A CRUCIAL TEST. 81 



different attempts to remedy it, including what we may term 

 an elaborate system introduced no later than three years 

 since, the room in which the City Fathers hold their 

 conclaves was one of the worst-ventilated apartments for its 

 size, as a public one, in the metropolis. Smarting under the 

 annoyances they had long laboured under, the City Archi- 

 tect was finally instructed by the Corporation to request 

 Mr. Boyle to submit a system of ventilation adapted to the 

 requirements of the chamber, but on the conditions that it 

 would only be accepted after exhaustive trials had proved to 

 the City Architect an4 a committee that it was successful ; and 

 if not to their satisfaction, every vestige of it was to be 

 removed within a specified time, and everything made good, 

 at Mr. Boyle's expense. 



Thus the contract was entered upon on the principle of 

 "no cure, no pay." Confident in his system, Mr. Boyle 

 accepted the terms, and the guarantee, which was of a very 

 stringent character, was drawn up by the Corporation, and 

 was of such a nature as would put the system to a most 

 severe and crucial test. At the tests that were made after the 

 completion of the work we need only mention that the 

 average quantity of vitiated air withdrawn amounted to 

 500,000 cubic feet per hour, and that during the whole of 

 the experiments, official and otherwise, not the slightest 



down-draught was experienced ; had it been otherwise the 



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