallel on the shore of Hudson's Bay. The same rule does not apply to 

 both sides of the American continent, for, to the westward of the Rocky 



* Pinus alba, nigra et microcarpa; Populus trepidant balsamifera. 



