At Cherokee there is an inverted siphon of wrought iron. The pipe has an approximate inner diameter of 30 inches, discharging 52 cubic feet of water per second. It has been in continuous use for five years, and is now in first-class order. The iron used was ordinary English plate of fair quality. The greatest pressure it sustains is 887 feet, and the thickness of the iron at that point is threeeighths of an inch. The plan* on the next page taken from the original survey on file in the office of the company, shows the line of the pipe, and different sizes of iron used in construction of the siphon. The maximum strains on the several sizes of iron used are given in the following table: The Virginia City Water Company, Nevada, has constructed a similar wrought iron siphon, 11 inches in diameter. The maximum pressure in its greatest depression is 1720 feet, equal to 750 lbs. per square inch. The thickness of the iron at the lowest point of depression is No. 0. The pipe was hot-riveted, g-inch rivets, double row on straight seam and single row on round seam. This pipe, when tested, is said to have stood a pressure of 1400 lbs. per square inch.† THE SUPPLY OR FEED-PIPES. The water is conveyed to the claims in iron pipes from the pressure-box, and by means of iron distributers on the lower end of the feed-pipe it is distributed to the discharge-pipe as required. * The Mining and Scientific Press of January 7th, 1871, contains a detailed account of the construction of this pipe, and also gives a diagram of the line. + The Virginia City Water Company has constructed a second siphon, made of lap-welded pipe, 10 inches inner diameter, 2-inch iron, and placed it alongside of the siphon already built. The pressure-box should be strongly built, and the water supplied in sufficient volume to keep the top of the pipe covered several feet. A grating on the end of the flume which connects with the box prevents the entrance of foreign material, such as sticks, leaves, etc. The pipe is of uniform diameter down to the distributer, except where it enters the pressure-box. Here it swells to a funnel shape, connecting at its greatest diameter with the box. The size of the feed-pipe is determined by the head and quantity of water to be used. The thickness of the iron of which it is constructed varies with the diameter of the pipe and according to the hydrostatic pressure. As it is not desirable to alter the position of the main feed-pipe often when in place, it should descend in the most conveniently direct line into the diggings, avoiding as far as practical all angles, rises, and depressions. Air-valves with floats, or such valves as will open and close automatically, should be arranged at proper points, to allow the escape of air when filling the pipe, and also to prevent any collapse from atmospheric pressure should a vacuum occur, Where the pipe passes over steep banks into the claim, it is carried on an incline trestle, and braced, care being taken to prevent any movement or sliding of the column. When necessary, the pipe is secured with framework and weighted with stones. At the bot tom of this incline, where it reaches the bed-rock or level of the workings, it is securely braced and weighted. A distributing-box (made of cast iron into which the supply-pipe is led, and from which one or more branches can be taken as wanted by means of valves) is generally placed at this point. In some claims double distributing gates are used, in others the main pipe is here forked by means of a breeching having two branches, and a distributer placed on each branch. The branch pipes (generally 11 and 15 inches in diameter) connect directly with the discharge nozzles. The annexed sketch shows the form of a single "distributer" used in hydraulic mines. This style of distributer is also used as a discharge gate for reservoirs. In filling the feed-pipe the water should be turned on gradually, all sudden straining of the column being thus avoided. Any leakages in the slip-joints can be readily stopped with a few bags of sawdust, and by wedging them with thin pieces of soft pine. THE DISCHARGE-PIPES. The discharge-pipe most generally used is called the "Little Giant."* It is portable and easily handled, having a knuckle-joint and lateral movement. The "Giants" have stream concentrators, and the nozzles used are from 4 to 9 inches in diameter, 5 to 7-inch nozzles being those most generally in use. The number of "Giants" employed in a claim depends on its size and quantity of available water. There are generally two or three used in a claim. The annexed sketch (Fig. 1) shows the general form of the Little The Little Giant. (Hoskin's patent.) Fig. 1. Section along line c, showing the rifles. с * Other nozzles in use are the "Dictator," of Mr. Hoskins, who also invented the "Little Giant," Craig's "Globe Monitor," and the "Hydraulic Chief,” an invention of Mr. F. Fisher. Giant. Fig. 2 represents a monitor hydraulic machine with a "deflecting nozzle," the invention of Mr. Henry C. Perkins, superintendent of the North Bloomfield Gravel Mining Company. By means of the "deflecting nozzle" the Giant can be turned to any point, and the stream issuing from the pipe can be directed with the greatest facility. Its workings will be easily understood from the following explanation: B, Deflecting nozzle of wrought sheet iron, attached to A by a joint similar to a compass gimbal. C is a lever to govern the movement of B. D is a rest for lever, B. The operation is as follows: When the lever, C, is in the rest, D, the deflecting nozzle, B, allows the stream of water from nozzle, A, to pass through without obstruction. To move the pipe the lever is taken from the rest and thrust in the direction it is desired to throw the stream. Any movement of the lever, C, either to the right or left, or up or down, throws the end of the nozzle, B, into the stream of water, and the force of the water striking it changes the course of the discharge, the entire machine moving in accordance with each change of the deflector. The joint attaching B to A being a universal joint, the nozzle can be turned in any direction. STORAGE RESERVOIRS. When water is not taken from running streams, the mines are dependent for their supply on the winter rains and snows. Large reservoirs are built to catch the water from the rains and melting snows, and store it in the spring and summer months for use during the dry season. The North Bloomfield Company has established a complete system of reservoirs for the storage of water. The Bowman reservoir, and the small reservoirs about it, will hold, when the main dam is completed to a height of 96 feet 3 inches, about 1,000,000,000 cubic feet of water. The cost of the reservoirs and dam to date is $214,392.06. The Rudyard reservoir, of the Milton Company, contains 535,000,000 cubic feet of water, or 3,980,000,000 gallons. The reservoir |