332 NINETEENTH CENTURY. PT. ill. 



the water warm, so it was clear they had not drawn any 

 heat from that fluid. 



He now began to suspect that Bacon and Locke might 

 be right, and that the rubbing together of the two metals 

 might set their particles vibrating in some peculiar way so 

 as to cause what we call heat. If this were so, then by great 

 friction he ought to be able to produce any amount of heat, 

 and to prove this he tried the following experiment. 



He took a large piece of solid brass the shape of a can- 

 non, and partly scooped out at one end. Into this he fitted 

 a blunt steel borer, which pressed down upon the brass with 

 a weight of ten thousand pounds. Then he plunged the 

 whole into a box holding about a gallon of water, into which 

 he put a thermometer, and fastening two horses by proper 

 machinery to the brass cylinder he made them turn it round 

 and round thirty-two times in a minute, so that the borer 

 worked its way violently into the brass. Now notice what 

 happened : When he began the water was at 60 F., but 

 it soon grew warm with the heat caused by the friction 

 of the borer against the brass. In one hour it had risen 47 

 up to 107 Fahr. ; in two hours it was at 178, and at the 

 end of two hours and a half // actually boiled. 



1 It would be difficult/ writes Rumford, ' to describe the 

 surprise and astonishment of the bystanders on seeing so 

 large a quantity of water heated and actually made to boil 

 without any fire,' and he adds that he himself was as delighted 

 as a child at the success of the experiment ; and we can 

 scarcely wonder, for he had proved the grand fact that 

 motion can be turned into heat ! 



Rumford afterwards calculated that the friction caused 

 by one horse pulling round the cylinder against the borer 



