64 Dr. Lathrop’s account of the springs and wells in Boston. 
On this peninsula there are what T shall take the liberty of calling, 
the upper and the nether springs. ‘The upper springs are those which 
are found in the-hills, and at a moderate distance from the surface, to- 
gether with those which discharge their waters, at openings which they 
have worked for themselves. The nether springs are those which 
are found under a body of clay, from 80 to 120 feet deep. 
We are now to inquire for the sources of the springs of both 
kinds, which are found on the peninsula, and eye 
sydeavour to account 
for the height at which water rises in the wells. ~The sources, I be- 
lieve, cannot be found on the peninsula. By the laws of hydrostatics, 
water can rise in wells no higher than the reservoir. Some of the an- 
cients supposed all springs and fountains of fresh water have their ori- 
gin in the sea, and that in passing subterraneous ducts, the sea water 
loses its saltness by percolation. But as sea water can be admitted 
into the wells in Boston, only through veins of sand or gravel, it is not 
conceivable, that in passing so short a distance, (in many places buta 
few feet) it can lose all its saltness. But were that supposable, there 
is an objection to the theory from the eee to which spring water 
rises. 
‘The sea can raise water only to its own level ; whereas the water 
‘rises in some of the wells in Boston 75 or 80 feet above the level of 
the sea. Were the hills on the peninsula high and large eneugh to 
contain caverns in their bowels, or admit of basons, for ponds on their 
tops, the quantities of water, received direct from the atmosphere, 
might be sufficient to keep the springs at their foot always full. But 
Beacon Hill, the highest of the three, is only 138 and a half feet, Its 
shape is such, that the vapours which are attracted to it, and the rains | 
which fall upon it, must run quickly down its steep sides to the sea 
While the electric principle, which the upper strata possess, may be 
continually attracting the surrounding vapours, the sands, of which 
