CHAP. VII f. STEAM ON COMMON KOADS. 137 



These views, thus early entertained, originated in 

 Mr. Stephenson's mind the peculiar character of rail- 

 road works as distinguished from all other roads ; for 

 in railroads, he early contended that large sums woulc 

 be wisely expended in perforating barriers of hills with 

 long tunnels, and in raising the lower levels with the 

 excess cut down from the adjacent high ground. In 

 proportion as these views forced themselves upon his 

 mind and were corroborated by his daily experience, he 

 became more and more convinced of the hopelessness o 

 applying steam locomotion to common roads ; for every 

 argument in favour of a level railway was, in his view 

 an argument against the rough and hilly course of 

 common road. 



At this day it is difficult to understand how the 

 sagacious and strong common-sense views of Stephenson 

 on this subject failed to force themselves sooner upon 

 the minds of those who were persisting in their vain 

 though ingenious attempts to apply locomotive power 

 to ordinary roads. For a long time they continued to 

 hold with obstinate perseverance to the belief that foi^ 

 steam purposes a soft road was better than a hard one 

 a road easily crushed better than one incapable of being 

 crushed ; and they held to this after it had been de- 

 monstrated in all parts of the mining districts, that iron 

 tramways were better than paved roads. But the 

 fallacy that iron was incapable of adhesion upon iron 

 continued to prevail, and the projectors of steam- 

 travelling on common roads only shared in the common 

 belief. They still considered that roughness of surface 

 was essential to produce " bite," especially in surmount- 

 ing acclivities ; the truth being, that they confounded 

 roughness of surface with tenacity of surface and contact 

 of parts ; not perceiving that a yielding surface which 

 would adapt itself to the tread of the wheel, could never 

 become an unyielding surface to form a fulcrum for its 

 progression. 



