Proceedings of the Royal Irish Academy. 



the triangle. Each side of the triangle is a mas. of maxima for half the span, 

 bernc the radius of a semicircle. Each super-max. occins when a wheel is 

 over a point, which was the end of the base of the triangle as it turned over ; 

 that is, at a point Tialf as far from the centre of the span as the wheel is from 

 the centre of gravity of the locomotive. 



V y 



—1 = 21: , 





Fig. 4. 



But the stress diagram thus generated by the triangle SiDS, applies to 

 another manner of loading : to a uniform dead load numerically dovile the 



