52 



ANNUAL OF SCIENTIFIC DISCOVERY. 



tion, in numerous cases, did not exceed two or three years, and in no instance 

 of a rail-road having a heavy traffic, have the rails remained sound and in 

 working condition for more than 14 years. On some of the earliest constructed 

 lines in England, the rails have been changed twice, and even three tunes, 

 within, twenty years. Opportunities have, therefore, presented themselves to 

 the engineers of such lines, of ascertaining the actual traffic which iron rails 

 are capable of withstanding under different circumstances. 



The following table prepared by William Truran, Esq., and published in 

 the Canadian Journal of Science, shows the durability of different varieties of 

 railroad iron in thirteen carefully noted instances : 



EXPERIMENTS IN STOPPING RAILWAY TRAINS. 



Some experiments were recently made on the Brighton and South Eastern 

 Bail-way, England, by Capt. Tyler, for the purpose of ascertaining in how 

 short a period and distance a railway train could be stopped. Two trains 

 were made up, one by the Brighton Company, and the other by the South 

 Eastern, and laden respectively with about 32 tons of iron and other materials, 

 fairly distributed over the carriages, that being calculated to be about the 

 weight of 450 passengers. In order that these trials might have as much 

 similarity as possible to an ordinary case of driving a train, the men in charge 



