THE GAMGEE- PERPETUAL MOTION. 87 



The purpose of the Department in ordering an examination of Professor 

 Gamgee's ice making machine was not to obtain an opinion on its ice making 

 merits, but one as to whether his observations on the behavior of ammonia in the 

 process were sufficiently accurate to warrant his inference of the practicability of 

 constructing a successful zeromotor for industrial uses — a motor, in short, destined 

 to supersede the steam engine. Accordingly I have closely investigated the work- 

 ing of the apparatus. The facts of hquid ammonia gasifying at ordinary atmos- 

 pheric temperature under very high pressures, and of that gas undergoing very 

 great refrigeration when used expansively in doing work, are not called in ques- 

 tion by any one. Both are well known phenomena. The special fact to be ob- 

 served was whether any part of the ammonia which entered the cylinder as a gas 

 left it as a liquid, and, so far as the form of the apparatus allowed any observation 

 to be made, such appeared to be the case. The possibility of the invention of a 

 new motor of incalculable utility would seem to be established, and in view of the 

 immense importance of the subject to the Navy and to mankind at large, I strong- 

 ly recommend it to the serious attention of the Department, suggesting further 

 that whatever facilities the Department can, in its opinion, consistently extend, 

 be allowed to Professor Gamgee for the continuance of his important experimen- 

 tal inquiries in the Washington Navy Yard. He is most anxious to bring his in- 

 vention, with the least possible delay, to a crucial test by the completion of the 

 necessary mechanism, and its submission to any board of experts which may be 

 ordered experimentally .to ascertain its merits. For this purpose he proposes to 

 use such parts of his present ice making machine as can be re-combined in his 

 zeromotor, adding the other necessary parts, and thus producing, with but little 

 loss of time, an embodiment of his idea that will by simple trial show whether an 

 unquestionably correct theory has been successfully reduced to practice. 



Professor Gamgee has perfected the calculations and drawings for the mecha- 

 nism required to give practical effect to his invention, and there remains only to 

 execute the mechanical work. He proposes to use the steam cylinder of his ice- 

 making machine as the ammonia cylinder of the new motor, the present ammonia 

 condenser, and the present ammonia boiler as a low pressure boiler, adding an- 

 other ammonia boiler as a high pressure boiler. These, together with the ejector 

 between the condenser and the low pressure boiler, a small pump for pumping 

 liquid ammonia from the low pressure to the high pressure boiler, etc. , will con- 

 stitute the zeromotor — a machine, as will be apparent from this brief description, 

 of the simplest, cheapest, and most manageable kind. 



In the high pressure boiler the liquid ammonia will be gasified by the heat in 

 water of atmospheric temperature to the pressure normal to that temperature. In 

 the low pressure boiler ammonia is kept at a considerably less tension than in the 

 high pressure boiler, and with this lower pressure ammonia gas the engine is 

 operated, the gas being used as expansively as practicable and made to do work 

 during its expansion, thereby becoming refrigerated, greatly reduced in bulk, 

 and partly liquefied. Immediately on being exhausted the cooled and shrunken 



