462 THE APPLICATIONS OF PHYSICAL FORCES. [BOOK iv. 



English engineer, Blackett (1813), proved that the adherence of the 

 locomotive to the rails could be secured. To this period belongs 

 "Puffing Billy" (Plate XVI.), in which the axle-trees were kept 

 working together by means of an endless chain. The adherence of 

 all the wheels of the locomotive was thus secured. 



The " Puffing Billy," the oldest locomotive engine in existence, 

 and the first which ran with a smooth wheel on a smooth rail, was 

 constructed in 1813 by Jonathan Foster, under William Hedley's 

 patent, for Christopher Blackett, Esq., the proprietor of the Wylam 

 Collieries near Newcastle-upon-Tyne. This engine, after many trials 

 and alterations, commenced regular working in 1813, and with tender 

 and two trucks, a total load amounting to fifty tons, ran at an average 

 rate of six miles an hour. It was kept at work until the 6th 

 June, 1862, and was then purchased for the Patent Museum. 



It may be said that from this moment locomotion on iron rails by 

 means of carriages moved by steam was a problem practically solved. 

 Nevertheless, the locomotive did not as yet give a satisfactory 

 result; the quantity of steam that the boiler could furnish was 

 insufficient for the work or the Velocity that was to be obtained. 

 The reason of this lay in the nature of the boiler, the water in 

 which was heated by a fire within a tube which traversed its whole 

 length. The heating surface was not large enough for the vaporization 

 required, and the draught was altogether insufficient. 



In the years 1814 to 1820, thanks to the combination of George 

 Stephenson, William James, and Edward Pease, the importance of 

 improving the locomotive was clearly seen. Stephenson was em- 

 ployed on the Killingworth Eailway in 1814, and often saw "Puffing- 

 Billy " at work. An Act of Parliament was obtained for a passenger 

 railway between Stockton and Darlington in 1821, and James en- 

 deavoured, without success, to establish a railway between Liverpool 

 and Manchester in 1822. By 1829 the locomotive had arrived at 

 the form shown in Eig. 313, which represents the locomotive engine 

 " Rocket," constructed by Stephenson, to compete with other engines 

 on the Liverpool and Manchester Railway, where it gained the prize 

 of 500. The Liverpool and Manchester Eailway was formally 

 opened for passenger traffic on the loth September, 1830. 



The locomotives of Stephenson and Hackworth in many respects 

 realized improvements which had their importance. The driving 



