138 
GEOLOGY OF THE FIRST DISTRICT. 
Street, corner of Second, Third and Fourth avenues, the rock appears ; and the soil, as we 
go northward, continues to grow thinner and. thinner. 
“ As we approach the East river from any point in the middle of the island, between First 
and. Twentieth-streets, the rock dips down to a depth of ninety to one hundred feet below 
grading, as evinced in the shafts sunk in this part of the city. 
“The diluvium and stratified sand and gravel, it appears, extends on the west side of the 
island as far as Thirty-first street, and on the east side to Sixteenth-street; and notwithstanding 
this formation is found in every other section of the island, it is in comparatively small quan¬ 
tities.”* 
The alluvial meadows and valleys of New-York island, as described by Prof. Gale, cover 
the quaternary deposits; and some parts of those valleys expose the quaternary, without 
being covered by alluvion. They are grouped together by him under the name of alluvium. 
The following extracts from his report, give information on the thickness and extent of the 
alluvial and quaternary of some parts of the island. 
“ There are three principal beds or valleys of alluvium that demand particular description. 
The first, lying in the very centre of the city, includes nearly the whole length of Centre- 
street with Elm on the west, and Orange and Mulberry-streets on the east, to the neighbor¬ 
hood of Canal-street. This valley was formerly called the Collect, as it was a receptacle for 
the draining of the adjoining higher grounds. In some portions it was a mere quagmire, and 
in others a collection of stagnant water fifty or sixty feet deep, and is said by some of the 
oldest citizens to have had an outlet communicating with the East river along what is now 
called Roosevelt-street; and another, with the Hudson across the Lispenard meadows, cross¬ 
ing Broadway at what was then called the Stone bridge (now corner of Broadway and Canal- 
street.) The Lispenard meadows extended from Broadway to the Hudson, and from the 
vicinity of St. John’s church to Spring-street on the north, including the range of Thompson, 
Laurens and Wooster-streets. 
“ This first valley being a fresh water alluvion, and a quagmire originally, was of great 
depth, as has been recently proved by soundings made by Mr. Disbrow, in the place now 
occupied by the Halls of Justice in Centre-street, between Franklin and Leonard-streets, 
where iron rods were sunk forty feet through artificial earth, thirty feet through black mud, 
five to ten feet of blue clay, then a bed of gravel resting on the rock. Still farther south, at 
the Manhattan water-works, on Centre, between Reade and Duane-streets, seven shafts were 
sunk thirty feet each in coarse diluvial gravel without reaching the rock. The water supplied 
by the Manhattan Company is by no means the best in quality, but is used for want of better 
in culinary operations in a considerable portion of the southern part of the city. 
“ The black mud brought up from the lower part of the strata of the Collect was as salt as 
the waters of the river, though very good water was obtained at a higher level on the outskirts 
of this valley. This fact is generally explained, by considering the water from the gravel 
* Geological Report of New-York, 1839, pp. 184, 187. 
