On Evaporation. 579 
The extremes that have thus been noticed are 
go and 45 grains per minute: but were the ex. 
periment tried in the open air in high winds, I 
am inclined to believe from a comparison of the 
observations, that an evaporation of 50, 55 or 
even 60 grains per minute might be observed, 
~ On the Evaporation of Water below 212°. 
I have frequently tried the evaporation at all 
the temperatures below 212°: it would be tedi- 
ous to, enter into detail of all the experiments, 
but shall give the results at some remarkable 
points. In all the high temperatures I used the 
vessel above mentioned, keeping a thermometer 
in it, by which I could secure a constant heat, 
or at least keep it oscillating within narrow 
limits. 
‘The evaporation from water of 180° was from 
18 to 22 grains per minute, according to circum- 
stances; or about 4 of that at 212°, 
At 164° it was about 4 of the quantity at the 
boiling temperature ; or from 10 to 16 grains per 
Minute, . 
At 152° it was only ; of that at boiling; or 
from 8 to 12 grains, according to circumstances, ~ 
