Canal

an artificial waterway. Mill races, sluiceways, and irrigation canals are also designed to convey water. As generally used, however, the term canal is applied to waterways permitting the passage of boats and ships. Canals are of great antiquity. The Grand Canal of China is more than 800 miles long. In the prosperous days of Babylonia, Mesopotamia was intersected by waterways. Lower Egypt was well provided with canals. The Romans constructed canals from the lower Rhone to the Mediterranean, and from the Tiber to the sea. The plains of Lombardy were connected with the Adriatic Sea. A canal from the Bay of Biscay to the Mediterranean was completed in 1681. It is 148 miles long. It saves a far-about voyage of 2,000 miles through the Straits of Gibraltar. Holland, Belgium, portions of France, England and northern Germany are covered by networks of artificial waterways. A system of canals connects St. Petersburg with the Caspian Sea. A canal 108 miles long, by way of the Main, connects the Danube and the Rhine.

The first boat canal in the United States was built in 1793 around the Falls of the Connecticut River at South Hadley. There are now about forty inland canals in the United States with an aggregate length of over 2,470 miles. They have cost $200,000,000. They lie chiefly in New York, Virginia, and intermediate territory. One of importance, 196 miles in length, runs from Chicago to La Salle at the head of navigation on the Illinois River. The Ohio Falls Canal is constructed around the rapids of the Ohio River at Louisville. It is only 11,000 feet long, but is of great importance to navigation. The most celebrated canal in the United States is the Erie, connecting Buffalo on Lake Erie with the Hudson River at Albany, a distance of 352 miles. It was opened in 1825. Its first cost was $7,602,000. The cost of freighting was reduced, however, from $100 a ton to $3.

Canada has built three important canals for the improvement of the St. Lawrence and Great Lakes waterway. The Sault Ste. Marie Canal permits passage through the rapids between Lakes Superior and Huron; the Welland Canal enables ships to pass the Falls of Niagara; a third passes around the Lachine Rapids in the St. Lawrence River.

Of ship canals the Suez Canal is the most celebrated. It unites the waters of the Mediterranean with the Red Sea. The Caledonian Canal connects the Firth of Forth and Loch Eil. The Manchester Canal connects that city with Liverpool. The Kaiser Wilhelm Canal connects the North Sea with the Baltic.

While digging a ditch through the ground seems very simple, the construction of a canal is really an engineering work of great difficulty. It requires to be carried over waterways on aqueducts. The Erie Canal crosses the Mohawk River on arches twice. The Suez Canal is level from end to end. In case, however, that a canal of this sort would require too deep a ditch in the middle of its course, it must be constructed in sections at different levels, connected by locks. In its simplest form a lock is a water-tight passageway, or a basin fitted with doors at the upper and lower ends. When a boat desires to descend into a lower part of the canal, it enters the basin and the upper doors are closed behind it. The water is then allowed to run out of the basin until the boat has dropped to the level of the section below. The lower doors are then opened and the boat passes on its way. In case it is desired to raise the boat to a higher level, it enters the basin from below, the doors are closed behind it, and water is admitted from above until the basin fills, raising the boat to the level of the upper section. The upper doors are then opened and the boat proceeds on its way. Sometimes a number of locks are built at the same place. In this way a boat is enabled to climb a hill--one step at a time.

Sometimes canal boats are pulled up an inclined plane by steam power. What are known as tank elevators are used in the canals between Belgium and Paris. Peterborough, Canada, has one of the largest canal locks of this sort in the world. It consists of two water-tight steel boxes, each holding 1,300 tons of water. These ascend and descend by hydraulic power, between three great guide towers, 100 feet high, built of solid masonry. When one box is up, the other is always down. A boat enters a box; the gates close; a little additional water is introduced into the other box, and the boat rises swiftly and steadily to the higher level. The operation is almost automatic, three minutes being required to make the lift. The entire lockage is accomplished in twelve minutes. This lock was completed in 1903 at a cost of $500,000.

The Erie Canal has seventy-two locks. Fifty-seven of them are double. Boats are lifted at West Troy 188 1/2 feet, and at Lockport 54 1/2 feet. The total difference in the level of the highest and the lowest section of the canal is 568 feet. The locks of the Morris Canal in New Jersey lift boats 1,084 feet. Canals require to be wide enough so that boats going in opposite directions may pass each other. In ship canals the ship is usually towed by a tug. In boat canals it is pulled by means of a towrope and horses or mules driven on shore along a towpath constructed for the purpose. A rudder serves to prevent the boat from running ashore. The canal men live usually with their tow animals in the boat. Many families have no other home.

See Erie Canal; Suez Canal; Panama Canal; Corinth; Sault Ste. Marie; Paris; Lock; Nova Scotia

American Canals.

Showing the cost, date of construction, length, and navigable depth of the principal commercial canals of the United States and Canada.