Proceedings of the Polytechnic Association. 1059 



direction would soon accomplish tlie desired end. The defects of 

 this apparatus would show where the improvements are to he made. 

 He commended this apparatus as ingenious, and hoped the inventor 

 would perfect it. 



Dr. J. J. Edwards thought that at the present high rates of labor 

 on indoor work, almost any machine would pay if it could be made 

 to operate satisfactorily. 



Adjourned. 



April 16, 1869. 



Dr. D. D. PARsrELEE, in the chair; Mr. C. E. Emery, Secretary. 



Dr. Parmelee stated that Professor Tilhnan was detained at 

 Albany on business connected with the Institute, and, at hio-request, 

 he, the doctor, occupied the chair. He would open the proceedings 

 by requesting an exhibition of new inventions. 



Yentilatoe and Air Filter. 



Mr. Converse exhibited a model of the ventilator invented by Mr. 

 Lesperance, of Canada, which is intended to be used for filtering the 

 air which is admitted to buildings, railroad cars and passenger ves- 

 sels. The air is caused to pass through three plates of perforated 

 tin, a covering of sponge and a box filled with charcoal, and the 

 inventor claims that any superfluous dampness will be retained in 

 the sponge, in the first chamber, while all impure gases will be 

 absorbed by the charcoal in the second chamber. " The air is ren- 

 dered warm, first, by the amount of friction it has to undergo ; sec- 

 ondly, by being deprived of. its watery vapor, and thirdly, by the 

 chambers through which it passes being warmed by the heat of the 

 room." 



The reader will understand that this description is taken from the 

 pamphlet published by the inventor. 



Dr. Bradley asked what power was employed for the purpose of 

 forcing the air into the room, and also inquired what number of ven- 

 tilators would be required for an ordinary sized apartment. The 

 reply was, that onp ventilator of ordinary size would provide an 

 amount of air sufficient for twelve persons. 



The exhibitor explained that the ventilator was not intended to 

 provide for the exit of the foul air; that it was to be supposed that 



