41 6 THE SCIENTIFIC PAPERS OF 



particularly of modern improvements, would say that iron would 

 soon be a past manufacture," said he was hardly bold enough to 

 make such an assertion ; at the same time he believed that steel 

 was on the whole preferable for the new application. While 

 continental nations had been giving great attention to the intro- 

 duction of metal permanent way, England had remained perhaps 

 too partial to timber as the material to be employed. It was true 

 that English engineers would now have the advantage of the 

 experience already gained, and when turning their minds to the 

 subject they would soon perceive not only the advantage of the 

 metal system, but the most practical mode of carrying it into 

 effect. Iron should be strong enough for the purpose, because 

 each portion of an iron cross-sleeper was apparently not strained 

 beyond its capability of resistance ; still he apprehended that 

 homogeneity was of great importance, because where the fastening 

 held, the metal was strained to a very considerable extent an 

 extent which could hardly be determined ct, priori, and in all such 

 cases steel yielded before it fractured under compressive strains. 

 Then again, he believed that the introduction of steel sleepers 

 would be of great advantage to the manufacturer, even though he 

 should not realize large profits from the actual operation. It was 

 well known that in Germany, where iron and steel sleepers had 

 been largely introduced, the manufacturer was glad to supply them 

 at a comparatively low cost, because he could go on with the 

 manufacture without waiting for specifications. It was always 

 the same thing, and whenever he had no other work on hand he 

 -could turn to rolling sleepers ; moreover, although a good metal 

 should be employed, it was not necessary to use entire ingots, but 

 considering the short length of a sleeper, odds and ends of the 

 material could be utilized to a considerable extent. Therefore he 

 had no doubt that, for the two reasons he had mentioned, the 

 comparatively low price at which sleepers could be supplied, and 

 their great permanency when once laid down, iron or rather steel 

 permanent way would soon be very largely, if not universally, 

 introduced into this country. 



