THE PKOCESS OF MINING. 55 



simple and effective. On the Stono River, about fifteen miles 

 from Charleston, the company uses four flat-boats, of about 

 a hundred tons each, lashed together side by side, and moored, 

 so that the position of each can be readily changed. The 

 boat on the right carries the coal for use in the engines, and 

 when the load is used up this boat is carried around to the 

 other side to receive the rock. The next boat carries the 

 engine and the apparatus used to operate the steam-shovel or 

 dredge, which takes up from the bed of the river and deposits 

 in the third boat something like three cubic feet of the phos- 

 phate rock, clay, mud and sand at each dip. On the third 

 boat there is a small steam-engine also, for operating a force- 

 pump, to be used in raising water for washing the material, 

 which is dumped into two hoppers alternately, where a con- 

 stant stream of water is poured upon it, which washes it com- 

 pletely, when it is deposited on the next boat as fast as two 

 men can shovel it away. In this way fifteen hands can raise 

 and clean from seventy-five to a hundred tons a day of ten 

 hours. The same company has another establishment near 

 by, and still another on the Bull River, about forty miles from 

 Charleston, said to be capable of preparing for market several 

 hundred tons a day. Here the rock is in a continuous and 

 unbroken layer, which has to be crushed before it is 

 washed. 



When the value of the material first became known, lands 

 in the vicinity of Charleston were held at a very low figure. 

 Everything was prostrate there, and lands could be bought 

 in any quantity at from two dollars to ten dollars an acre. 

 Enterprising fertilizer manufacturers, who foresaw their oppor- 

 tunity, soon purchased largely, and the price very rapidly 

 advanced. A plantation, owned by a widow, that had been 

 valued before this at about six thousand dollars, was bought by 

 the Charleston Mining and Manufacturing Company for forty- 

 five thousand dollars, and was afterwards estimated to be worth 

 five hundred thousand dollars, and sales were made to other 

 parties at a thousand dollars per acre. It therefore became 

 an object of importance to secure the rich deposits in the beds 

 of the rivers. 



As to the composition of the phosphate rock and its com- 

 parison with bone phosphate of lime, it may serve to explain 



