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f Assembly 
very much deteriorated, and is now said to be even more saline than 
that of the neighboring river. 
Oh the west side of the island, at Washington market, which is on 
the west side of Washington-street, between Fulton and Vesey-streets, 
a shaft was sunk 10 feet through artificial earth, 50 feet through river 
mud containing decayed vegetable matter, sands, clays, &c. in thin 
alternating strata, 10 feet of sands and gravel, when the rock was 
reached at 70 feet from the surface. 
Again, at the corner of Grand and Wooster-streets, a shaft was sunk 
40 feet through artificial earth, then 20 feet of mud, clays, and sands 
highly charged with decaying vegetable matter; then 6 feet of fine blue 
clay; and lastly, 6 feet more of coarse sand and gravel, when good 
water being obtained, the borings were discontinued at the depth of 
72 feet from the surface. This depth was considered as at, or at least 
as very near, the surface of the rock, from the fact that in almost all 
cases where the rock was reached at great depths through similar strata, 
it was found covered with a bed of gravel or sands, like that above 
mentioned. 
In College place, directly north of Columbia College, which is on 
more elevated ground than the market, the rock was reached at the 
depth of 80 feet, through 20 feet of diluvium and 60 feet of stra- 
tified sand and gravel alternating. If we follow the high range of 
grounds in a longitudinal direction, as in the neighborhood of Broad- 
way, though we have fewer data from which to judge, yet it is be- 
lieved that the rock here approaches nearer the surface than in the 
places above mentioned. This is inferred from the fact that the direc- 
tion of Broadway corresponds with that of the strike of the strata, and 
is generally more elevated than the grounds on either side of it, and the 
contour of the rock follows, it is believed, that of the loose earth which 
covers it. 
At the old rock well near Trinity church, the shaft was sunk 26 feet 
through diluvial gravel and sands, where the rock was reached, though 
not penetrated, and good and permanent springs of water obtained. 
At the City Hall the shaft was sunk 90 feet to the rock, but is in the 
district of the Collect, (see vertical section No. 1.) The celebrated 
well, corner of Bleecker-street and Broadway, is 448 feet deep; 42 feet 
through stratified sands and gravel, and 406 feet in solid rock, having 
the usual character of the gneiss of the island. The bore of the shaft 
is 7 inches diameter, and yields 120,000 gallons in 24 hours, according 
