200 
of making. This apparatus consisted of a small cauldroq, 
of tinhed iron, well polished on the outside, and of a coni¬ 
cal form, with a circular bottom, seven inches and ten lines 
in diameter, and a little swelled inwardly. This cauldron 
was four and a half inches deep, and six inches wide at the 
top, and tapered off above like a wine bottle, having a long 
neck, in which was placed a mercurial thermometer, which 
served to indicate the temperature of the liquid which the 
cauldron contained. I placed this little cauldron upon a 
small board, an inch thick, which had a hole in its centre, 
about three inches in diameter. This board was attached 
to an upright post, in such a manner that it could be fixed 
at any desirable height; the lamp was placed below it on 
a table. 
Having put into this small cauldron 2000 grammes of 
water, at the temperature of 64° Fahrenheit (which was 
also the temperature of the room in which the experiment 
was made) a small candle of a known weight placed in its 
vessel, and floating on the water where it was placed, was 
lighted, and put afterwards under the cauldron, at such a 
distance that the point of the small flame reached on a line 
with the inferior surface of the board on which the cauldron 
was placed, and below the centre of the hole made in the 
board, to give passage to the flame. 
The following is the result of this experiment: The 
small candle having burnt under the cauldron for fifty-two 
minutes and fifteen seconds, the thermometer indicated the 
water to have acquired the temperature of 75° Fahrenheit, 
the candle was extinguished, and having been wiped and 
weighed, it was found to have lost during this experiment 
1.55 grammes of wax. 
Exfi. 17..—The cauldron having been emptied and cooled, 
was filled again with 2000 grammes of water, at the tem¬ 
perature of 65° Fahrenheit, and placed on the board. 
A good candle of the ordinary size, weighing three 
ounces, properly placed under the cauldron, was lighted. 
