108 Trans. Acad. Sci. of St. Louis. 



Motion they mean the Motion of the Whole Bodies, which is 

 the Cause of the two Bodies rubbing against each other; but 

 if bv Motion they mean the Motion of their insensible Parts, I 

 think they have not said enough : for the Motion of these 

 Parts, is the very Heat itself of those Bodies." 



Sixty-nine years later, in 1798 appeared Count Rumford's 

 paper in the Transactions of the Royal Society, in which he 

 gives an account of experiments made in the boring of brass 

 cannon at Munich while he was in the service of the Elector 

 of Bavaria. He tested the heat capacity of the metal borings 

 and found them the same as the cuttings made with a sharp 

 saw where little heat was produced. He concluded that the 

 heat obtained in the boring was not a substance, caloric, 

 squeezed out of the borings, and concludes : — 



"It is hardly necessary to add, that anything which any 

 insulated body or system of bodies can continue to furnish 

 without limitation, cannot possibly be a material substance; 

 and it appears to me to be extremely difficult, if not quite 

 impossible, to form any distinct idea of anything capable of 

 being excited and communicated in those experiments, except 

 it be motion." 



The advance which this great man made, was in the meas- 

 urement of heat quantities. He compared the quantity of 

 heat produced by the work of a horse, in driving the drill 

 used in boring the cannon, with that which could be realized 

 by burning the feed which the horse would require during the 

 interval, and also with that produced in the burning of a 

 definite quantity of wax in candles of specified size. This 

 comparison was made by determining the amount of water 

 heated from freezing to boiling. 



This man Benjamin Thompson, born in Woburn, Mass., 

 1753, was one of the great men whom this country has pro- 

 duced, and whom it does not know. He was in charge of an 

 academy at Rumford, afterwards Concord, N. H., in 1770. 

 At the outbreak of hostilities he applied for a commission in 

 the revolutionary army, but he was accused of toryism and 

 left the country in disgust. Later his distinguished serv- 

 ices to the English government and people led to his being 

 knighted. Soon after he entered the service of Bavaria, 



