$6 VegHahle Statickf. 
ter, /. e, h of an inch each day, at a mean 
rate 5 but the earth in a fummer s day evapo- 
rates 4-0 of an inch ; fo the evaporation of 
a furface of water, is to the evaporation of 
a furfacc of earth in fummer, as 10:3. 
. The quantity of Rain and Dew which 
falls in a year is at a medium 22 inches: 
The quantity of the earth’s evaporation in 
a year is at leaft 9 + i inches, fince that 
is the rate; at which it evaporates in a fum- 
mer's day : From which 9 + i inches is to 
be deducted 3. 39 inches for circulating 
daily Dew; there remains 6. 2 inches, which 
6, 2 inches deduced from the quantity of 
Rain -which falls in a year , there remains 
at leaft 16 inches depth, to replenifh the 
earth with moifture for vegetation, and to 
fupply the Springs and Rivers. 
In the cafe of the hop-ground, the eva- 
poration from the hops may be confidered 
only for 3 months at t4-t part of an inch 
each day, which will be tV of an inch ; 
but before we allow 6. 2 inches vapor to eva- 
porate from the furfacc of the ground, 
which added to tV inch gives, 7. i inches, 
which is the utmoft that can be evaporat- 
ed from a furface of hop-ground in a year. 
So 
