Remarks on Railway and Marine Signals. 129 



employed are nearly useless, perhaps even mischievous as 

 leading to a false sense of security. 



Without contending that all the requirements are 

 thoroughly worked out, I am convinced that the systematic 

 testing recommended by the International Medical Congress 

 of last year (and copies of the " resolutions" have no doubt 

 before now been widely distributed over the civilised world) 

 would, if carried out as directed, at once reduce to a small 

 fraction the dangers to travellers through mistakes from 

 visual defects of officials on steamships and railways. 



