Page:Maury's New Elements of Geography, 1907.djvu/35

Rh it up as far as you can. Then trace a line directly north to the shores of the Arctic ocean. You will thus move your finger through the central part of the continent. In it there are some low mountains and many hills and valleys, but because of its generally smooth surface this region is called the Great Central plain.

Along the shores of the Atlantic ocean and the Gulf of Mexico is a Coastal plain, which extends back to the foothills of the mountains. Along the Pacific coast the mountains often come down to the ocean, but in some places there is a narrow plain called the Pacific plain.

5. Rivers.—If you trace along the tops of the mountain ranges shown on page 35, you will find that many rivers begin there. The ranges are the great divides, or watersheds, of the continent and cause the water to flow in opposite directions. You will find also that many rivers flow through valleys, which they have cut out for themselves through the mountains. Others flow through the Great Central plain and have many branches. Near the center of the continent you find rivers flowing north and south. This means that there is high ground there which forms a watershed, dividing the Great Central plain into a northern and a southern slope. The southern slope is drained by the Mississippi river and its branches, which form the chief river system of the continent. The northern slope is drained by rivers which flow into Hudson bay and the Arctic ocean. Between the highland region and the coast are many short rivers.

The rivers of the plain are very useful for carrying the products of the country to the sea, where they may be sent in ships to foreign countries. Many of the shorter rivers have swift currents and are not navigable. 6. Lakes.—Find the St. Lawrence river and follow up its course until you come to a large lake. This is one of five lakes which are known as the Great Lakes. They are the largest bodies of fresh water in the world. Thousands of ships sail on them, carrying the products of the country. Northwest of the Great lakes are many others extending in a sort of chain nearly to the Arctic ocean.



1. Divisions.—North America is divided into several parts, or countries. Our own country, the United States, is in the middle.

If we travel northward from the United States, we enter the Dominion of Canada. If we go northeast from Canada, we come to icy Greenland and Iceland (Danish America). If we go northwest from Canada, we come to Alaska which belongs to the United States.