TRAVELLING ABROAD IN PURSUIT OP KNOWLEDGE. 69 



which, however, his genius has always been successful in 

 defying. Mr. Robert Boyle, jun., has visited nearly every 

 civilized country in the world for the purpose of studying 

 the different systems of ventilation in use, and ascertaining 

 if they satisfactorily fulfilled the requirements which the 

 climate of each country demanded. In the pursuit of these 

 studies he naturally gained a vast amount of information 

 respecting existing sanitary appliances, and from actual 

 experience of them was enabled to discover their defects. 

 These his inherent inventive powers enabled him to rectify, 

 the result being the long list of valuable sanitary improve- 

 ments with which his name is identified, and which have 

 made him conspicuous as a sanitarian and as one of the 

 most prolific inventors of the present day. Among the best 

 known of his inventions may be mentioned the double-action 

 system of soil-pipe ventilation, which utilizes the natural 

 motion of the atmosphere so as to exert a double power 

 in the soil pipe. With this system the air is admitted as 

 well as extracted above the roof. There being no air inlet 

 at the ground level it is impossible for |x>isonous gases to 

 escape excepting at the top of the pipe. This system has 

 now been thoroughly tested, having been subjected to very 

 severe trials, and is pronounced by the most competent 

 authorities to be the best and safest system of soil-pipe 

 ventilation which has yet been brought out. Its chief merit 



