Engineering Wonders of the World
Volume III

174 ENGINEERING WONDERS OF THE WORLD. the the are A taining immense pumps attached to a nozzle composed of a series of knife-like blades, places this nozzle on the spot to be exca- vated ; the blades revolve, and the earth is drawn into a vast suction-pipe. A single dredge will move 168,000 cubic yards of earth in twenty-four hours. The phases of development on Drainage Canal interesting studies, water-power plant at Lockport will have five units of 8,000 horse- power ; and a large amount of water-power is now being developed at the south end of the canal, where it dis- charges through a tail- race into the Des Plaines River. The controlling in- terests of the canal have been steadily ac- quiring from time to time strips of land from 200 to 800 feet in width, with a view to use in connection with manufacturing plants that will be installed to utilize the water- power to be developed, and to take advantage of the shipping facilities afforded, by the canal. The Illinois and Michigan Canal proper, of which the above described canal is only a unit, is 91 miles in length, with an additional 18 miles in the Illinois River. Its width averages 80 feet at water-line, and its depth is 7 feet. In all there are about thirty-four locks. Twenty have mitre gates throughout, and fourteen have lower gates of future water-power THE WOODEN NEEDLES OF A NEEDLE DAM, AND TRESTLE. The Illinois and Michigan Canal. the mitre type, the upper, or “ tumble,” gates turning on a horizontal axis. Hydraulic pressure is used to lower the upper gates, which lift themselves by their own buoyancy. The locks are 35 feet wide and 170 feet long between mitre sills, and are built of concrete. Proceeding down the Mississippi we reach cotton, lumber, fruit, and mineral districts. At the delta of this great river is found the interesting Lake Borgne Canal, in the State of Louisiana. It is 7 miles long, 200 feet wide, and very deep. Since 1901 it has given continuous water communication with three southern lakes (the Maurepas, Pontchartrain, Borgne) and southern rivers (the Mobile, Alabama, and Warrior). It has re- duced distances great- ly. Gulf of Mexico traffic is brought right up to the mouth of the Mississippi River, to the levees at New Orleans, Louisiana. Expensive transhipment has been abolished and freight - rates reduced. Sea-going vessels, drawing 10 and 12 feet, can come within 20 miles of New Orleans without the cost of towage. This canal has also changed the status of coal in New Orleans. Prior to its construc- tion, coal was a luxury, as it had to be floated 2,100 miles down the Mississippi River from Pennsylvania ; but now Lake Borgne Canal has opened up the coalfields in the sister States of Mississippi and Alabama, reducing prices of and three