Transportation on Land 



291 



These early engines are the beginnings of the development 

 of a kind of locomotion which has completely revolutionized 

 travel and transportation. The engines produced by George 

 and Robert Stephenson, especially the type in which the power 

 of the piston is directly transmitted to the driving wheels 

 (Fig. 91), anticipated the most recent and powerful creations. 



FIG. 91. Stephenson's engine "Billy No. 1" patented 1815. Direct 

 transmission of power to the driving wheels. The engine weighed 16,600 

 pounds, and the tender 8600. It could haul 50 tons at five miles per hour, or 

 70 tons at lower rate of speed. Compare with power transmission of the 

 "Stourbridge Lion," showing advantages. 



The modern locomotives easily surpass the earlier types in 

 power, speed, facility of control, and efficiency; but they are 

 constructed in accordance with the principles of steam locomo- 

 tion which were worked out a hundred years ago. 



125. The modern locomotive. As an example of what 

 modern locomotive engineering is producing, we may refer to 

 the present most powerful and largest engine in the world, a 

 three-engine or triplex type, built in the Baldwin locomotive 

 works for the Erie Railroad (Fig. 92). 



