24 LEADING AMERICAN MEN OF SCIENCE 



"From the result of these computations it appears, that the 

 quantity of heat produced equably, or in a continual stream (if I 

 may use that expression) by the friction" in this experiment was 

 greater than that produced by the continuous burning of nine 

 wax candles each f inches in diameter. 



Finally Rumford takes the great step of connecting the heat 

 and mechanical work, by calculating the power used in turning 

 the borer and producing the heat by friction. The relation be- 

 tween these two forces of energy, or the dynamical equivalent of 

 heat, he determined as 847 foot-pounds, that is, the work done by 

 raising one pound weight 847 feet will, if converted into heat, 

 raise the temperature of one pound of water one degree Fahren- 

 heit. Considering when it was done, and the crudity of the appara- 

 tus, this is an astonishingly accurate result, for it is only about 

 10% above the figure now accepted, 779. Forty-two years elapsed 

 before it was more accurately determined by Joule as 772 foot- 

 pounds. It is now called the joule, although it might well bear 

 the name of the rumford instead. 



As an example of the way Count Rumford sums up his evidence 

 and draws from his experiments a clear and logical conclusion, 

 the closing paragraphs of this historic paper are here given. It 

 will be noted that his language is so simple and direct that the 

 most unscientific reader can follow his demonstration of the new 

 theory. 



"By meditating on the results of all these experiments we are 

 naturally brought to that great question which has so often been 

 the subject of speculation among philosophers; namely, What is 

 Heat? Is there any such thing as an igneous fluid? Is there 

 anything that can with propriety be called caloric? 



"We have seen that a very considerable quantity of Heat may 

 be excited by the friction of two metallic surfaces, and given off in 

 a constant stream or flux in all directions without interruption or 

 intermission, and without any signs of diminution or exhaustion. 



"From whence came the Heat which was continually given off 

 in this manner in the foregoing experiments? Was it furnished 

 by the small particles of metal detached from the larger solid 

 masses on their being rubbed together ? This, as we have already 

 seen, could not possibly have been the case. 



