TILE MIKING AXD MIIXIXG PEACTICE. 107
two lines of sluice-boxes, each 3 feet wide and 18 inches high, running the full length of the barge, and filled with longitudinal riffles, made up in five-foot racks, composed of 1 by 3-inch slats set 1 inch apart. The gravel is discharged from the shovel on an iron-shod platform at the head of these boxes, where the boulders and larger pebbles are removed. The gold is caught almost entirely in the upper two racks; the tailings run off into the river in the back of the boat. When in favorable ground, the dredge will scoop and deliver an average of 1 bucket every 2 minutes. AVhen examined there were 3 men on the dredge-boat, engineer, fireman and eraneman, and 6 men at the sluice-boxes. "Work is carried forward up stream, the scow being moved against the current by anchoring the scoop and pulling the scow towards it by means of the crane engine. The main wear and tear are on the lip of the scoop, and on the chains. A steel lip 12 inches in length wears out in about six months. The river ground is leased on a royalty of from 5 to 10 per cent, by the property owners. It is said that gravel as low as 5 cents per cubic yard can be worked at a profit.
In the spring of 189G a boat, equipped with a Marion Steam Shovel Company's dredging outfit, was in operation under the management of Messrs. Benliam and Heliner. A pontoon alongside of the dredge carried a line of sluice-boxes. The material from the dredge was dumped on a grizzly at the head of the sluice line and washed down by a stream of water from a Xo. 8 Held and Cisco centrifugal pump having a capacity of 1500 gallons per minute. The sluice-boxes were 70 feet in length, 61 inches wide and 12 inches deep, and provided with riffles. There was a device for carrying back the tailings and depositing them in the excavation behind the machine. The efficiency of the dredge was stated to be S00 to 1200 cubic yards per 10 hours. The expenses were estimated at about $18 per day, and the gross returns at $10 to $120 per day.
THE DAHLONEGA METHOD, WITH SPECIAL DESCRIPTION OP THE HEDWIG MINE.
The Dahlonega method of mining and milling is one which is particularly adapted to the large bodies of low-grade auriferous saprolitic schists, such as exist in the Dahlonega district of Georgia. It consists in cutting down the soft, decomposed ore-bodies by means of a hydraulic giant, the water from which carries the material through a line of sluices to the mill situated some distance below the workings, usually on the banks of a stream from which it derives its water-power. In the mill the coarser and heavier portions are retained by means of a screen, and are fed to the batterv bv hand, the mud and fine silt being; carried through into the river. Generally, a third of the gold saved is caught
