Recent Changes in Gold Mining 
117 
/po/] 
per hour, each machine be given 72 gallons of water per min- 
ute. This will then at times require 25 H P. for a complete 
unit of two washers and trommels. These factors will vary 
greatly with the character of the ore. Since the power, and 
therefore the wear, will increase even more rapidly than the 
square of the speed, this should be kept low. In the absence 
of any coarse stones, there is also danger that the pulp may be 
too greatly agitated to allow the settling of the gold. On the 
other hand, the speed and work must be sufficient to grind up 
the ore. If there is too little water, the clay paste may not 
allow the gold to settle. If there is too much, there is a dan- 
ger of the gold being washed out. While a large capacity is 
of advantage and desirable, still it will mean danger of insuf- 
ficient grinding, too thick pulping, or too strong a flowing of 
water. A great deal of skill and patience is, therefore, 
required in adjusting these fixtures, but when once adjusted, 
they will work satisfactorily. It is to be recommended that 
a first unit be installed and run over several months at var- 
ious speeds, capacities and amounts of water and the machine 
should be given plenty of time after each change of condition 
to adjust itself. Also, careful tests of the ore and tailings 
should be made between times. The capacity and speed 
should first be adjusted until the best result is given in reduc- 
ing the amount of gold left in the tailings so combined that 
it will not pan. The pulp should of course be kept at a reas- 
onable consistency throughout the changes and the amount 
of water finally adjusted so that the tailings will show a min- 
imum of free gold in the pan. 
These machines are made in Knoxville, Tenn., and are 
handled by Geo. L. Erdman, of Asheville, N. C. One of the 
first of these machines was installed at the Shuford Mine, 
owned by the Catawba Gold Mining Company, and situated 
about three-quarters of a mile north of the post-office of 
Edith, about 5 miles south-east of Catawba Station on the 
Southern Railway. They have a plant of 4 double units. 
The Company are operating on a tract of land containing a 
gold-bearing zone said to be 2 miles long and 600 feet wide. 
