﻿442 Prof. Swan on a Metallic Connector to replace 



I cannot end without sincerely thanking the learned author 

 for the honour which he has bestowed on me by condescend- 

 ing to criticise my ' Elements of Molecular Mechanics/ The 

 more so, as his criticism, whilst impugning a few points of 

 secondary importance, contains what to my great satisfaction 

 I consider to be a virtual approbation of my leading princi- 

 ples. Nothing can be more gratifying to the author of a scien- 

 tific work than to find his fundamental views shared by men 

 of such accomplishments in science as Professor Norton is 

 known to be, whatever unavoidable differences may remain in 

 some matters of detail. 



LXI. On a Metallic Connector to replace the Vulcanite Tube used 

 with Bianchi's Air-pump. By William Swan, LL.D., 

 F.R.S.E, fyc, P?*ofessor of Natural Philosophy in the Univer- 

 sity of St. Andrews*. 



IN the air-pumps constructed by M. Barthelemi Bianchi of 

 Paris, which are driven with a continuous motion of rotation, 

 the cylinder C (fig. 1), like that of an oscillating steam-engine, 

 vibrates on trunnions, T, U, through a considerable arc. The 

 trunnion T is pierced to form an air-passage, to which a tube (A) 



* Communicated by the Author, having been read before the Literary 

 and Philosophical Society of St, Andrews, April 17, 1869. 



