Ch. 5: Mine & Milling Practice

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	98	GOLD MINING IK KORTH CAROLINA.

	rough sketch of the plant and method proposed. Twelve miles of ditch and flume line (1) carry the water from a reservoir, through the Dan Sisk gap in the South mountains, to a penstock (4), situated 200 feet above the level of the creek bed. The ditch is cut about 8 inches deep by 20 inches wide, at a cost of about 25 cents per rod, and is given a grade of from li to 3 inches in 100 feet. The flumes are, at ordinary grade, 18 inches wide by 12 inches deep (see fig. 10). A sill, bent, top and side brace are erected every 6 feet at the jointing point and middle of each box. The bents are made of rough lagging seldom more than 6 inches in diameter, the greatest height of trestle being less than 30 feet. The sill of the flume acts as a cap for the posts. Wherever a small grade becomes necessary, the width of the flume is doubled. The cost of erecting these flumes is small, equal to about the cost of the material in them. Lumber is worth $6 to $7 per thousand.



	The water, before reaching the penstock, flows through a sand pit (2, fig. 9), to catch sand, etc., washed into the ditch line from the side. It then enters the penstock after passing through a screen (3) for removing leaves, sticks, etc. The pipe (5) leading from penstock is 10-inch spiral riveted sheet-steel (with No. 16 Birmingham irauge), coated with coal-tar and connected with flanges. Smaller curves are made by placing cast-iron bevelled wings between the gaskets of the flanges, larger ones by suitable elbows. Near the gravel pit the 10inch pipe branches out through a Y (6) into two 7-inch pipes, supplied each with a gate-valve, one leading to the giant pen and the other to the hydraulic elevator (7). These are both of California type and manufacture.¹ An illustration of the latter in detail is given in tig. 11. The principle of this device is too well-known to require a description. It ¹ Joshua Hendey Machine Works, San Francisco, Cal.

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