All About Engines

The Locomotive 255 Surface. He went to see experiments of this kind at Wylam and at Leeds, and then succeeded in per- suading Lord Ravensworth, the owner of the Killing- worth pit, to advance money for the attempt. His first engine was completed in 1814 and suc- ceeded in drawing a load of 30 tons on a rising gradient of 10 feet a mile, at a speed of four miles per hour ; but he found that it was no cheaper than using horses. A second engine, containing several im- provements, was built in the following year. It had vertical cylinders fixed in the top of the boiler, and the cranks were operated by long connecting rods on each side. The front and rear axles were con- nected by a chain working on sprockets or toothed wheels, which fitted the links. The most curious contrivance was the use of pistons working in cylinders in the lower part of the boiler to support the axle boxes and to serve the purpose of springs. But the main improvements lay in the jet through which exhaust steam escaped into the chimney, thus in- creasing the draught and doubling the power of the engine. The engines built in 1816 were still more effec- tive, and some of them remained in use for many years. About the same time better methods of tracklaying and of jointing the rails were intro- duced. The amount of success gained was an incen- tive to further study, and Stephenson began to make experiments on the relation between the weight of the train and the force required to draw it—the draw-bar pull, so called because a spring balance is