6 Experiments on the 
50 seconds, and the last 10° in 3 minutes and 
52 seconds, which was the longest period.—’ 
The shortest time of passing through 10° was 
2 minutes and 37 seconds. In most of the 
experiments, however, a little more time 
elapsed, as the temperature increased; but 
this seems to be accounted for by the greater 
rapidity with which the boiler cools, as its 
temperature increases beyond that of the sur- 
rounding atmosphere, and perhaps also by the 
lesser rapidity with which it heats, as the 
temperature approaches nearer to that of the 
lamps. I conceive however that it may be taken 
as a reasonable approximation to the truth that, 
by an equal and uniform application of the 
same quantity of heat, water will rise through 
the several degrees of the thermometer in 
equal times, and that to a temperature consi- 
derably above the boiling point, if confined in 
a close vessel. It appears, from the above 
experiments, that the temperature rises equally 
with the expenditure of the fuel, or nearly so, 
and it was before shewn, that the force of the 
steam increases in a much more rapid degree ; 
but it is to be remembered, that the process is 
here carried on in a close vessel, and no steam 
escapes during the experiment, which I shall. 
advert to more particularly by and by. 
