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This great Inequality of the Strength of the Sur- 
face-Water put me upon trying whether the Water 
at the Bottom of the Well, near the Springs, were 
ftronger than the Surface-Water. And in order to 
this, I procured, ‘Dec. xi, a Bottle of the Water 
near the Bottom, which was ten Feet below the Sur- 
face of the Water; which was done by tying an 
empty Bottle to the End of a long Pole, with a Line 
fixed to the Cork, to pull it out when at the Bottom, 
for the Water to fill it: And I had at the fame 
time another Bottle full of the Surface-Water. The 
lower Water yielded 81 Grains; the Surface-Water 
but 48 Grains ; and it was the fame upon a fecond 
Evaporation of thofe Waters. Hence we fee how 
much ftronger the Water near the Bottom is, than 
at the Surface ; even when the preceding Rains have 
been but moderate ; for they had not as yet been 
fufficient to raife the Springs in this Country much. 
Hence we fee that the ftronger lower Water may 
eafily be come at by means of a Pump ; as alfo, that 
the upper Land-Springs, foon after Rains, make the 
Water near the Surface weaker: But, in long dry 
Weather, when there are no Land-Spring^, the Sur- 
face-Water, and that at the Bottom, are nearly of 
an equal Strength : For it requires Time for the fa- 
line mineral Virtue to be equally diffufed thro* a 
Mafs of that Depth of Water, whofe upper Part is 
inccflantly weakened by a Land-Spring of frefh 
Water. 
Hence we fee howadvifeablc it is, in order to keep 
out the Land-Springs, to dig a narrow Trench fomc 
Feet Depth, round the Well, to be filled with ftiff 
Clay well rammed. 
The 
