THE MTNTNG PRACTICE-----CRAWF0KD MINE. 93
erty being at that time a portion of the W. S. Ingrain farm. For two years it was worked spasmodically by tributors, and 16 to 17 pounds of nuggets were obtained. In 1894 the property was bought by the Crawford Mining Company of New York, and was put under the able management of Mr. Kichard Eames, Jr., of Salisbury, X. C. A sketch of the method of working which was being pursued in 1895 is given in fig- 6.
The bottom having insufficient grade to carry off the tailings with the limited amount of water at hand, a washing tank and sluice were put up on the side hill at an elevation of about 30 feet above the creek. The deposit was mined by a system of parallel trenches 12 feet wide, worked from the lower end of the deposit upward. Track was laid in these as they advanced. The upper 6 to 18 inches of the over-lay were thrown off, the remaining 1-| to 2 feet, together with the true grit (gravel) and 6 to 12 inches of the bed-rock, were shovelled into cars holding about half a cubic yard. These were trammed to the foot of the inclined plane (8), and hoisted to the top of the washing plant by a small friction-drum engine (3) (see fig. 6). This tank was built of plank and is about 50 feet long, 18 feet wide and 6 feet high. On one of the sides there is a door or opening 4 feet wide, reaching to within 4 inches of the bottom to a sill. The grit was dumped into the tank and a constant stream of water kept flowing over it. The action of this stream was reinforced by water played on the material from a hose nozzle under a head of 30 feet. This head was obtained from a stand-pipe (4) to which water was pumped from a reservoir (1) by means of a Hall duplex pump (2) with a 4-inch discharge. Excepting at the time of the clean-up, the tank was kept nearly full of gravel, and under the combined action of the two streams of water, closely imitating natural agencies, a very good concentration of the coarser nuggets was attained in the tank. The material, partly assisted with a rake, flowed over a grizzly (6), the bars of which were set 1-J inches apart. The coarser pebbles and boulders were forked off, while the finer gravel and sand were carried down into a sluice (7) situated below the grizzly. The sluice was 400 feet long, 12 inches wide and 10 inches deep, and had an inclination of 6 inches in 10 feet. It contained only about 20 feet of riffles, and these were situated about 100 feet below the grizzly. Originally, the whole sluice was filled with riffles, but these were removed when it was recognized that they were superfluous for saving gold. The first hundred feet of the sluice were found to aid in thoroughly washing and disintegrating the material before it reached the riffles, and gold was seldom found below the first four or five feet of the riffles. The upper riffles consisted of diagonal slots cut in 2-inch plank, which was laid in the bottom of the sluice. The lower riffles were of the longitudinal variety (see fig. 8).
