All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

2i4 All About Inventions conceived the idea of placing small cups around the periphery of a wheel mounted upon the shaft, instead of blades. The idea was found to be prac- ticable, and the Pelton wheel soon sprang into favour. Development followed development rapidly, the great- est measure of attention being devoted to the design of the cups in order to utilise the force of the impinging water to the utmost. Other inventors adhered to the vane or blade system, virtually adapting the steam turbine principle to water-power, thereby producing a strict water turbine. Both methods have a considerable vogue, and many impressive installations have been brought into operation. The Falls of Niagara have been harnessed, a moiety of the tremendous aggregate energy—estimated to be 7,000,000 horse-power—there running to waste being harnessed to generate current for lighting, heating, and power for miles around. Waterfalls have been tamed in various other countries __even in these islands—for a similar purpose. Fac- tories, railways, and tramways run on current derived in this manner; while miles of streets and scores of thousands of buildings are lighted by electricity which has been obtained by taming a wild waterfall or swiftly rushing stream or river. One of the largest hydro-electric stations which has been brought into operation during recent times is that at Keokuk, in the Mississippi Valley. A huge barrage, 4,278 feet in length, has been thrown across the full width of the Father of American rivers, and near one bank there is a huge power house, 1,718 feet in length by 132 feet in width, housing thirty hydro- electric units, each having a capacity of 7,500 kilo-