S/A' ll'/LL/AM SIEMENS, J-'.N.S. 203 



the paper, p. 147 ; Mr. Thomson had the honour of laying this 

 formula before the Institution some years ago, when Mr. Kirk's 

 paper mi the Mechanical Production of Cold was read and 

 discussed. At that time Dr. Siemens mentioned that the formula 

 was due to Clausius, but Mr. Thomson had deduced it from 

 Rankine's works. 



Dr. Siemens observed that Clausius and Rankine worked 

 independently and simultaneously at the same question, and 

 arrived at the same conclusion. He did not doubt the correct- 

 ness of the formula put forward by those eminent mathematicians 

 find physicists, but he doubted its applicability under all con- 

 ceivable circumstances to the question under consideration. 



In the discussion of the Paper 



"ON THE THEORY OF THE GAS-ENGINE," 

 By DUGALD CLERK, 



DR. SIEMENS * said that one part of the paper dealt with 

 matters regarding the mechanical arrangement of gas-engines, and 

 the other with a theoretical question, that of the law of com- 

 bustion. He would refer to the theoretical part first, because 

 the author appeared to attach great importance to it, and as 

 Dr. Siemens had from time to time given a great amount of con- 

 sideration to the action of negative combustion or dissociation, 

 it might be of some interest to the members to see how far his 

 views fell in with those set forth by the author. It was well 

 known that by combustion no unlimited degree of temperature 

 could be attained. Thus, in a furnace worked at very high tem- 

 perature the fuel was not completely burned when it came in 

 contact with the oxygen of the heated or non-heated air. The 

 moment a certain comparatively high temperature was reached 



* Excerpt Minutes of Proceedings of the Institution of Civil Engineers, Vol. 

 LXIX. Session 1881-82, pp. 251-4. 



