The surface of the country east of the great lakes is diversified, but characterised by no outstanding features. Two ranges of hills skirt the St. Lawrence--that on the north, the Laurentians, stretching 3,500 miles from Lake Superior to the Atlantic, while the southern range culminates in the bold capes and cliffs of Gaspe. The St. Lawrence and its tributaries form the dominating physical feature in this section, the other rivers being the St. John, the Miramichi, and the Restigouche in New Brunswick. Eastern Canada is practically the Canadian part of the St. Lawrence valley, (330,000 square miles), and the great physical feature is the system of lakes with an area of 90,000 square miles. In addition to the tributaries of the St. Lawrence already mentioned, the Dominion boasts the Fraser, the Thompson, and the greater part of the Columbia River in British Columbia; the Athabasca and Peace Rivers, which flow into Lake Athabasca, and out of it as the Slave River, which in its turn issues from the Great Slave Lake and flows into the Arctic Ocean as the Mackenzie River (total length 2,800 miles); the Albany and the Churchill, flowing into Hudson Bay, and the Nelson, which discharges from Lake Winnipeg into Hudson Bay the united waters of the Assiniboine, the Saskatchewan, the Red River and the Winnipeg. West of the Great Lakes the scenery is less varied. From the lakes to the Rockies stretches a vast level plain of a prairie character, slowly rising from 800 feet at the east end to 3,000 feet at the foothills of the Rockies. The eastern and western portions of the Dominion are heavily wooded, and comparatively little inroad has been made on the forest wealth of the country. It is estimated that there are 1,200,000 square miles of woodland and forest, chiefly spruce and pine, including about a hundred varieties; consequently the industries connected with the forest are of great importance, especially since the development of the pulp industry. The central prairie plain is almost devoid of forest. Agriculture is the dominant industry in Canada, not only in the great fertile plains of the centre, but also on the lands which have been cleared of forest and settled in other parts of the Dominion. The Canadian climate is cold in winter and warm in summer, but healthy all the year round. With all its extremes of cold it permits of the cultivation in the open air of grapes, peaches, tobacco, tomatoes, and corn. The snow is an essential condition of the prosperity of the timber industry, the means of transport in winter, the protector of the soil from frost, and the source of endless enjoyment in outdoor sports.