Turbine

a wheel designed to utilize the force of falling water or of a current of steam or air for mechanical purposes. The water turbine differs from the ordinary water wheel. The water wheel turns like a roller, its axis horizontal; the turbine whirls like a top, its axis vertical. The details of the turbine construction are too technical for description here. The turbine is set to form the bottom of a tube or well which is filled with water from above. The weight of the water column, at bursting pressure, causes the water to escape through the turbine and turn the wheel as it goes. There are different types of turbines. In one, the jets of escaping water drive the buckets of the turbine by reaction. When one jumps from a skiff toward the shore he gives the boat a send in the opposite direction. The reaction turbine turns in the opposite direction from the flow. In the second type or impulse turbine, the buckets are carried with the escaping jets and the turbine turns with the flow. Still a third turbine is turned by a combination of impulse and reaction.

The turbine does not require a water fall of great height. A large, slow wheel may be operated with a head, or fall, of even a foot. A water turbine in the Black Forest of Germany is cited as having a diameter of thirteen inches and driven by a water column 354 feet high. In 1905 powerful turbines were installed at Niagara Falls. Ten turbines are driven by water delivered by ten steel tubes or penstocks seven and one-half feet in diameter and 136 feet high. Each turbine is fitted to a vertical steel shaft that weighs 150,000 pounds. The pressure of the water to escape is so great that these seventy-five-ton shafts are buoyed up till there is virtually no friction in the bearings in which the lower ends of these monstrous vertical axes are pivoted.

Steam turbines have been known ever since the day of Hero the Alexandrian. During the latter half of the nineteenth century, the steam turbine was developed. In 1894 it was applied successfully to the navigation of ships. The steam, escaping through nozzles, acts on the curved vanes of the turbine, producing a powerful circular rotation. As compared with the steam engine, with its cylinder, valve, and piston, the steam turbine requires less space, is lighter, is less likely to get out of repair, is safer, costs less to install, weighs less, does more work, works more rapidly, requires less fuel and less attention, runs with less jar, and does not need as heavy shafting or as large a propeller. Turbine liners began to cross the Atlantic in 1905.