PROCEEDINGS 



OF THE 



ROYAL SOCIETY OF EDINBURGH. 



1832-33. No. 2. 



April 1. 



Sir THOMAS MAKDOUGALL BRISBANE, K.C.B., 

 President, in the Chair. 



The following Donations were presented : — 

 Annual Report of the Yorkshire Philosophical Society for 1832. 



— From the Society. 

 Collections of Specimens from the Volcanic District of the Rhine. 



— From Professor Forbes. 



The following Communications were then read : — 

 1 Continuation of " Experimental Researches regarding 



certain vibrations which take place between Metallic 



Masses having different Temperatures." By James D. 



Forbes, Esq., Professor of Natural Philosophy in the 



University of Edinburgh. 

 The vibrations here referred to, are those which, with their accom- 

 pany in<r sounds, were fust observed by Mr Arthur Trevelyan, and 

 communicated to this Society in a paper published in the 12th vol. 

 of their Transactions. The author of the present paper undertook 

 the inquiry as soon as the remarkable fact was announced by Mi- 

 Trevelyan, and was induced to prosecute it to a considerable extent 

 experimentally, in consequence of being dissatisfied with the oidy 

 plausible explanation yet offered.— that of the successive expansions 

 of the cold metal by the hot one at the point of contact at each sue- 



