PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 495 



Mr. Garvey said that by making the wheel shaped, any amount 

 of adhesion could be attained, as is proved by the frictional 

 gearing in common use in England. Some time since he devised 

 the plan of making the rims of driving wheels shaped for this 

 purpose. 



Mr. Seely suggested as a subject for discussion at the next 

 meeting: "The recent practical applications of magnetism." 



Adjourned until Thursday evening, October 18, 1860, at 7^ 

 p. M. 



Subject for discussion : " Recent practical applications of mag- 

 netism." 



American Institute, Polytechnic Association, ^ 

 October 18, 1860. \ 



Prof. Mason in the chair. 



The Chairman inquired whether there was any miscellaneous 

 matter which any member wished to bring forward. He would 

 listen to anything that might be said in reference to the subject 

 which was postponed for two weeks, namely : " The use of steam 

 by expansion." 



Mr. Dibben made some remarks on the subject, and, in answer 

 to an inquiry made by Mr. Fisher, stated that his remarks were 

 founded on theory. He stated that Mr. Joule has said, in one of 

 his works on the subject, that for every particle of heat he could 

 give so much power, and vice versa. 



Mr. Rowell. — The simple fact of expansion was the force. 



Mr. Hedrick was of the opinion that if you put on heat 

 enough to bring it up to the same heat that was used when it 

 began to expand you would have Marriott's law. 



Mr. Seely. — If we talk about this subject we will continue to 

 talk about Marriott's law. Marriott's law says that the tempera- 

 ture after condensation is the same as before. 



The Chairman. — Do you mean to say that Marriott did not 

 comprehend the subject that he was dealing with ? 



Mr. Seeley. — Yes, I believe so. I think it is very clear that 

 sixty pounds of steam would not expand to double its size and 

 give you a volume of heat at the same time. 



The Chairman said that he was unable to bring the gentleman 

 to the meeting who was making the experiments on the New 

 Jersey Central railroad. He stated that he was authorized by 



