The mill and hoisting works were old and entirely worn out. There were two quartz mills, one of 36 and one of 24 stamps. The stamps weighed only 500 pounds, dropping 75 times per minute. The mortars were old fashioned. The concentrators were concave buddles and sluice boxes. The 60 stamps did not have the crushing capacity of a modern 40-stamp mill. Furthermore, although there are no records relating to the subject, the character of work done in saving gold must have been very poor.

No steam is required for power either for mill or hoisting works. The Mokelumne Hill and Campo Seco Water Company's ditch passes above the mine, giving 300 feet head at the hoisting works delivered through a pipe 100 feet long. To pump and hoist from the 1,500 level, and run 60 stamps, required 180 miner's inches. The cost is about 16 cents per 24

hour inch.

Regarding the water in the mine, no difficulty was ever experienced in keeping it under control till the 1,400 was reached, with a 5-inch pump 30inch stroke, running 8 strokes per minute. At the 1,500 a slightly increased amount was met with which the same pump could have controlled were it possible to increase the speed; this, however, could not be done, owing to the crooked condition of the shaft.

FINE GOLD MINE.

The mine is situated at an altitude of 3,000 feet above the level of the sea, in Railroad Flat Mining District, and is 1,500 feet in length by 600 feet wide. The course of the vein is north and south, dipping 70 degrees westerly, and averages 5 feet in width. The hanging and foot walls are slate, and the quartz is free milling, containing about 2 per cent of sulphurets, but not of sufficient value to pay for collecting and working. Developments on the property, beside the shaft 250 feet in depth, are three levels running north and south on the vein, from 400 feet to 600 feet in length, all of which were made during the year 1886. The machinery consists of water power, 10-stamp mill, hoisting works, and air compressor. The stamps weigh 750 pounds, drop 7 inches 100 times per minute, and crush 21 tons of ore per day. The apron plates are 4 by 44 feet, and the sluice plates are 16 inches wide by a length of 100 feet to each battery. The saving of the yield is about equally divided between the batteries and plates.

Size of screens, mesh

Miner's inches of water used in 24 hours in mill.

Miner's inches of water used in 24 hours in hoisting works.

Miner's inches of water used in 24 hours in compressor

(Contributed by F. B. MORSE, E.M.)

The property belonging to the Willard Mining Company is situated in Calaveras County.

Murphys Mining District.-The altitude is about 2,200 feet above sea level. The formation is limestone and slate. The accompanying sketch marked Fig. 1 is a diagram of the formation; the line marked cc'ce being the line of contact. The apparent stratifications of the slate and limestone are conformable and run nearly east and west, the line of the contact cutting the formation. The positions of the different veins are also shown in this diagram. They consist apparently of a main opening, marked AA, and small side veins, marked BB, DD, etc., running into the main -opening on either side.

The main vein, AA, is called the "Red Wing" vein. The dip of this vein, as far as known, is nearly vertical; course about 15° north of west and south of east. The dip of the side veins is about 78° to the south; course nearly east and west. We have six locations covering the different veins, five being 600 by 1,500 feet, and one being 300 by 1,500 feet.

We have opened two shoots or bodies of ore on the main opening, one marked MM and the other NN. The length of either is not fully known, but in each case is probably about 1,000 feet. The width between walls varies up to 300 feet, with a maximum width of the ore bodies of 200 feet. The ore body MM is opened by a tunnel, marked TT, 800 feet into the hill. This tunnel crosscuts the vein. The crosscut shows both walls, at this point, to be limestone. The opening between lime walls is 300 feet. In this opening is 200 feet of vein matter, with 50 feet of birdseye porphyry on either side of the vein between it and the lime walls.

From the point marked c', the vein, going westerly, follows the contact between the lime and the slate, the north wall being lime and the south wall slate, the contact and the vein cutting the formation at an angle of about 15°.

From the point marked c'-going easterly-the contact makes a bend towards the south. The vein, however, does not follow the contact, but continues its course, cutting across the limestone, both walls now being lime. The main vein here still cuts the formation at an angle of 15°, the side veins running into it being conformable with the apparent stratification.

The ore in all the veins is an exceedingly hard quartz, carrying gold, silver, and what is nominally gray copper, galena, and zinc blende. This ore has several interesting peculiarities. In the first place, it carries absolutely no iron pyrites-which are found in considerable quantities in every other gold-bearing vein in our section, outside of this particular belt of veins. Again, the gray copper-or what is nominally such-is shown by analysis to contain very little sulphur-which is largely, and, in some cases, almost entirely replaced by selenium. And besides copper, the mineral carries gold, silver, lead, zinc, bismuth, antimony, iron, and manganese.

Another peculiar feature of the main vein is this: In cross-cutting the vein in the tunnel TTT, the quartz for the first 150 feet carried free gold, and the sulphurets were nomihally pure gray copper, no galena or zinc blende being found. The ore assayed ounce for ounce in silver and gold; and the loose gold in the clay seams was worth about $19 an ounce. For the last 50 feet the quartz carried little or no free gold. The sulphurets were galena and zinc blende, and the loose gold was very silvery-being worth only $14 an ounce. The sulphurets here assay from 6 to 8 ounces in silver to 1 of gold.

The same peculiarity is noticed in all the side veins; those on the south side of the main opening carrying free gold and gray copper, with no galena or zinc blende; while those on the north side carry little, and in some cases, no free gold, and no gray copper, but carry galena and zinc blende assaying high in silver.

In the main opening AA the vein-matter between the porphyry walls consists of strata of quartz and porphyry. For a depth of 300 feet, in some cases, from the surface, the vein is decomposed and disintegrated, so that it bears some resemblance to a gravel-bank, though the quartz is all sharp. This decomposition has broken up the quartz into pieces from many tons weight down to fine sand, and the porphyry in many places has been changed to clay.

Our method of working this vein is by an open cut from the surface, making a funnel-shaped hole, connected by a shoot with a tunnel below, through which all the material mined is run out. The sketch marked Fig. 2 shows the present appearance of the pit and of the arrangement of the tunnel.

The tunnel is run in from the surface, so as to partly cross-cut the formation. The grade of the tunnel is about 5 inches in 12 feet, and it is wide enough to allow a track, flume, water pipe, and air pipe to run all the way in. At the end of the tunnel, and under the pit, is a chamber 9 feet by 25, and 20 feet high in the clear. This chamber is connected with the workings above, by what is now a short shoot. At the bottom of this shoot is a large gate; below the gate is a grizzly and a platform and a small bin, for loading into a car. The flume which runs through the tunnel comes in under the grizzly, and the water pipe connects with a small tank at the head of the flume.

Our method of working, in detail, is as follows: In the open cut we run powder drifts, with TT, as in bank blasting. We run the drifts in about 15 feet from the face of the bank, and the TT from 15 to 20 feet on either side, usually taking a 15-foot face to the bank, on a stope up from the bottom. We load from 150 to 300 pounds of powder (low-grade powder) in each T, and fire by battery. One such shot will dislodge from 3,000 to 4,000 tons of material, which is thrown down to the bottom of the pit and into the shoot. It is then drawn from the shoot as fast as wanted, by means of the gate. As it comes through, it passes on to a grizzly, the