OF ARTS AND SCIENCES : MAY 9, 1865. 497 



upon the revolving shaft, so tliat the heat must have resulted wholly 

 from the destruction of mechanical motion. The immense moving 

 power of the wheel, instead of being directed wholly into its appro- 

 priate channel, was in part transformed into that mode of atomic mo- 

 tion called heat. In the second place, the temperature attained was at 

 least the welding-point of iron, and this, too, although the heated metal 

 was immersed in a stream of flowing water. It is undoubtedly true, 

 that the spheroidal condition of the water would greatly retard the loss 

 of heat, but still the loss must have been exceedingly rapid. Now the 

 loss, even at the highest temperature attained, must have been fully 

 supplied by the heat generated during the same time ; and this must, 

 therefore, have been evolved with equal rapidity at the surfaces of 

 friction. No change in the molecular condition of the iron, and no abra- 

 sion of the metal, is at all sufficient to account for this continuous, pro- 

 longed, and immensely rapid evolution of heat, and the facts force upon 

 us the conclusion, that the destruction of mechanical motion is the one 

 and only efficient cause. Moreover, if we admit the generally received 

 principle of mechanics, that motion cannot be annihilated, the conclu- 

 sion that heat is a mode of motion is equally irresistible. Lastly, it is 

 evident that the facts here stated perfectly accord with the well-known 

 experiments of Rumford and Davy ; only since the moving power of 

 the Merrimack turbine is so much greater than that employed by 

 these distinguished experimentalists, the results which I have had the 

 pleasure of exhibiting are more striking and conclusive than any 

 which have been previously obtained. 



Five bundred and fifty-second fleeting. 



May 9, 1865. — Monthly Meeting. 



The President in the chair. 



The Recording Secretary read letters relative to exchanges. 

 The proposition of the Rumford Committee, that the Rumford 

 Premium be awarded to Professor Treadwell for his improve- 

 ments in the management of heat, which had been referred to 

 this meeting, was then brought up for discussion, and was re- 

 ferred to the Annual Meeting for the action of the Academy. 



