On the Powers of Steam, &c. 113 



being thus condensed, falls down in drops upon the 

 stove, by which it is again raised in vapour, and ap- 

 plied to the bottom of the kettle, where it is condensed 

 as before. 



This small quantity of water, alternately suffering 

 evaporation and condensation, is, by this means, not 

 dissipated for many minutes, even by a very hot 

 stove ; but, passing constantly backwards and for- 

 wards, between the stove and the kettle, becomes a 

 carrier of heat, in the same manner that pieces of 

 gold-leaf, &c, become carriers of electricity between 

 two plates, one being suspended over the other. To 

 prove that this process actually takes place, we have 

 only to raise the kettle from the stove ; the water is 

 dissipated in an instant, having no longer any thing to 

 condense its vapour. To set this phenomenon in a 

 clear point of view, and to show how quickly water 

 may, by this method, be heated, I got two pewter 

 basons, of the same shape, size, and thickness. In- 

 to each of these I put thirty-four ounces of water, 

 the temperature of which was 33, by Fahrenheit's 

 thermometer, or one degree above the freezing point. 

 A large spoonful of water being poured upon a stove, 

 very moderately heated, one of the basons was im- 

 mediately placed upon it. The other bason was, at 

 the same time, set on the same stove, but without 

 any water under it. In four minutes, the water in the 

 bason, to which the steam had been applied, had rose 

 to 60, whilst the other had only got to 48 ; and, in 

 five minutes, they were at 68 and 50. 



VOL. I. part ii. r 



