TERRA-COTTA, BRICK, ETC. 
131 
He observes that the clay pits about South Amboy furnish 
a large amount of this useful substance every year, and that 
the market is continually widening. It sold for from $1.50 
to $5.00 per ton. Any needed amount of clay can be had 
from the pits along the Delaware and its branches. Clay 
suitable for making water-pipes is dug near the Woodmansie 
Station on the Raritan and Delaware Bay Railway. Light 
colored clays of the tertiary formation are found at many 
points in the Southern part of the State, suitable for making a 
common quality of fire-brick and for other purposes. 
Coarse clays, superior to brick clays, occur in inexhaustible 
quantities over and under the fire-clays. They are well 
adapted to the manufacture of coarse pottery, sewer-pipes, 
drain-tiles, etc., for which they are already, to some extent, 
utilized. 
For the manufacture of glass-pots, which require a pecu- 
liar and excellent quality of clay, it was formerly thought 
that none of a suitable composition existed in the United 
States, and that only English and German clays could be 
relied upon. Experiments were made at Wheeling, Vir 
ginia, on clays obtained at the Mt. Savage Iron Works, 
and the measure of success attained encouraged the belief 
that the glass-works might become independent of foreign 
sources for this material. Soon after, a clay was obtained 
from Missouri which proved to be equal to, if not superior, 
to any other known clays for such purposes. 
The fire-clays of St. Louis, according to Dr. Litton, 
have the following composition :— 
1.» 
3.t 
Silica, 
Alu min 
Oxide of iron, 
Lime, 
Magnesia, 
Potash, 
Soda, 
Sulplmr, 
Water, 
61.02 
25.64 
1.70 
.70 
.08 
.48 
.25 
.45 
10.00 
59.60 
26.41 
1.61 
1.00 
.07 
.29 
.16 
.38 
10.36 
* Raw clay. 
f Preparcd, probably wasbed.