484 



Inquiry concerning the Source of 



Quantity of ice-cold water which, 

 with the given quantity of Heat, 



Of the Heat excited there appears to have m 'g |u have been heated 180 de- 

 grees, or made to boil. 

 been actually accumulated, In avoirdupois weight. 



In the water contained in the wooden box, 



i8f lb., avoirdupois, heated 150 degrees, u,. 



namely, from 60 to 210 F 15.2 



In 113.13 lb. of gun-metal (the hollow cylinder), heated 

 1 50 degrees ; and, as the capacity for Heat of this metal is to 

 that of water as o. 1 100 to i.oooo, this quantity of Heat would 

 have heated 12^ lb. of water the same number of degrees . 10.37 



In 36.75 cubic inches of iron (being that part of the iron 

 bar to which the borer was fixed which entered the box), 

 heated 150 degrees; which maybe reckoned equal in ca- 

 pacity for Heat to 1.21 lb. of water ..... i.oi 



N. B. No estimate is here made of the Heat accumulated 

 in the wooden box, nor of that dispersed during the experi- 

 ment. 



Total quantity of ice-cold water which, with the Heat 

 actually generated by friction, and accumulated in 2 hours 

 and 30 minutes, might have been heated 180 degrees, or 

 made to boil . . . . . . . . .26.58 



From the knowledge of the quantity of Heat actually 

 produced in the foregoing experiment, and of the time 

 in which it was generated, we are enabled to ascertain the 

 velocity of its production, and 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. 



In one of Dr. Crawford's experiments (see his Trea- 

 tise on Heat, p. 321), 37 lb. 7 oz., Troy, = 181,920 

 grains of water, were heated 2^ degrees of Fahrenheit's 

 thermometer with the Heat generated in the combus- 

 tion of 26 grains of wax. This gives 382,032 grains of 

 water heated I degree with 26 grains of wax, or 14,693^! 

 grains of water heated I degree, or 1 ^|^ 3 = 81.631 



