San Marcos free press. [volume] (San Marcos, Tex.) 1877-1892, 1883-02-22
so,,h Carolina Phosphates.

narOlina. Inns "0Po'A'' "A'0'' ''i -
i"rge a source OF revenue to the
s Si and TO the mining of which
gag o. saa Islands to q great extent owe
@ NV rresent prosperity, extends from
~. cooper river on the North, to the
SS'osG rIyer on the South. The tract of
,'Nd and water supposed to be under
i';J by the phosphate stratum, is
nv Lout 100 miles long and 25 miles
,";SO. Originally all this tract was
'ndsr water, and the islands were
iaurmed by the slow growth of sand
Rors and gradual elevation of the
sonntry. The phosphate rock lies
IN A led of clay, not in solid sheet,
INIT much rs the paving stones in the
sondbed of the city's streets. The stra-
INN is of an average depth of one foot,
An acre will yield 1000 tons Of dried
nhosphate rock fit for the market.
n rivers and shallow bays the stra-
nm is generally covered by thin
LAYER of sand or muck, and many tons
If loose rocks are scattered widely On
tbe almost solid surface of the main
deposit. In the marshes the rock is
covered by from three to twenty feet
Of muck, and under the islands it is
deeply covered by sand and gravel.
Il is only such rock that lies under
tbe water, or is carried by shallow
deposit ofmuck on the marshy ground
that is worked at present. The pro
cess of obtaining this rock is called
mining, but when it is under water
it is more properly fishing, as from
eight to twenty feet of water cover
the stratum at high tide. tits supposed
that the clay bed on which the phos-
phate rock lies was pasture ground
for large mastodons that roamed at
will to and fro over the marshy
ground as the tide ebbed
and flowed. The fossil remains OF
sharks, CLAIMS, oysters and mastodons
are scattered throughout the phos-
phate formation.
Northern capital developed the
mines OF rock fisheries. It is due to
Northern and English capital and
enterprise that this industry, yet in
its infancy, exists. There are var
GUS methods of obtaining the rock.
Little scows, capable Of taking ten tons,
manned by a negro crew, have been
greatly employed in the past and are
still used. These scoWs are rowed or
pulled to the selected spot and there
anchored. The negroes using long
handled tongs similar to oyster tongs
only heavier and stronger fish for the
phosphate rock as though longing for
oysters. They are able to obtain such
pieces of rock as may have been bro
ken loose by the strong currents con-
stantly whirling in Underwater rivers,
and occasionally they can detach
pieces from the unbroken pavement.
They are paid from $50 to 81 per
ton for the undried rock delivered Oh
the dock Of the company employing
them. A ton of undried rock weighs
$500 pounds. 1t can be readily seen
that this method of longing up loose
bits Of rocks and trying to detach
other pieces from the MAIN pavement,
when they were covered by sixteen
feet of water, would not be long pur-
sued. Lighters were lost, tongS were
broken, and though roughly made,
they are covered by patents and are
actually expensive tools. Various
mechanical devices were tried, some
of them exceedingly expensive, with
different degrees Of success and failure.
The most of these devices were cum
ming notifications of thedredges used
in Northern harbors to deepen chan
nels. The main difference was III
strengthening and increasing the
weight of the dippor, and applying
the power a little differently so as to
make the motion q prying instead OF
a scooping one, and in the employ
ment of more powerful machinery;
This modified dredge works well, and
is by many of the phosphate fishers
considered the best device yet invent
ed. The barge carrying this dippel
is strong and heavily timbeTad. Ii
is anchored from the bow and stern
When all rock within reach Of the
dipper has been scooped up, the an
chor lines are, loosened and the barge
floats upor down with the tide. Ths
desired position reached, the lines are
frightened: the scooplng IS resumed
and when all the rock within reach
of tie long wide-sweeping arm mas
been dipped up, the barge is AGAIN
allowed to drift with the tide TO IN
scooDed oround,