PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 353 



of employes, but that it eludes the eye and can only be completely met by 

 automatic apparatus. 



The arrang-ement of the parts of this i-egulator is calculated to convey 

 as little heat as possible to the leather diaphrag^m; and results presented to 

 3"our committee of leather, said to have been somewhat similarly exposed 

 in twelve months' use, g'ive promise of durability. They have no further 

 guide on this point, or on the possibility of exactly uniform production; 

 but they suggest that, by careful mechanical construction, the principle of 

 these reg-ulators may be rendered effective at lower pressure. 



The objects to be tested were arranged in committee, viz: the range of 

 regulation, the advantage of quasi-packing- at different pressures, and the 

 ordinary'' waste with unperceived "blowing'." The experiments themselves 

 were made by one of your committee only; they are, therefore, presented 

 only on the authority of its chairman, but your committee unanimously 

 concur in the opinions deduced from them. 



Your committee are much indebted to the courtesy and liberality with 

 which the Manhattan Gas company placed their valuable apparatus at its 

 disposal during several hours. 



(Signed) John Hartley Churchill, 



Charles A. Seely, 



July 10, 1862. John Johnson. 



[Am. Inst.] '^3 



