Engineering Wonders of the World
Volume III

276 ENGINEERING WONDERS OF THE WORLD. is drawn towards the socket by screw bolts passing through it and a second collar (B), embracing the splayed portion of the socket. This collar is tapered on the inside to the same angle as the socket. The tighten- ing up of the bolts forces the packing into place, and also presses down the socket on B SECTION THROUGH A “ MUFF ” JOINT IN USE ON THE PIPE LINE. to the packing by virtue of the wedging action of B. This type of joint permits every pipe to expand and contract longitudinally without causing leakage, and renders it possible to insert a new packing while a pipe is under full working pressure. The water turbines in the power-house were made by Escher, Wyss, and Co. of Zurich, and are of the well-known high- Pelton Wheels. _ , . , pressure Pelton wheel type, with spoon-shaped buckets set in pairs round the circumference of the wheels. A good idea of the rotating part of a turbine, with, buckets shaped somewhat differ- ently, is afforded by the photograph which is reproduced by permission of the Pelton Wheel Company of San Francisco. Nine of the wheels have an over-all diameter of 8 feet, and an output of 3,200 horse-power each ; two are 6 feet in diameter, and develop 930 horse- power each. The water strikes the very sharp edge of the wall between a pair of buckets, and is deflected right and left round the inside of the buckets, losing practically all its velocity. The inner surface of the buckets is polished so highly that 98 per A PELTON WHEEL. (Photo, The Pelton Wheel Company.) cent, of the water’s energy is transmitted to the buckets. INSTANTANEOUS PHOTOGRAPH OB1 WATER ISSUING FROM A NOZZLE AGAINST A PELTON WHEEL. (Photo, The Pelton Wheel Company ) The water is projected as a solid bar from a specially shaped nozzle of very hard steel carefully polished inside. The supply of water is regulated by means of a concentric tapered needle, the movements of which, effected by