50 THE ROYAL INSTITUTION. [CHAP. I. 



the Rhine, but the distance between Munich and 

 Mannheim is so great that it would have cost more to 

 have sent the Bavarian guns to Mannheim to be re- 

 founded and to have brought them back than was 

 required to defray the expense of establishing a new 

 manufactory for the construction of artillery in Bavaria. 



A foundry was accordingly established at Munich, 

 and neither pains nor expense were spared to make 

 it as perfect as possible. A most excellent machine 

 was erected for boring cannon, with workshops ad- 

 joining to it for the construction of gun-carriages and 

 ammunition waggons. 



Whilst engaged in superintending the boring of the 

 cannon he was struck by the heat produced in a brass 

 gun and with the still more intense heat of the 

 metallic chips separated by the borer. 



He says : ' The more I meditated on these phenomena 

 the more they appeared to me to be curious and inte- 

 resting. A thorough investigation of them seemed 

 even to bid fair to give a further insight into the 

 hidden nature of heat, and to enable us to form some 

 reasonable conjectures respecting the existence or non- 

 existence of an igneous fluid. 



4 Whence comes the heat actually produced ? 



' Does it come from the metallic chips ? If so, their 

 capacity for heat must be changed ; but by repeated ex- 

 periments I found that no change of capacity was caused 

 by the boring. Determination of the actual heat pro- 

 duced and of the amount of chips showed that there was 

 no relation between them. That the heat did not come 

 from the gun itself was shown by the absence of every 



