482 Inquiry concerning the Source of 



the water out of it, or deranging any part of the appa- 

 ratus. 



Everything being ready, I proceeded to make the ex- 

 periment I had projected in the following manner. * 



The hollow cylinder having been previously cleaned 

 out, and the inside of its bore wiped with a clean towel 

 till it was quite dry, the square iron bar, with the blunt 

 steel borer fixed to the end of it, was put into its place ; 

 the mouth of the bore of the cylinder being closed at 

 the same time by means of the circular piston, through 

 the center of which the iron bar passed. 

 . This being done, the box was put in its place, and the 

 joinings of the iron rod an'd of the neck of the cylinder 

 with the two ends of the box having been made water- 

 tight by means of collars of oiled leather, the box was 

 filled with cold water (viz. at the temperature of 60), 

 and the machine was put in motion. 



The result of this beautiful experiment was very strik- 

 ing, and the pleasure it afforded me amply repaid me for 

 all the trouble I had had in contriving and arranging the 

 complicated machinery used in making it. 



The cylinder, revolving at the rate of about 32 times 

 in a minute, had been in motion but a short time, when 

 I perceived, by putting my hand into the water and 

 touching the outside of the cylinder, that Heat was gen- 

 erated ; and it was not long before the water which sur- 

 rounded the cylinder began to be sensibly warm. 



At the end of I hour I found, by plunging a ther- 

 mometer into the water in the box (the quantity of 

 which fluid amounted to iB.yylb., avoirdupois, or 2| 

 wine gallons), that its temperature had been raised no 

 less than 47 degrees ; being now 107 of Fahrenheit's 

 scale. 



