bars of which are set 5 inches apart. The coarser material passes over the grizzly and on to the platform and bin below, from which it is loaded into cars and run out. What goes through the grizzly drops into a hopper below, from which it is fed into the flume.

This flume is 14 inches wide and 18 inches deep. It has a grade of 5 inches in 12 feet, and we run about 130 inches of water in it. This water carries all the material that comes into the flume out of the tunnel, and dumps it into a dump-box.

The dump-box is a large double compartment box, each compartment being 35 feet by 12, and 9 feet in the clear. It is provided with a large movable "tom-iron," and two hydraulic nozzles working under 90 feet pressure. The mine is worked on the day shift only, the quartz and dirt being run into one compartment of the box. The dump-box is run on the night shift, when the material that comes in by day is thoroughly washed free from clay, and is then run into another set of sluices, which convey the quartz direct to the mills.

At the mills the quartz-sand and dirty water are passed over a long grizzly of perforated screens. The quartz drops from this directly into the ore bins, and the sand and dirty water passes through the screens and is dropped into another flume. As the quartz goes into the mills it is also separated automatically as to size-the finer part going to the stamp mill, and the coarser to the concentrating mill. The waste water and sand that goes through the grizzlies is taken by the flume below to what is called the plate house," where it is distributed over silvered plates.

We mine on week days only, running the mills every day. In every working day we mine about 300 tons of material. Of this about 10 per cent is run out in cars, and 90 per cent comes out in the flumes. This material is largely clay and sand, too fine to pay for further crushing. Three hundred tons of this dirt will produce 95 tons of milling quartz. This loose material—the sand and clay-all carries a considerable amount of fine loose gold, varying in size from the finer float gold up to particles the size of the head of a pin-we never find any coarser than this. This gold we save in the sluices and plate house. For this purpose we have the following arrangement of flumes, etc.: The flume from the chamber to the dump-box is 800 feet in length; grade, 5 inches in 12 feet; width, 14 inches, and is lined with block-riffles the entire way. The flume from the dump-box to mills is 300 feet long; grade, 6 inches in 12 feet; width, 24 inches, and is also lined with block-riffles. From the mills to the plate house the flume is 300 feet long; grade, 6 inches in 12 feet; width, 24 inches, and is lined with slat-riffles. These various flumes pick up about all the visible gold, so that the material that goes into the plate house is apparently nothing but sand and dirty water.

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In the plate house this sand and water is divided into 6 equal parts, dropped into distributing boxes, and run over 6 aprons. These aprons are 20 feet long by 9 feet wide, with a grade of 5 inches in the 20 feet of length. Near the lower end each apron is covered with an apron of silvered plates, 9 feet square; below the silvered plates is a riffle filled with mercury, catch loose amalgam, and below the aprons is a tank into which everything drops, to catch the loose mercury. All the water and sand is run over these aprons, each carrying about 20 inches of water. These aprons save the float gold that has escaped the sluices, and sometimes give astonishing results. We have cleaned up as high as 160 ounces of amalgam from them in a week. This gold is of the finest possible sort, and the amalgam has absolutely no grit, and is apparently almost a homogeneous

mass of hardened mercury. The water, after leaving these plates, goes to waste, the plate house being the last gold-saving apparatus we employ.

At present we are working only the main vein. A great amount of work, however, has been done on the side veins, and a number of promising bodies of high grade ore have been developed. These side-vein ore bodies vary in length from 70 to 500 feet or more; the veins average in thickness

from 2 feet to 8 feet, and the walls are hard and firm. A large amount of ore has been taken from them near the surface and worked, and we are now preparing to open and work them at a depth.

We are running two mills-a stamp mill and a concentrating mill. The stamp mill is an ordinary mill of that sort. It contains 15 stamps, in 3 batteries of 5 each, with self-feeders, ore bins, and plates. We work all the fine part of the quartz here, so no rock breaker is required; and as the fine quartz carries little or no mineral, we have no concentrators here.

The stamps weigh 750 pounds each, work under a 6-inch to 8-inch drop, and drop 96 times a minute. We crush through a No. 5 slot screen, and crush 26 tons to the stamp in 24 hours.

We amalgamate entirely outside. For this purpose we have silverplated aprons below the mortars, each apron being 4 feet 4 inches wide and 12 feet 6 inches long, with a grade of 18 inches to the foot. Below the aprons we have 12 feet of spout plates to each apron, 18 inches wide by 12 feet long, grade of an inch to the foot. The free gold in our rock, especially in the finer rock, is very fine flour gold. It is worth $18 50 an ounce, yet an ounce of dry, hard amalgam will only retort about one fifth gold. We have experimented with crushing through every size screen from No. 9 down to No. 4, and we find that although our gold is so very fine, yet we save the most per ton in crushing coarse through a No. 5 screen, and at the same time have a largely increased capacity over a fine screen.

The coarse rock and all the sulphur-bearing rock goes to the concentrating mill. This mill is constructed on a different principle from most mills of the sort, as we use Tustin pulverizers instead of stamps for crushing the quartz. The ore first goes through a 12-inch Blake rock breaker and then drops into the ore bin, from which it is fed to the Tustin pulverizers. These pulverizers are provided with automatic self-feeders, the same as we use in the stamp mill, and they feed the same way. We crush wet and amalgamate on aprons, after which the pulp is concentrated on Frue

vanners.

We run four pulverizers. These run at 20 revolutions a minute, requiring 4-horse power each. We crush through a 20-mesh steel wire screen, the capacity of each machine being from 10 to 11 tons a day on the kind of rock that comes to it. The aprons are silvered plates, 4 feet wide by 10 feet long; grade, 1 inches to the foot. We use 8 Frue vanners, 2 to each pulverizer. Our coarse rock carries a very small per cent of sulphurets, fromto of 1 per cent. The sulphurets, however, are very high grade, some being worth, when pure, upwards of $5,000 a ton. We concentrate our rock up to from 82 to 88 per cent of the assay value, according to the kind and grade of the rock.

A comparison of the two methods of crushing shows a marked difference in results. In crushing through the battery a large amount of slimes are produced. With the pulverizer a very small quantity of slimes is made. As a consequence, with our ore, where the rock is very hard, the gold exceedingly fine, and the sulphurets soft and brittle, we find that on the same ore we amalgamate a much greater percentage of the fine gold after the pulverizers than after the stamps; and when we come to concentrate, we can save only 18 to 20 per cent of the assay value of the ore after stamps, and 85 per cent after the pulverizers. On the same ore and with same screen our pulverizer is about the equivalent of 6 to 8 stamps, according to the character of the ore.

Our sulphurets we work ourselves, by roasting and chlorination. Our roasting works consist of two "Willard" furnaces, with all necessary appurtenances. These furnaces are of a ton capacity each to the charge, and

we can roast, if necessary, from 6 to 8 tons a day. The chlorination works are of equal capacity, consisting of 11 pairs of leaching and settling tanks, with generators, etc. We roast the sulphurets, granulate them, and run them in a car to the chlorination works. After which, they are treated in the usual manner, and the gold leached and precipitated.

We run entirely by water power. We use 130 inches in the mine. In the stamp mill we use, for power and amalgamating, 80 inches, under 140foot head. In the concentrating mill we use, for power, amalgamating, and concentrating, 100 inches, under 160-foot head.

The cost of mining is about 50 cents per ton of quartz, delivered at mill. The average cost of milling in the two mills is about 60 cents a ton.

We employ 12 men altogether about the mine, including men in the open cut at the chamber and dump-box, and car men. In the mills we employ 7 men, and at the chlorination works 2 men, making a total of 21 men, on an average.

We have done no development work the past year, but are now putting up compressor, etc., for power drills, and propose soon to open up various veins at a depth.

The county is bounded on the north by Placer; on the east by Alpine County and the State of Nevada; on the south by Amador and Alpine Counties; and on the west by Placer and Sacramento. Geologically it differs but little from Amador, Calaveras, Tuolumne, and Mariposa Counties. The belts of limestone and granite and volcanic flows, form about the same prominent features within its boundaries as they do in the counties to the south through which passes the great auriferous lode. The county is celebrated for having sent forth to the world the first authentication of gold having been found in the State. Latterly renewed activity has been displayed in developing the mineral resources of the county, consequently many rich finds have been recorded.

SPRINGFIELD MINE.

This mine, formerly known as the Church Union, is the representative mine of the county; is situated at an altitude of 1,200 feet above sea level. The dimension of the claim is 4,500 feet on the lode; course of the vein is north and south; the dip about 80° to the east, and the average width about 3 feet. On the property is a 15-stamp water-power mill, using 110 inches of water, under a pressure of 450 feet, every 24 hours. Each stamp weighs 600 pounds, falls 9 inches, at the rate of 90 times per minute, and crushes 13 tons of ore per diem. The ore, free milling, containing about one per cent of sulphurets, is worked after the usual method of amalgamation in batteries and collection on outside plates. The sulphurets, after collection on Frue vanners, are worked by the chlorination process at the company's works, at a cost of $10 per ton.

This mine, formerly known as the Sam. Sims, in Coloma Mining District, is noted as the first place in which the mineral roscoelite was found, and is worked solely as a pocket mine. A shaft has been sunk on an incline of 45° to connect with a tunnel 300 feet long. The claim is 1,500 feet long by 600 feet wide, and carries a five-foot vein; the hanging-wall is syenite, and the foot-wall is slate. The method of reduction and recovery is in the hand mortar and an arastra run by horse-power. The property was located in 1868, and from that date to the present time there have been several successive owners, all of whom have retired well recompensed.

FRESNO COUNTY.

ABBEY MINE.

This mine, owned by G. W. Grayson & Co., is situated in Fine Gold Mining District, in a formation of granite, at an altitude of 1,700 feet above the sea. The vein is about two feet in width; has an east and west course, and dips 22° to the north. The mine is worked through a shaft, which, on the incline, is 1,500 feet-reaching a perpendicular depth in the mine of 300 feet. The formation of the hanging-wall is granite, and of the footwall, syenite. The developments are three tunnels 200, 300, and 400 feet, respectively; a shaft 500 feet in depth, from which tunnels are run from the various levels on the vein, the longer of which is 300 feet easterly and 125 feet westerly on the vein.