fairly compressible, so that if miles of ice are piled on them a 

 great basin may gradually be formed on the surface of the earth. 



When, however, this load of ice is removed, the "basin" thus 

 formed first fills with water — salt, if a channel to an ocean is 

 available, or otherwise with fresh. But then, the land as a whole 

 begins slowly to rise again, and the water begins to flow out of 

 the basin (as it is doing to the sea from Hudson Bay today). 

 However, if there is no ready outlet it just floods o' er the sur- 

 rounding land and forms numerous lakes until they find new 

 overflow points as have the Great Lakes. Only ancient blocks of 

 non-sedimentary rocks that have their roots deep in the sub- 

 surface layer of the earth — like the northern Rockies and the 

 Laurentian Shield in Quebec— do not sag appreciably under a 

 temporary load of ice. 



All across the great plateau and lowlands of the north central 

 part of this continent there are the most profound evidences of 

 glaciation. These include drumlins. rounded, elongated, oval hills 

 of ice-borne debris up to about a mile wide, and from 100 to 

 200 feet high; eskers, or narrow, dykelike sand or gravel ridges, 

 from about 25 to 100 feet high, which may be as much as fifty 

 miles long, and sometimes appear to be perfectly straight; and 

 fossil beaches, low ridges of sand which often run parallel to 

 coasts and to each other and sometimes mount to some hundred 

 feet in height. Hudson Bay is completely ringed by all these and 

 by numerous other evidences of the presence of an icecap and 

 of the movements of vast depths of ice outward from a common 

 center. 



What has been happening in this area is that, since the ice 

 last melted away or "retreated" northward, the land has been 

 springing back; Hudson Bay has been draining off into the Davis 

 Strait, and the Great Lakes have been struggling to get out 

 through the St. Lawrence valley, and thus cutting back the 

 Niagara Falls at a startling rate. However, a great deal of sur- 

 face water has become temporarily caught in the countless 

 millions of little lakes and ponds all around the Hudson Bay 

 basin itself and all the way to the Mackenzie. This has resulted 

 in a country unlike anything seen anywhere else in the world. 

 It is clothed in solid stands of somber spruce trees interspersed 

 with muskeg all across its northern belt. South of this the spruce 

 is increasingly interlarded with, first, isolated aspen and then 

 groups of them; then white birch and other hardwoods come in. 

 and this eventually merges with the deciduous forest belt, which 

 stretches right across the continent from sea level in British 

 Columbia to and around the Great Lakes and thence to the 

 St. Lawrence valley and New England. 



Here, one stage removed from the Arctic, the seasons are 

 considerably different. The black night of winter is not quite so 

 long; the day-round painted dawns of spring and the sunsets of 

 winter go on longer; the spring is a little earlier and more color- 

 ful; the summer is longer and more riotous; the fall is much 

 longer and absolutely breath-taking in its magnificence. In 

 winter this whole province is covered with deep snow from 

 which the spiky spruce heads emerge like discarded Christmas 

 trees. The snows begin in October; the break-up of the ice on the 

 Mackenzie River does not come till mid-May, so that for a full 

 seven months the greater part of this province is, as it were, sub- 

 merged. Once the snow melts, the land burgeons miraculously; 

 mammals, birds, and insects appear in their multitudes, flowers 

 bloom, and the trees put out shoots with a rush. Although there 

 is actually a long spring from a climatic point of view, there is 

 virtually none from the visual. One day the winter is still 

 rotting; the next, and especially if the sun shines, it is early 

 summer, with the aspens a delicate bluish green and a sort of 

 chartreuse fuzz all over the spruce. 



As in all the sub-Arctic provinces, the summers are very hot 

 and dry. The ground is covered with a thick carpet of sphagnum 

 and other mosses with lichens and fungi and small lush herbs 

 both on the muskeg and under the trees, and this always retains 

 water like a sponge. In the north it rests upon permafrost which 

 does not thaw during the summer. Farther south it acts some- 

 what unexpectedly, in an exactly contrary manner, insulating 

 the subsoil from the winter cold by freezing solid and preventing 

 deep penetration of frost. The results are surprising. If the land 

 is cleared — as in modern road construction — and the few feet 

 of black soil under the muskeg and the forest is scraped off, the 

 land dries out completely in summer, resulting in choking dusts 

 that range from fairly coarse-grained sand to stuff so fine that 

 it penetrates anything not hermetically sealed. The dust of the 

 sub-Arctic is worse than anything blown up by any hot desert, 

 and in those areas where the subsurface of the whole land is 

 formed of clay, as around the southern end of Hudson Bay, it 

 has the cloying quality, the consistency and permeability, of a 

 rubber-based paint. 



GOLDEN WATERS 



Although this province is said to lie on the western curve of the 

 great Canadian Shield from a geological point of view, it has 

 little if any similarity to the eastern curve of the Laurentians and 

 Labrador. Apart from the great clay belt south of Hudson Bay, 

 the whole land surface is covered with a few feet of black, peaty 

 soil, lying on comparatively recent — geologically speaking — 

 glacial deposits composed of gravels, sands, and clays. These in 

 turn are spread over sedimentary rather than the ancient 

 plutonic rocks so typical of the Laurentians and the east. The 

 great rivers that flow northward across this territory drop down 

 from the central continental plateau in steps, meandering along 

 for some hundred miles, then suddenly discharging into gorges 

 cut deep into the apparently level surface, and wandering along 

 again until the whole land has fallen the equivalent of another 

 step. Then the rivers drop into another canyon, the walls of 

 which gradually diminish. The most beautiful and interesting of 

 these gorges may be seen about thirty miles south of Great Slave 

 Lake, and is now named the Alexandra Falls. There, the Hay 

 River drops over a 110-foot fall into a gorge cut back into the 

 vast plateau that slopes down to the sealike lake. 



The water of this river is clear but is the color of dark 

 sherry, and when it pours over a hundred-foot cliff in the vivid 

 northern sunlight it becomes a vast half-dome of glutinous 

 amber. The rocks of the gorges lie exactly horizontal and are 

 formed of countless thin beds of hard-compacted, flintlike 

 limestone, each bed being about two to three inches thick. They 

 have been eroded off above the falls in such a way that the river 

 passes between huge platforms composed of sheets of rock that 

 look for all the world like the leaves of an opened book. These 

 rock faces are full of fossils. 



Even in winter this country has a smooth, austere beauty, and 

 in summer it is exquisitely mellow. For two or three weeks at 

 the end of September it blazes with colors that are unbelievably 

 vivid and outrageously contrasted. The river valleys that cut into 

 the apparently level plateau also present unforgettable spectacles 

 in fall. Their bottoms and the lower ends of the side creeks that 



The so-called Arctic Fox, a small foxlike dog of the tundra, 

 preys mostly on lemmings and may store them in caches for 

 the following winter. 



42 



