The inland canal and lake system of Canada, together with the United States Canals at the Sault St. Marie, have established an unbroken water communication, for vessels up to 1800 and 2000 tons (gross), from Duluth, at the western extremity of Lake Superior, to the Straits of Belle Isle, at the mouth of the St. Lawrence river—a distance of 2384 miles.
The difference in level between Lake Superior and the St. Lawrence, at Montreal, is about 600 feet, and fifty-five locks are required to overcome this, although the mileage of the eight canals is but seventy-one. The ordinary locks of the Canadian canals are 270 feet long, by 45 feet broad, and 14 feet on the sills, and the American locks at the Sault, as already mentioned, are 515 feet long, 80 feet wide, and 18 feet on the sills. These locks are all built specially wide, to accommodate the various classes of steamers and barges employed; for it has been remarked that although in England the trade is arranged to suit the boats, in America the boats must be built to suit the trade, and the locks accordingly.
┌───────┬─────────────────────────────┐ │ │ Bushels of Grain carried by │ │ Year. ├────────────┬────────────────┤ │ │ Railway. │ Canal. │ ├───────┼────────────┼────────────────┤ │ 1885 │ 10,007,061 │ 6,559,000 │ │ 1886 │ 6,685,000 │ 11,366,000 │ └───────┴────────────┴────────────────┘
[122] The leading particulars as to the location and characteristics of this canal are given at p. 209, and need not here be repeated.
THE WATERWAYS OF SOUTH AND CENTRAL AMERICA.
“Whole rivers here forsake the fields below, And, wondering at their height, through airy channels flow.” —_Addison._
_The Amazon._—Of the many navigable highways in South and Central America, the Amazon river is by far the most important. Nay, more, this river, which has a drainage area of 2,264,000 square miles, which has 10,000 miles of navigation for large boats, and which has a width of no less than four miles at a distance of 1000 miles from the sea, is in every respect the most extensive and remarkable river in the world.
The average depth of the Amazon river is 42 feet in the upper portion, and 312 feet near to its mouth. The influence of the tide is observable at a distance of 400 miles from the mouth of the river, the usual current of which is about three miles per hour. The flood rise is from 42 to 48 feet above the lowest level. At a distance of 3000 miles from its mouth the Amazon is only 210 feet above sea level. Reclus has estimated the average discharge of the river to be 2,458,026 cubic feet per second.[123]