120 Journal of thf Mitchell Society [. November 
from a small settling 1 pond nearby. In order to get sufficient 
fall for the head and tail sluices, the machines are put pretty 
high up on the hill so that a fat incline has been put in with 
dumping arrangements, etc. similarly as at the Shuford Mine. 
The ore is broken up by hand into about 3 inch cubes and 
when not hard, there is some tendency for it to stick in the 
grizzly crusher owing to the large percentage of clay, which 
is often moist. The first machine is run as high as 250 revo- 
lutions per minute on hard rock, but was found to give best 
results on average partly decomposed slates at 175 revolutions 
per minute. As there is no hard quartz in this ore, there is 
no need of an intermediate trommel. The second machine is 
operated at only 90 revolutions per minute and saves most of 
the gold, which is very fine. The trommel which follows 
this washer removes practically nothing but fragments of 
tree roots, which shows that everything is ground below 
4-mesh. The riffles are 64 feet long, but very little gold is 
found below the first 20 feet. With this soft, clayey ore the 
capacity is about 8 tons per hour and 110 gallons of water 
per minute are required. In the summer of 1906 the machine 
had hardly passed the experimental stage, but the tailings 
almost never showed any free gold and assays of carefully 
taken samples showed a recovery of 90 per cent of the soft 
material and 80 per cent on the hard. 
A few modifications of the machine have been made by Mr. 
O. K. McCutcheon, Superintendent of the Empire Company, 
by introducing an improved stuffing box and valve for the 
clean-up openings and in the second washer iustalling a plate 
9 inches wide and one inch above the center of the bottom 
with cross-lots ^ inch by 5 inches. This false bottom is 
curled up at the discharge end and serves as a riffle plate, 
thus considerably increasing the recover} 7 of very fine gold. 
One double unit of these machines was being worked on 
the property of the Troy Mining Co., 7 miles north of Troy, 
Montgomery County. There are some old shafts, but the 
two main workings are based upon recent discoveries. By 
test pits and panning it seems there are two parallel zones of 
