Vegetable Statich. 57 
So that of 22 inches depth of rain, there re- 
mains 15 inches to fupply fprings; which 
are more or lefs exhaufted, according to 
the drynefs or wetnefs of the year. Hence 
we find that 22 inches depth of rain in a 
year is fufficient for all the purpofes of na-* 
ture, in fuch flat countries as this about 
Teddington near Hampton • court. But in 
the hill countries, as in Lancajhire^ there falls 
42 inches depth of rain-water ; from which 
dedufting 7 inches for evaporation , there 
remains 35 inches depth of water for the 
fprings; befides great fupplies from much 
more plentiful dews, than fall in plain coun- 
tries : Which vaft ftores feem fo abundantly 
fufficient to anfwer the great quantity of 
water, which is conveyed away, by fprings 
and rivers, from thofe hills, that we need 
not have recourfe, for fupplies, to the great 
HtpyfSy whofe furface, at high water, is fur- 
mounted fome hundreds of feet by ordi- 
nary hills, and fome thoufands of feet by 
thofe vaft hills, from whence the longeft and 
great eft rivers take their rife. 
Exper, 
