TERRA-COTTA, BRICK, ETC. 
129 
paper. In Massachusetts, clay is citecl as occurring at North- 
ampton, and at Martha’s Yineyard. Granulär quartz, another 
important ingredient of the hody, is mined in Berkshire 
County. 
The early exportation of samples of clay from the Southern 
States to England, has been noticed. No doubt extensive 
deposits of valuable clays exist there. Good clays are found 
in California. 
Extensive deposits of the finest clays for pottery purposes 
are found at many points in the State of New Jersey, and 
including the varieties known as fire-clay, paper-clay, and 
alum-clay, they form a continuous beit extending obliquely 
across the State from Raritan Bay and Staten Island Sound 
on the east; to the Delaware River on the west.* The pits 
dug for these clays are chiefly within areas of uo great extent 
near Woodbridge, Amboy, Bonhamtown, Washington and 
Trenton, but explorations have shown the existence of other 
places where they can be dug with profit. They are, in gen 
eral, overlaid with superficial beds of drift of sand and gravel. 
The beds are extensively mined, not only for pottery and fire- 
brick, but for shipment. Large quantities are used in New 
York, Philadelphia and Boston, for the manufacture of alum. 
Much of the whitest and purest is sold to the manufacturers 
of paper-hanging for facing wall -papers. By far the 
greatest consumption is in the manufacture ot fire-brick, 
especially at Perth Amboy, South Amboy, and at Trenton. 
In one township, Woodbridge, over fifty thousaud tons of 
clay were raised in 1865. 
Fire-sand, moulding-sand, kaolin and feldspar, offen occur 
with these beds of clay and in workable quantities. llie ma- 
terials used for fire-brick consist of about five-eighths raw 
* The limits of this heit are deflned by the state geologists of New Jersey, as 
follows: “ The northern limit is marked hy the outcropping red shulo and sandstone 
of the triassic formation, following an almost straight line from Woodhridge, South 
west hy Bonhamtown, to the mouth of Lawrence’s Brook on the Raritan River; along 
this stream, nearly tothe Monmouth Junction, and thence north of the railroad near 
Penn’s Neck and Baker’s Basin, to the Delaware River at Trenton. The Southern 
houndary of this suh-division of the cretaceous formation is not well deflned in conse- 
quenee of the superficial heds of drift which cover it. Near Raritan Bay they are not so 
thick, and the division line between the plastie clays and the clay marls is accurately 
located near the mouth of Cheesquake Creek. But towards the south-west the overly- 
ing drift is so deep that it is impossible to draw the Southern houndary with much 
certainty.”—Cook, Geol. Rept., 1873, p. 103. 
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