eclipse every other branch of mining industry. The principal cause of this success, and the energy displayed by miners of this class, is attributable to the recent improvements made in apparatus or machinery, long needed, which would enable the miner to use a heavy, perpendiculary pressure of water with safety and economy, and at the same time place it within the power of a single operator to concentrate in one stream and effectually control a large body of water.

To fully understand the extent of these improvements, it will be necessary to state a few facts in relation to the primitive or old-fashioned method of conducting this work, and trace it step by step to its present perfect condition.

The object to be accomplished is to confine a body of water in a compact, continuous stream, to a certain point of egress, whence it will pass, with more or less force, in an almost solid column. This force will, of course, be governed by the relative height of the entering head of water above the discharge-pipe or nozzle. The stream so obtained is used to undermine banks or walls of auriferous dirt and cemented gravel deposits, and the greater the height or elevation at the point of supply, the greater will be the force and quantity of the water discharged; and the more those two powers (fall and quantity) are concentrated, the greater the amount of earth that will be torn down and removed, resulting in a proportionately larger yield of the precious metals. Having thus described the object, I will now speak of the apparatus used for bringing about these results.

Canvas hose was first brought into general use in 1853, and as the larger proportion of the mines worked at that time were quite shallow, and the dirt, as a general thing, soft, it was found to answer so well that several years elapsed before an effort was made to improve on it. Canvas hose is constructed about six inches in diameter, of very strong sail-cloth; will bear with safety from eighty to one hundred feet pressure, and discharge effectually a stream of water one, and three-fourths or two inches in diameter. The material, however, which is composed of cotton, is very expensive, and rots rapidly, while, at the same time, it is ever liable to burst by the weight of water, and thus become a com plete loss to the miner.

As the development of gravel deposits progressed, it was found that the materials of a large proportion of our richest mines were very difficult to disintegrate. These consist of a species of cement, and the working of the gravel beds demonstrated that greater fall or pressure was needed to enable the water to undermine and break up the gravel; and as canvas hose could not bear the necessary pressure, a substitute was found in sheet-iron pipe. This is constructed of various dimensions, from six to forty inches in diameter; but, in order to obtain a flexible discharge piece, it was necessary to retain a short piece of canvas hose, and in order to make it safe it had to be covered or bound up by a netting or cover of strong rope, which was both expensive and inconvenient. These difficulties combined succeeded in arousing the inventive ingenuity of the miners, and resulted in bringing to light the inventions known as the "improved hydraulic nozzles," the first of which was invented by the Messrs. Craig, of Nevada County-a county which has had the honor of inaugurating all the improvements in this branch of mining. These improved nozzles proved a complete substitute for canvas hose, and by their simplicity of construction, cheapness, and durability, met with an immediate, rapid, and extensive adoption by the miners throughout the State. This has enabled them to use with safety a sufficient head of water to work the hardest dirt or gravel rapidly and

cheaply, and at the same time to use a pipe of any size required, so as to run all their water in one stream, which alone nearly doubles its ef fectiveness, and besides places it under the control of a single operator. They gain in force, saving manual labor, and economizing in every way. I will briefly describe two of these inventions:

Craig's Globe monitor or Globe hydraulic nozzle.-This invention consists of a hollow ball or globe, with an opening at one side, into which

Craig's Globe Monitor.

enters the main feed or supply pipe, and one on top, out of which protrudes an elbow joint. One end of this elbow is attached to a socket, which revolves on the interior of the globe, and at the same time creates a water-tight joint; this joint enables the operator to change the direc tion of the stream from point to point at pleasure. To the other end of the elbow is attached the discharge-pipe, which may be of any size desired. The ball revolves entirely round horizontally, and up or down, at an angle of about forty degrees. This play has been found amply sufficient for all ordinary mining purposes, and causes a perfect stream to emerge at any point to which the nozzle may be directed. As a mat. ter of economy, it not only places the water of seven or eight ordinary hose-pipes under the control of one man, but its durability is so great (one lasting a life-time) that its extra first cost is seldom noticed, it being in convenience alone worth more to the miner than the difference of cost of canvas hose. No canvas being used, it is not liable to breakage under heavy pressure, and saves the annual outlay for canvas, while the concentration of a larger body of water in one column has been found to nearly double the amount of execution in comparison with ordinary expenses. The proprietors, Messrs. R. R. & J. Craig, of Nevada City, manufacture four different sizes, the largest of which will run some 1,500 inches water, "miners' measure."* The Messrs. Craig have three United States patents upon the monitor and its improvements, and deserve great credit for developing so valuable an auxiliary to our mining industry.

*A "miners' inch" of water is generally accepted to mean the quantity of water which would flow from an aperture of one square inch, under the pressure of a steady flow of water standing six inches above the top of the escape aperture; consequently 1,000 inches of water (the amount now thrown through a 6-inch nozzle) is the quantity which escapes at the discharge-box from an aperture or gate 6 feet in length and 14 inches in height, under a pressure of 6 inches of water above the top of the aperture. The discharge-boxes are generally 6 feet by 6 feet, and 2 feet in height. The difference of elevation between the discharge-boxes and the "distributor" (from which the water is conveyed to the nozzle) is generally 200 feet or more-at Gold Run nearly 300

feet.

F. H. Fisher's knuckle joint and nozzle.-This machine consists of two elbows placed in reversed position when standing in right line, but made to revolve by a

ring in which there is a series of anti-friction rolls, the ring being slipped down over the top of the lower elbow and then held in its place by a flange, bolted to the top of the lower elbow. The ring is then bolted to a flange on the top elbow, thereby

convex one;

connecting the two together and at the same time leaving the top elbow free to move around in a complete circle. When the water is let into the elbow the pressure brings the rolls up in the ring against the flange on top of the bottom elbow, allowing the top elbow to move around easily and without any friction except that of the rolls themselves. A piece of rubber packing placed between the flanges of bottom and top elbows, makes the joint tight by the pressure of the water against the ring. In the outlet or top elbow is a knuckle joint which gives the up and down motion to the discharge-pipe. It is a concave surface fitted to a the concave has an opening for the pipe to pass through. The pipe is screwed into the convex surface and will move up and down while the concave one is bolted firmly to the flange on the top elbow. The elbow and knuckle joint are made of cast iron from 3 to 3 inch thick. The discharge-pipe is made of No. 16 iron, 8 feet long, with castiron nozzle. The machine is operated by a lever 10 or 12 feet long with two arms, and attached to top elbow by trunnions. A lever is pivoted to the top of the upper elbow and attached on one end to the discharge-pipe by a strap inclosing the pipe and provided with two rolls on top for the lever to slip on. At the other end it is connected with the operating lever by a short upright lever made to work loose in its joints. Thus the up and down motion is imparted to the discharge-pipe by the rise and fall of the operating lever. By moving it to the right or left the whole machine except the bottom elbow is moved. A little device is attached to the lever to hold the discharge pipe in position when the water is off. It is a catch working in a ratchet on the top elbow, attached by a rod running out on the lever so that the operator can put it in or out as the case may be. The pipe stands firmly in place when the water is on; the operator standing at the end of the lever can easily direct the stream to any point-good execution being done at a distance of 200 feet from the bank, thus securing safety of life from caves which are of so frequent occurrence and often fatal where small streams are used against high banks. These machines are made to throw streams of from 4 to 7 inches in diameter, and were invented by a citizen of Nevada County, Mr. F. H. Fisher.

ROCK-DRILLING MACHINES.

Besides the improvements in hydraulic machinery many other mechanical discoveries and improvements have been made during the past year, resulting in a large aggregate of practical benefits. Among these may mention:

I

The Blatchley rock drill.-This machine, invented by Dr. Blatchley, H. Ex. 10- -5

of San Francisco, and constructed at the Miners' Foundry, has only recently been brought to perfection, after four years of continuous and costly trial, during which every alteration and addition was made that the severest practical tests could suggest to the mind of the orig inator. A machine capable of doing work of this kind with expedition and economy has long been a desideratum in the mining regions, where we have so many tunnels to drive, and often through the hardest material. The Blatchley drill is an exceedingly powerful implement, and at the same time simple, inexpensive, and durable. It is but 30 inches long, 7 wide, and 10 high; weighing only about 100 pounds, apart from the drill, which is inserted after the machine is in position. It can be operated by hand, so little power is required to drive it. It can be attached to an engine or other motor at a distance, and the method of using it can be easily learned. For ordinary work it gives 300 blows, cutting 3 inches in granite, per minute, though this rate of speed and execution can be doubled with a corresponding increase of power. ingenious method of transmitting power from the surface into the mine or tunnel below, insuring the running of many machines at small cost, 'has just been completed and patented by Dr. Blatchley.

An

Diamond-pointed steam drills, their application to mining operations in California. These machines were first introduced on this coast by Sev erance, Holt & Co., in the early part of 1870, and used on Telegraph Hill, San Francisco, where holes were bored two inches in diameter and from 20 to 35 feet deep, for blasting purposes. These holes were made merely to show what the machines could do, and were bored 20 feet in from three to four hours; and 35 feet in less than six hours. The contractor, who was taking out the rock for the San Francisco bulkhead, and making holes of a corresponding depth, same size at the bottom, but much larger at the top, with hand-power, on the old-fashioned "churn". drilling process, employed six men from twenty to twenty-five days to bore a single hole the same depth, at a cost of over $10 per foot. The machines were worked by two men, an engineer and fireman. The boles made by the "diamond drill" are perfectly round and of a uniform size, which makes them much more effective than those made by the old process. The contractor claimed that the amount of rock displaced by a blast put in one of those holes was eight or ten times greater than by the old system of drilling. Holes were made 3 feet deep in seven minutes.

The first deep boring done near San Francisco was at Mission Creek, through the same character of rock, for an artesian well. This hole was made 327 feet deep, and 3 inches in diameter.

In Tuolumne County the company bored prospecting holes near Don Pedro Bar and Tuttletown. At the latter place Messrs. Gould & Cooper bored seven perpendicular holes through talcose slate, porphyry, and sandstone, and cores were taken out showing the character of rock. The diamond drill made from 10 to 35 feet per day of ten hours. The holes were made from 30 to 157 feet deep.

At Carson's Hill, Calaveras County, the company used a machine on the "Union Mine," prospecting for the direction and value of the different leads. These holes were made from 120 to 317 feet in depth. The rock bored through was slate mixed with quartz. These holes were all bored at an angle of about 45°, and the machine made as high as 70 feet in a single day of ten hours, through slate with quartz streaks through it. In five hours 13 feet of white crystal quartz was bored. This was the hardest rock found in the mining districts.

Near San Rafael, in Marin County, on the premises of Mr. George

Worn, the company bored several holes 24 inches in diameter and from 100 to 300 feet deep, for artesian wells. The rock here was of a very peculiar character, and generally very hard. It changed very often from sandstone, hard and close-grained, to a conglomerate of slate, volcanic rocks, flint and basalt mixed. This boring was very difficult, nevertheless the machine made as high as 24 feet in six hours.

The company have machines at the Pacheco Mine, Monterey County, for prospecting purposes, and in various other places in the State; also one in the White Pine district, and are constructing one to be run by compressed air for the Blue Gravel Mining Company of Smartsville, Yuba County, California, a description of which will be found under the heading of "The Smartsville Hydraulic Mines." Should this machine prove a success in point of execution and economy-and recent experiments at Smartsville leave no doubt on that subject-we may reasonably expect the construction of many extensive drain tunnels in California, which were formerly considered impracticable on account of the

expense.

These tunneling machines are made to suit the size of any tunnel, as per order. The compressors required to run one of these machines in a long tunnel are arranged to work by any power convenient, and do the double duty of working the drilling machine and ventilating the tunnel at the same time. Most of these machines are made to run by steam, but those for tunnels, shafts, stopes, &c., are intended to have compressed air for the motive-power. Prospecting machines with horizontal boilers on wheels are constructed which can be used to bore prospecting holes 1,000 feet, if necessary, taking out a core the entire depth, and having sufficient power to lift the refuse matter out of a shaft, or do any work in which strong power is required, without disturbing the progress of the drill in the least.

The Von Schmidt diamond borer.-Colonel A. W. Von Schmidt, of San Francisco has invented and is now constructing a drilling machine, or, more accurately speaking, a tunnel borer, which unites all the excellent qualities of the diamond drill with many novel features which promise to make it a greater success than any machine now in use for driving tunnels. The inventor considered that the great obstacle to rapid progress in running tunnels has been the resistance offered to blasts in a solid face of rock, and for the purpose of overcoming this difficulty has constructed a machine which will cut a circular slot in the face of the tunnel, 24 feet in circumference, 2 inches in width, and 3 feet in depth. At the same time a blast-hole, 2 inches in diameter and of same depth, (3 feet,) will be bored in the center of the face of the rock. The face of the tunnel now presents the appearance of a huge grindstone, set up on edge, and attached on one side to the solid rock out of which it is cut. The blast is put in the center hole, and the resistance of the sides having been overcome by the cutting of the circular slot, a single blast will take out rock to the depth of the slot or cutting on the sides. The machine, which has been drawn back while the blast is discharged, is now advanced against the face, when another slot is cut with like results. Allowing a reasonable time for firing the blast and clearing up the débris, the machine is expected to cut a smooth tunnel, 8 feet in diameter, at the rate of 14 feet per day. The cutting will be done by twenty-four diamond drills revolving on the periphery of a cylinder 8 feet in diameter, at the rate of eight hundred revolutions per minute, while the cylinder itself revolves once in a minute. The drills are set in motion by a disk at the back of the cylinder. The machine will be run by compressed air, and is intended to cut the tunnel of the Lake