588 On Evaporation. 
_ The use of this table will appear from the 
following problems : 
PROBLEM I. 
Having given the temperature at which the 
aqueous atmosphere begins to be condensed into 
water, and the temperature of the air, to find 
the quantity of water that would be evaporated 
in a minute from a vessel of 6 inches diameter. 
Solution. Subtract the grains opposite to 
the lower temperature from those opposite to 
the higher one, in the first, second or third 
column of grains, according to the strength 
of the wind, and the remainder will be the 
quantity evaporated in a minute, under those 
circumstances, nearly, 
Example. Let the point of condensation be 
52°, the temperature of the air 65°, with a mo- 
derate breeze, 
The number opposite 52°in the second column 
of grains is 2. 06, and that opposite 65° is 3. 16; 
the difference, 1, 1 grain, is the evaporation 
per minute. 
PROBLEM Ii. 
Having given the quantity evaporated in a 
minute, found by experiment, and the temper- 
ature of the air, to find the force of the aqueous 
atmosphere, and the point of condensation. 
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