54 BOARD OF AGRICULTURE. 



dred millions of tons of this valuable phosphate rock lying 

 there untouched, to say nothing of the vast number of tons 

 that have been ground up by the action of the elements 

 through untold ages, and filtered down through the underly- 

 ing strata of marl, as appears evident from the large percent- 

 age of phosphoric acid — from six to ten per cent. — in the 

 composition of the upper strata of this marl. The supply is, 

 therefore, practically inexhaustible, and so rich in phosphate 

 of lime as to furnish a basis for the manufacture of super- 

 phosphate, even better than fresh bones. 



It will readily be understood, from the descripton of these 

 phosphatic strata, that the process of mining is very simple 

 and comparatively easy. A trench is dug and the nodules 

 picked out or loosened with a common pick ; in this crude 

 form, covered with the mud and clay adhering to them, they 

 are thrown into a cart or upon simple tramway or dump-cars, 

 and run to the bank of the river, where they are thrown into 

 large revolving cylinders and washed with a stream of water 

 poured upon them, and so freed from the clay and mud at- 

 tached to them, when they are ready to be ground. Any vessel 

 that can cross the Charleston bar can go up the river and load 

 along the banks. I saw thousands of tons of these phosphate 

 rocks that had been dug out, washed and piled up along the 

 river-banks ready for shipment. In this crude form they are 

 estimated at about seven or eight dollars per ton. 



The stratum of phosphate rock underlies the river-beds, as 

 well as the adjacent lands, though it may not be so uniform 

 in thickness, owing to the action of the currents. The negro, 

 who does not take particularly to the pick and spade, began 

 to fish for the rock with a rude kind of grapnel or tongs, and 

 he could raise enough in a day to supply his simple wants, 

 even in this rude way. This suggested a more complete sys- 

 tem of operations, and led to the formation of a company 

 called the "River and Marine Mining Company," chartered by 

 the legislature, with an exclusive right to take the rock from 

 beneath the waters of the State for twenty years, paying a 

 royalty of a dollar a ton into the state treasury. After great 

 expenditures in experimenting, they have powerful machinery, 

 worked by steam, in successful operation, and capable of rais- 

 ing and washing several hundred tons a day. The process is 



