70 Phosphate Rocks of South Carolina, 
come a staple article of commerce. Large ships and 
steamers are daily seeking cargoes from the Ashley, 
Stono, Wando, Ashepoo and other rivers; and the 
State is now reaping a great harvest. Over six mil- 
lions of dollars have already been invested by North- 
ern capitalists in mining and manufacturing the Rocks 
into rich fertilizers; and many persons who in 1867 
were unbelievers, have now ¢her thousands invested in 
zt. The foregoing isa simple and true history of the 
discovery and development of the Phosphate-rocks 
of South Carolina. 
THICKNESS OF THE:STRATUM Witt 
VIELD (PER 2Chis: 
Fifteen or eighteen inches may be considered the 
average thickness of the stratum of the Phosphate- 
rocks; though there are many places where it has 
been found three feet thick. Here and there a pocket 
occurs, extending several feet, and to as great a 
depth. It is safe, therefore, in making estimates of 
the yield per acre to take the lowest, that of fifteen 
inches. Should the stratum be uniform six hundred 
tons may be safely calculated upon as the yield; 
though there are many “diggings” now returning 
eight hundred and a thousand tons per acre. No 
estimate can be made for River deposits; in some 
places the rock is found in great heaps, accumulated 
by the force of currents, and then again, a few yards 
off, the river-bottom is laid bare from the same cause. 
