8 ao Report of the Committee 
faft or very gently ; and what difference there was, was 
not always the fame way, as the thermometer fometimes 
flood higher when the water boiled faft, and fometimes 
lower. The difference, however, feldom amounted to 
more than -^th of a degree, unlefs a confiderable part 
of the fides of the pot were expofed to the fire ; but in 
fome trials which we made with the fhort thermometers 
in the fhort pot, with near four inches of the fide of the 
veffel expofed to the fire^, they conftantly flood lower 
when the water boiled faft than when flow, and the 
height was in general greater than when only the bot- 
tom of the pot was expofed to the fire. This difference 
however was not perceived in the trials of the long 
thermometer in the deep pot, as there feemed very little 
difference in the height whether the water boiled faft or 
flow, or whether more or lefs of the fide of the pot was 
expofed to the fire. The greateft difference obferved in 
the fame thermometer, on the fame day and in the fame, 
water, according to the different manner of trying the 
experiment, was half a degree. 
(d) In all our experiments, the water was boiled over a portable black-lead 
fftrnace, covered with an iron plate, which had a hole cut in it juft big enough: 
to receive the bottom of the pot; fo that, by palling the bottom through this 
hole to a greater or lefs depth, we could expofe more or lels of the fides to the 
fire. In the other experiments, not more than one inch of the fides was ever: 
expofed to the fire. 
We 
