198 Modern Business Geography River. The tendency of the barge canal and its branches is to cheapen transportation from New York City to the Great Lakes and Canada. The St. Mary’s Canals, commonly called the “Soo”! Canals, allow ships to pass from Lake Superior to Lake Huron around St. Mary’s Falls, which drop twenty feet in three fourths of a mile. A canal with one lock, built by Canada, lies north of the falls, while south of them are two American canals with four locks. The tonnage of freight passing through these canals is enormous. Each year nearly a hundred million tons of freight pass through the three canals. This is four times the tonnage passing through the Suez Canal and almost equals that handled by New York City. The value, however, is much less than at Suez or New York, for the merchandise consists prin- cipally of iron ore, lumber, and coal — bulky goods of low value. How the canals vary in their purposes. Canals have various pur- poses. Some, like the Soo Canals, are cut to avoid rapids or falls. The Welland Canal in Canada between Lake Erie and Lake Ontario, avoiding Niagara Falls, is another example of this type. Other canals shorten long or dangerous voyages. For example, the Suez Canal, which permits Europe to trade with the Orient and Australia without sending ships around the Cape of Good Hope, is a great carrier of the commerce of the oceans. The Kiel Canal, connecting the Baltic Sea with the North Sea, avoids the long route around the peninsula of Denmark. The Cape Cod Canal across the base of Cape Cod, Massachusetts, allows ships to save one hundred miles and avoid a dangerous part of the route between New York and Boston. Still other canals allow inland cities to become seaports. The Man- chester Ship Canal, in western England, permits ocean steamships to carry cotton thirty-five miles inland to Manchester. Another good illustration is in Texas, where Houston is trying to get part of Gal- veston’s cotton shipping business. Houston has the advantage of being a railroad center and of lying nearer the cotton fields than does Galveston (Fig. 5). By building a canal and a “basin” in the level plain it gains also some of the advantages of being a seaport. The Panama Canal The difficulties of building the canal. To many persons the most interesting of the world’s artificial waterways is the Panama Canal. [t was built by the United States at a cost of $400,000,000 and was the largest single piece of engineering ever undertaken by any govern- { From the French name for the passage between the lakes — the Sault Ste. Marie.