No. 200.] 
137 
to be located at Musquito Cove, at which 300,000 bricks have been 
made during a year 
Clay occurs at and near Rossvillcj on Staten Island. It is the dark 
blue astringent clay, containing a great proportion of pyrites in nodules 
and grains. When exposed to the air for a time, it acquires a green 
efflorescence, which has the appearance, at a few feet distant, of serpen- 
tine, but which is in reality sulphate of iron. The pyritous masses in the 
clay are often covered with beautiful brilliant druses of crystals of sul- 
phuret of iron. Lignite also abounds in this clay. 
Small slides were seen in the valley of a stream near Rossville, which 
led me to examine for clay. This pyritous astringent blue clay is simi- 
lar in its general characters to that of Cheesequake and Matavan Point, 
on the Jersey shore, and it appears to have a similar geological position. 
This clay is extensively developed in New- Jersey, and there it overlies 
the marl deposits.^ This stratum is, then, one of much economical in- 
terest, for if marl beds of easy access can be found, they will be of 
great value. 
Springs J Wells ^ SfC. 
The springs of Long Island are numerous, and present some pheno- 
mena worthy of consideration. Around the heads of the bays and re-en- 
terings of the coast along the north shore of Long Island, copious springs 
break out very little above tide water level. In some instances they 
boil up through the sand and gravel so as to form a brook at once; in 
others, several springs break out at the foot of the bank, and uniting 
their waters, form a stream. The numerous mills and manufactories on 
the shores of many of the re-enterings of the northern coast of Long 
Island, and which have no apparent streams communicating with their 
ponds, to renew the supply of water, attract the attention of most ob- 
servers. The water of these springs is very pure, in consequence of its 
having been filtered through beds of nearly pure silicious sand and gra- 
vel. It is thrown out at the level of tide water, or at a higher level, 
where there are strata impermeable to it. Some of the most remarka- 
ble of these springs which are applied to manufacturing purposes, are 
about Hempstead Harbor, at the head of Little Neck Bay, at the head 
of Cold Spring Harbor, and the S. W. part of Oyster Eay Harbor. 
In most parts of Long Island, water is not found in quantity, and is 
not permanent, except at about the level of the ocean, in consequence 
of the porous nature of the strata. 
* Vide Rodger's Geol. Rep. of New-Jersey, p. 183. 
I Assem. No. 200.J 14 
