Mr. Eames carried on some laboratory experiments in 1892 for a cyanide treatment of the Gold Hill ores, and obtained an extraction of 60 per cent, on 100 pounds treated. During the summer of 1895 Mr. Bloomer, of London, experimented with cyanide, but with what result is not known. Chlorination of the Gold Hill ores has been advised but never carried out. Xo earnest attempts have been made to treat the sulphurets on a working scale. Plate YI shows the Eames stamp-mill.
For the past number of years the only work at Gold Hill has been done by tributors, who cart the decomposed material from the old mine dumps to the Earnhardt mill, receiving 50 per cent, of the yield. This material mills about $1.50 per ton. The pulp from the stamps flows directly over a line of blankets 24 inches wide, which are washed every 20 minutes in a tank; and the concentrates are treated in a series of hollowed log-rockers, 12 to 14 feet long, provided with quicksilver riffles (see Plate I, p. 30), the tailings flowing off into the creek.
At the Isenhour mine (Cabarrus county), li miles southwest from Gold Hill, the ores from a 3-foot vein were ground (during the summer of 1895) in a Howland pulverizer of 6 tons capacity per 24 hours. The pulp was run over blankets, the washings from which were treated in rockers, as at the Barnhardt mill, with a yield of about $2 from ores that assayed from $5 to $7 per ton.
The Gold Knob mine is some 5 miles northwest of Gold Hill in the same general zone of schists. As many as 11 separate parallel ore-leads have been explored. Of these, the Holtshauser vein was again opened during the summer of 1895.
The Dutch Creek mines are in the vicinity of Gold Knob. It is stated that there are 20 veins on the property, some of which are copperbearing. The strike of the veins is generally northeast; but there is a second system striking more northerly and intersecting the first. The more or less oxidized surface ores have been largely worked out down to the water-level, below which point the sulphurets remain practically unchanged.
The Atlas and Bame mines are on the southwest extension of the Dutch Creek veins.
MIXES IN CABARRUS COUNTY.
The metamorphic schists occupy a narrow strip along the eastern edge of the county, in which are located a series of mines which might be considered an extension of the Gold Hill zone. Such are the AVidenhouse, Xugget (Biggers), Eva Eurr, Allen Furr, Rocky River. Buffalo, Reed and Phoenix.
The other mines of the county are situated in the granitic rooks near Concord and to the southeast and south of Concord. Such are the Joel Reed, Montgomery, Quaker City, Tucker and Pioneer Mills mines.
