All About Engines

256 All About Engines introduced between the engine and the train. He found that a force of about io lb. per ton weight was required, and as a gradient of i in 100 decreased the weight capable of being hauled by about 50 per cent., he became convinced of the necessity of making the track as level as possible. Before Stephenson’s time interest had been centred mainly upon the use of steam for propelling car- riages upon ordinary roads, but when the import- ance of smoothness and level had been so clearly demonstrated the importance of the latter was over- shadowed for many years. It is not, however, within the scope and purpose of this book to deal with the development of the railway, and we must now examine in greater detail the development of the locomotive as a steam engine. Stephenson further established his reputation in 1822 by using locomotives on the level portion of the Hetton Colliery track, near Sunderland; and in 1823 he built the Stockton and Darlington Rail- way and ran upon it the “ Locomotion,” an engine of his own construction. This engine was quite successful, but after the opening ceremony horses were employed for passenger traffic. (See Fig. 142 on Plate 25.) Appointed engineer to the Liverpool and Man- chester Railway, he succeeded in persuading the directors to give the steam locomotive a trial, and a prize of £500 was offered for the best engine. There were four entries—the “ Novelty,” the “ Sanspareil,” the “ Perseverance,” and Stephenson’s “ Rocket,”