54 



The Phosphates of America. 



counters one or more heavy streams of water, pumped up by a steam- 

 pump. This water does not run off at the bottom, but overflows 

 at the higher end near where it enters. When sufficiently washed, 

 the material is pushed out upon a half-inch-mesh screen ; the small 

 debris being received on oscillating wire tables below. 



The phosphate is now ready for kilning or drying, and of all the 

 methods hitherto adopted for this important process, that of simple 

 roasting in an ordinary kiln, such as is generally used in the manu- 

 facture of bricks, is said to have been found at once the most rapid, 

 effective and economical. 



The rock is built on layers of pine wood, and owing to its con- 

 taining a considerable quantity of organic matter, it readily lends 

 itself to combustion and requires but a short time to become quite 

 red-hot. 



The kilns are made sufficiently large and are so arranged as to 

 allow free passage to a train of cars, which, running on the main 

 .line of railroad, can be loaded in the kiln, run down to the landing 

 place and discharged directly into the barges or boats on the river. 



Since the beginning of operations in 18G8, the yearly quantities of 

 phosphate taken from the South Carolina rivers and mines have been: 



Year. Land Rock. 



1868-70 18,000 . , 



1871 33,000 .. 



1872 38,000 . . 



1873 45,000 .. 



1874 43,000 .. 



1875 48,000 .. 



1876 54,000 . , 



1877 39,000 . . 



1878 113,000 ., 



1879 102,000 . . 



1880 125,000 .. 



1881 141,000 .. 



1882 190,000 .. 



1883 226,000 . . 



1884 258,000 . . 



1885 224,000 .. 



1886 294,000 . , 



1887 230,000 . . 



1888 260,000 .. 



1889 250,000 . , 



1890 300,000 . . 



Totals, 



3,031,000 



River Rock. 



. 1,989 .. 



. 17,655 .. 



. 22,502 .. 



45,777 .. 



. 57,716 .. 



. 67,969 .. 



. 81,912 .. 



. 126,569 .. 



. 97,700 .. 



. 98,586 .. 



. 65,162 . . 



. 124,541 .. 



. 140,772 .. 



. 129,318 .. 



. 151,243 .. 



, 171,671 .. 



. 191,194 .. 



. 202,757 .. 



. 190,274 .. 



. 212,101 .. 



. 237,149 . . 



2,434,557 



Total Tons. 

 .... 19,989 



50,655 



.... 60,502 



90,777 



100,716 



.... 115,969 



135,912 



165,569 



210,700 



200,586 



190,162 



.... 265,541 

 .... 330,772 

 .... 355,318 

 . . . . 409,243 

 .... 395,671 

 . . . . 485,194 

 . . . . 432,757 

 .... 450,274 

 .... 462,101 

 537,149 



5,465,557 



1891, estimated total from all sources. 650,000 



