in 1. 1. 1 AM SIKMENSi F.K.S. 139 



its condensation ; and a veil composed of the non-condensible and 

 non-conducting portion of the mixed gases would thus remain to 

 protect the rest of the steam in the cylinder from contact with the 

 cool metal surfaces, and would thereby prevent further loss from 

 condensation. He believed this was a point of considerable im- 

 portance in favour of the use of the combined steam and air in an 

 t-n^ine with unprotected cylinders. The application of the same 

 plan to a condensing engine was one that he had not been acquainted 

 with previously ; and from the statements which had been given 

 it appeared that the introduction of so large a quantity of air with 

 the steam had not been found to prevent the formation of a 

 tolerable vacuum. 



The use of the air injection was a subject which he hoped would 

 be more fully investigated ; and from the perseverance which had 

 been shown in working it out thus far there was reason to expect 

 the plan would be developed to a still further extent. He moved a 

 vote of thanks to Mr. Eaton and Mr. Warsop for the paper, which 

 \\as passed. 



In the discussion of the Paper 



" OX A SIMPLE CONSTRUCTION OF STEAM-ENGINE 



GOVERNOR HAVING A CLOSE APPROXIMATION 



TO PERFECT ACTION," by Mr. JEREMIAH HEAD, 



MR. C. W. SIEMENS * remarked there could be no doubt that 

 by the plan of crossing the suspending arms of the governor, so as 

 to cause the balls to expand in a parabolic curve within certain 

 limits, as described in the paper, a real chronometric action was ob- 

 tained ; but such an action would not be practically applicable to 

 regulate the speed of a steam-engine, because, as had been ex- 



* Excerpt Minutes of Proceedings of the Institution of Mechanical Engineers, 

 1871, p. 226. 



