What may be called the Arctic climate extends over nearly the whole of Danish America, the newly-acquired possessions of the United States, the original Hudson Bay Territory, and Labrador, down to that unimportant watershed which separates from the tributaries of Hudson Bay the three great basins of the St. Lawrence, the five great lakes, and the Mississippi. This line of watershed undulates between the 52nd and 49th parallels of latitude, from Belle Isle Strait to the sources of the Saskatchewan, in the Rocky Mountains, where it inflects towards the Pacific Ocean, skirting on the north the basin of the Columbia. Thus bounded on the south, the Arctic lands of America, including the groups of islands lying to the north and north-east, cannot occupy less than 560,000 square leagues. They exceed, therefore, the superficial area of the European lands, estimated at about 490,000 square leagues. We propose to divide these lands into two zones or regions, the wooded and the desert zones: the former, in America, includes the basins of the Upper Mackenzie, the Churchill, the Nelson, and the Severn. In the wooded zone the thermometer does not rise above zero until the month of May. Then, under the influence of a more genial temperature, the breath of life passes into the slumbering, inert vegetation. Then the reddish shoots of the willows, the poplars, and the birches hang out their long cottony catkins; a pleasant greenness spreads over copse and thicket; the dandelion, the burdock, and the saxifrages lift their heads in the shelter of the rocks; the sweet-brier fills the air with fragrance, and the gooseberry and the strawberry are put forth by a kindly nature; while the valleys bloom and the hill-sides are glad with the beauty of the thuja, the larch, and the pine. The boundary between the wooded zone and the barren would be shown by a line drawn from the mouth of the Churchill in Hudson Bay to Mount St. Elias on the Pacific coast, traversing the southern shores of the Bear and the Slave Lakes. To the north, this barren zone touches on eternal snow, and includes the ice-bound coasts of the Parry Archipelago; to the east and the north-east, identity of climate and uniform character of soil bring within it the greatest part of Labrador and all Greenland. In Asia the isothermal line of O° descends towards the 55th parallel of latitude, one lower than in America,--though to the north of it some important towns are situated, as Tobolsk, lat. 58° 11’; Irkutsk, lat, 58° 16’; and Yakutsk, lat. 62°.