The New Student's Reference Work/Aqueduct
Aqueduct (ăk' wē-dŭct), a channel for carrying water, or a structure on which water-pipes are laid. This method of carrying water has been in use from the earliest times. Persia, Judæa and many other eastern countries practiced it; while the Incas or rulers of Peru in the western world built aqueducts which have not been equaled in ancient or modern times. The Romans built these works all over their dominions. Rome was supplied by 24 aqueducts, some with several channels, one above another, extending many miles. They are built on a grade of regular descent, winding around the hills or piercing them by tunnels and supported across low levels by arches sometimes over a hundred feet high. Many cities are now supplied with water by this means. The Croton aqueduct, from the Croton river to New York city, is one of the greatest of modern aqueducts. Its construction cost $12,500,000, and five years were spent in building it. Its length is 40½ miles, and there are 16 tunnels, cut mostly through the solid rock. An idea of the magnificence of this undertaking may be gained from the fact that the Harlem River is crossed by fifteen arches, seven of which are of 50 feet span, while eight are of 80 feet, the greatest height being 150 feet.
Other important aqueducts are those used for carrying canals across rivers and valleys. The chief examples in the United States are those on the Erie canal, 32 in number. At Pittsburg the Pennsylvania canal is carried across the Allegheny River upon a wire suspension aqueduct. Among the latest works of this kind is the new Croton aqueduct in New York, which cost over $20,000,000.