480 Life of Coiint Rumford. 



as it revolved and the borer with the piston that was 

 turned against the bore of the cylinder. Soon the water 

 which surrounded the cylinder began to be warm. In 

 two hours and a half " IT ACTUALLY BOILED ! " 

 The philosopher shall speak for himself: 



" It would be difficult to describe the surprise and astonish- 

 ment expressed in the countenances of the bystanders on 

 seeing so large a quantity of cold water heated and actually 

 made to boil without any fire. Though there was, in fact, 

 nothing that could justly be considered as surprising in this 

 event, yet I acknowledge fairly that it afforded me a degree of 

 childish pleasure which, were I ambitious of the reputation of a 

 grave philosopher, I ought most certainly to hide rather than 

 discover." 



He then proceeds to estimate the total quantity of 

 heat generated, accumulated, and dispersed by the ex- 

 periment in the water and in the apparatus. 



From the quantity of heat generated in the last ex- 

 periment, and from the time required for its production, 

 Rumford next sought to ascertain the velocity of its pro- 

 duction. He wished also to determine how large a fire 

 must have been, or how much fuel must have been con- 

 sumed, in order that in burning equably it should have 

 produced by combustion the same quantity of heat in 

 the same time. He found that nine wax candles of 

 three quarters of an inch in diameter, all burning to- 

 gether with clear bright flames, would not produce so 

 great a quantity of heat as had been excited in the 

 above-described experiment. His computations showed, 

 further, how much heat might be produced through 

 mechanical contrivances, employing the strength of a 

 horse, without either fire, light, combustion, or chem- 

 ical decomposition, to be had recourse to in case of 



