and the working vein has an average width of 15 feet of talcose slate mixed with quartz. The quartz-lode is 150 feet west at the surface, and it is supposed that the two will meet about 300 feet from the surface. There is a good gouge on both sides and clay slate walls to the vein. The mine has been worked for 10 years, and is now yielding $8 per ton, though assays show that the rock contains from $15 to $20. The gold is very fine. The mine has a 30-stamp steam mill, with a Blake crusher to prepare the rock for the stamps, two Wheeler pans for grinding, a Belden settler, and lately an experiment has been tried with one of Hesse's pans. The pulp is discharged from the mortar through a slot screen, the orifices being as wide as those in a No. 40 wire screen. The advantage of the slot screen is that it discharges more freely, as the holes are not plugged up by the sulphurets. The deepest workings are 186 feet deep, and the drifts extend along the vein 350 feet, in pay all the way. Most of the early workings were in open cut, and the rock was richer at the surface than in the lower levels. HILL.-Dr. Hill's mine, 412 feet long, is also working on the talcose slate vein, which averages 15 feet wide, and contains much silicate of lime, besides quartz, the slate occupying a very subordinate portion here. The proprieter of the mine says that most of the gold is found in threads of sulphate of barytes, and in bunches of silicate of lime. Work was commenced on the mine in 1857 with arrastras, and has been continued since with the exception of three years. The total production is estimated at $250,000, and the amount spent in the mine, $300,000. There is now a 12-stamp mill at work on it. The depth from the dies in the mortar to the discharge is 14 inches, and the stamps when raised to their highest point are two inches deep in the water. For a time no screen was used, but the result of the experiment was not satisfactory. The present screen is of No. 60 wire. Hunter's amalgamator and Hill's pan are used. The latter, named after its inventor, the owner of this mine, is a circular copper dish six feet in diameter, six inches deep. A section through the centre represents a segment of an oval. This bowl revolves horizontally on a central axis, and in the centre is a cup to hold quicksilver. The pan makes 18 revolutions per minute. The whole surface of the pan is covered with amalgam. One of these pans at the mill of the Angels Quartz Mining Company saves $200 per month, it is said. In Hill's mine there are numerous horses of barren slate, and in one place a trachytic dike 15 feet thick crosses the lode running westnorthwest and east-southeast. About five per cent. of the pay rock consists of sulphurets. The silicate of lime gives a milky look to the pulp as it comes from the mortar.

STICKLES.-The Stickles mine, 400 feet long, near the town of Angels, on the mother lode, which is there 20 feet thick, is quartz and pay all the way through, with numerous seams of slate. The deepest workings are 80 feet below the surface, and drifts have been run 120 feet on the vein, in pay rock all the way. There is a 10-stamp mill in operation on the mine.. UTICA.-The Utica, 600 feet long, is owned in San Francisco. nine-stamp mill which did not pay, and has been moved away. The deepest workings are 60 feet from the surface.

There was a

LIGHTNER. The Lightner mine, 400 feet long, owned in San Francisco, was worked in open cut for three or four years to a depth of 70 feet with a 10-stamp mill, but the expenses were a trifle more than the receipts, and so the mill was moved away and the mine left idle. If wages were a little lower this mine would pay, for, according to the general opinion in the neighborhood, there is a large body of rock that will yield at least $4 or $5 per ton, and probably $6 or $8. ELLA. The Ella mine (known also by the names of the Calaveras, the Terrific, and the Demorest) is seven miles northwest of Angels, on a vein which is eight feet wide and crops out along the surface for 800 or 1,000 feet. The vein-stone is a hard ribbon rock, rich in sulphurets, with a seam of barren "bastard quartz" in the middle. The ribbon rock yields $8 per ton. The foot

wall is black slate and the hanging wall green-stone. A shaft has been sunk 110 feet, and drifts have been run 35 feet on the vein. The mine is in a deep ravine at the foot of Bear mountain, with steep hills on both sides. There is a 10-stamp mill, but both mine and mill are now standing idle.

At this mine an experiment was tried of roasting the rock with superheated steam. A furnace was built 20 feet high and 16 feet in diameter externally, with an ore chamber seven feet wide at the bottom, nine feet at the top, and 16 feet high. The fire boxes were on the sides of the ore chamber near the bottom, and over the grating ran a steam pipe full of orifices, through which steam could escape. The rock as it came from the mine was thrown into this furnace, and was roasted from 40 to 70 hours at a red heat with a steady discharge of superheated steam from the pipes. The heat was reduced by shutting off the steam, or increased by letting on more. The expense of roasting in this method was $2 per ton, the price of wood-the only fuel used-being $3 50 per cord. The sulphurets were completely desulphurized by this method, and the battery crushed twice as much in a day as of the run rock. The gold in the roasted orc amalgamated readily, but the quicksilver was lost. The experiment cost $25,000, and was regarded as a failure.

WEST POINT.-West Point is a quartz mining town between the middle and the north fork of the Mokelumne river, eastward from Mokelumne Hill, from which it is 12 miles distant in a direct line, and 16 miles by the road. Its elevation is about 2,800 feet above the sea. The bed rock is granite, and the limestone belt lies three miles to the west. Quartz mining is conducted here on a peculiar system. The lodes are narrow and rich in sulphurets, and their wealth is confined chiefly to pockets. Mining and milling are separate occupations. One set of men get quartz, and another set own mills and do customwork. The "pockety" character of the veins renders mining, with the majority, a very irregular, if not a very uncertain business; and there is not one vein in ten, even among those which have yielded large sums, that will furnish steady employment to a mill. The custom among the "pocket" miners is to hunt for pockets near the surface, and when they have found one they clean it out carefully, going down seldom more than 50 feet; and having pounded out the coarsest gold in a hand mortar, and sent the quartz containing the finer particles to a custom mill, they leave that spot and hunt for another pocket near the surface. The experience of those who have gone down in search of other pockets has not been encourging. The prospecter lays bare as much of the surface of the vein as he can, and goes picking along in search of a visible speck of gold, and having found that, he makes a careful search for a pocket in the neighborhood. When these pocket miners are successful they get a good lot of money at once, and many of them live high till it is gone, and then they may have very plain meals for three, six, or nine months, before they come on another treasure. It is said, however, that they have more money to spend than any other class of miners in Calaveras county. There are some mines here which give regular employment to mills owned by the same proprietors, but pocket mining and custom milling are followed more extensive here relatively than in any other part of the State. There are about 100 men who make pocket mining their only business. If the quartz does not yield $15 per ton it will not pay them; and they can tell by a brief examination within a dollar or two of the yield per ton. When they have found something worthy of examination, they pound up a fair sample in a hand mortar and boil it in nitric acid, as a rude mode of assay.

In the neighborhood of West Point there are several hundred veins that have had rich pockets, and one hill 400 feet across has three dozen such veins. In many of them the gold is so fine that none of it can be obtained in a hand mortar. The mining laws of West Point give 200 feet on a vein to a claim, and require one day's work every month to hold a claim.

F

FISHER'S MILL.-Fisher's custom mill, one mile southeast from West Point, has been running 11 years. It is driven by water-power, has two stamps and two arrastras, charges $7 per ton for working rock, and works two tons per day, with the services of one man. The whole establishment cost about $2,000. HARRIS'S MILL.-Harris's custom mill, on Sandy gulch, a mile and a quarter west of West Point, has five stamps, four Brevoort pans, and three patent concentrators, and charges $5 per ton for working rock. This mill was built four or five years ago, and has been running almost constantly.

BELCHER'S MILL.-The Belcher custom mill, a mile and three-quarters southeast of West Point, has eight stamps, but does not run regularly because of the difficulty of getting a steady supply of water.

LACEY'S MILL.-Lacey's mill has five stamps, and does custom work only. SKULL FLAT MILL.-The Skull Flat mill is two miles east of West Point, has ten stamps, goes by water, amalgamates in the mortar and in copper-plates, and uses two Hungerford's concentrators, but does nothing as yet with the concentrated tailings. The Skull Flat Company owns claims on six or seven veins, the widest not over two feet, and a depth of 100 feet has been reached in several of them. The veins run north and south, and the rock pays $30 or $35.

CARLETON.-The Carleton mine, a mile and a half northwest of West Point, is on a vein a foot wide. There are two arrastras which were built in 1866, and crush and amalgamate each a ton per day.

VANCE AND MINA RICA.-Vance's mill, five miles west of West Point, has eight stamps, and is standing idle. The Mina Rica has two veins two feet thick, with very hard quartz, and much water in the lower levels. The mill has 10 stamps and 10 Baux's pans. The power is steam. Both mine and mill are standing idle.

MORRIS'S MILL.-Morris's mill, near West Point, has two arrastras and a roasting furnace. All the ore is roasted, and according to report the yield is $50 per ton, whereas without roasting it yields only $3.

MOSQUITO.-The Mosquito mine, 1,500 feet long, is five miles west of West Point, on a vein five feet wide in slate. A large quantity of rock, yielding $7 per ton, was obtained near the surface; and now a tunnel is being cut to open the mine to a considerable depth. The mill was built in 1857, and was rebuilt in 1863. It has 15 stamps, and is standing idle.

RAILROAD FLAT MILL.-The Railroad Flat custom mill, 13 miles east of Mokelumne Hill, has 10 stamps, was built in 1866, and does not get enough business to keep it running constantly. The veins in the vicinity have not been well opened.

WOODHOUSE.-The Woodhouse mine, 5,000 feet long, is between the forks of the Mokelumne river, 14 miles by the road, eastward from Mokelumne Hill. The vein is four feet wide, runs north and south, and dips to the west at an angle of 45°. The walls on both sides are granite, and there is a white clay gouge, which is generally found on the foot wall. The croppings of the vein show for two or three miles. The pay quartz is white near the surface, and at greater depth is bluish and rich in sulphurets. The barren quartz is white, glassy, and coarsegrained. The first pay chimney is found 1,800 feet from the south fork of the Mokelumne river, (which is the boundary of the claim,) and 900 feet above its level on the mountain side. This chimney is 150 feet long horizontally. After an interval of 600 feet another chimney is found, and this one is 400 feet long, beyond which the lode is barren for 200 feet, and then it splits up for 1,000 feet into small branches less than a foot wide. These contain good pay, and one shaft has been sunk 100 feet to work them. Beyond this place the vein has not been prospected. The rock from the different chimneys can be distinguished by persons familiar with the mine. All the rock in the pay chimneys is worked. The vein is crossed by several trap dikes which are nearly vertical, dipping slightly to the south. They appear to bear no relation to the position of the pay

chimneys; that is, the appearance of a dike is not considered an indication of the proximity of a chimney. Most of the work has been done through cross-tunnels which strike the vein 200 or 300 feet from the surface. The mine has a 15stamp mill, which has crushed 14,000 tons of rock and taken out $140,000. After the pulp has been amalgamated in the mortar and on copper-plates, it is concentrated on blankets, and the blanket washings are ground and amalgamated in five Brevoort pans. The mill is driven by two 30-foot overshot water wheels. There is a considerable quantity of loose or "float" rock along the surface of the vein, and 3,000 feet of 11-inch iron pipe are to be obtained for the purpose of washing this float rock by hydraulic process. Much of the gold in the rock from the lower levels is lost in the sulphurets, and an agreement has been made for the erection of a revolving furnace to roast 15 tons in 24 hours, at a cost of $3 per ton.

HOLMES.-The Holmes mine, 1,600 feet long, south of the Woodhouse and adjoining it, was opened in 1866. The vein is eight feet wide, and has been opened by tunnel along a length of 500 feet. The mine has a 10-stamp mill. The sulphurets contain from $300 to $1,300 per ton.

BOSTON.-The Boston mine adjoins the Woodhouse on the north, and was worked by an eight-stamp mill in 1853, but did not pay. The mill was washed away afterwards. Some Mexicans are now at work on the mine, with two arrastras driven by water. They obtain their rock from small rich chimneys. QUAIL HILL.-Quail Hill, near the western line of the county, has a large deposit of auriferous talcose slate, containing seams of quartz and copper ore. It is not a well-defined vein, but the general course appears to be northwest and southeast, and the dip 60° to the northeast. The width is about 60 feet. Much

of the surface has been washed in sluices, which paid at times very well. The total yield in sluices was not less than $25,000, and besides the gold 150 tons of good copper ore were obtained. This mine is the property of a San Francisco company, which is now building a 20-stamp mill and constructing a ditch 11 miles long from Salt Spring reservoir.*

* Professor Silliman, in a paper read before the California Academy of Natural Sciences, said:

In the search for ores of copper which occurred in California in what is now known as the copper belt of the Lower Sierras, deposits of iron rust, as they were called by the miners, were observed at numerous points far below the range of the main gold belt of the Sierras. Several of these ochraceous deposits had been previously located by prospecting miners for gold before there was any knowledge or suspicion even of the existence of ores of copper in connection with them. It was a matter of common observation that certain gulches or watercourses in the neighborhood of these rusty deposits were rich in placer gold, having been worked for gold from an early date. The search for copper in this kind of deposit was not commercially successful, although there were shipments of green and blue carbonates of copper, red oxyd, and metallic copper, to a limited extent from both the localities here referred to, (the Harpending mine in Placer county, and the Quail Hill in Calaveras,) the metal from which was known to contain a notable value of gold and silver, stated to be about $50 to the ton of ore. This search for copper has however opened up these deposits so as to display their character in a conspicuous manner.

The rocks appear to have been originally talcose and chloritic schists, sometimes micaceous, enclosing masses of argillite, and of quartz, which appears to have been massive enough at certain points to assume the character of a vein, and parallel to the stratification, which has the usual northwestern strike and easterly dip of the region, All this mass of material, which at Quail Hill is certainly 300 feet wide, and possibly twice that, and with a linear extent exceeding 1,000 feet, appears to have been very highly impregnated or mineralized by sulphurets, chiefly of iron, with a portion of copper, zinc, and lead. The sulphurets have undergone almost total decomposition throughout the entire mass, leaving soft ochraceous deposits of a rusty red and yellow color, and staining the rocks with brilliant color, a peculiarity which the miners have characterized by the name of "calico rocks." This decomposition or oxydation of the sulphurets has extended to a point as low as atmospheric influences extend, or probably to a point where water, is permanently found, which at Quail Hill is assumed to be about 170 feet below the outcrop of the mass. Dikes of porphyry and of other rocks commonly called intrusive are seen dividing these great ore channels in a direction conformable to the line of strike. But the decomposition which has

t

COLLIER.-The Collier claim, one mile southeast of Quail Hill, is similar in character to the preceding mine, and has been worked in the same manner. The total yield is estimated at $10,000. It is said that if the mill at Quail Hill succeeds one will be built here.

affected other portions of the ore channel appears also to have changed them, for they are found to be reduced completely to the condition of kaolin and lithromarge, or kindred alterations of feldspathic rocks. The outlines of the feldspar crystals are still easily distinguished, although the mass of the dikes is completely friable.

In another paper on the mine Professor Silliman says the explorations made for copper have laid open the deposit sufficiently to disclose clearly its true nature, extent, and almost incalculable value in gold and silver. It is an ore channel, conformable like all the copper mines of the region to the line of strike of the rocks, not less, probably, than 300 feet in width, and perhaps more than twice that width. Its eastern wall is distinctly seen in the open cut, as shown in the section, dipping easterly about 70°. The western wall has never been seen, but is certainly pretty far down the slope, on the western side. The contents of this enormous channel of ore-bearing ground, so far as exposed, are entirely decomposed by chemical agency, so that they offer to the miner and geologist one of the most remarkable cases known of the total destruction of metallic sulphurets which plainly once filled the whole chasm, now converted into gossans or oxides of iron of various colors, and carbonates of copper, mingled with masses of spongy and white quartz, of talcose and chloritic rocks, rotten porphyry, heavy spar, &c., &c., all so completely changed and decayed by the causes alluded to that the entire mass yields to the pick and shovel in any direction. This extreme decay of the original contents renders the study of the mass at first a little difficult; no sulphurets of any kind remain visible to guide the eye, but in their place everywhere the results of their decomposition.

The mass is evidently a gigantic vein, the main constituent of which was a highly sulphuretted quartz, holding originally iron and copper pyrites throughout its entire mass; these sulphurets, and the quartz itself, being very uniformly impregnated at all parts with gold and silver. Examined by the battea, the pan, or the horn spoon, no part of the contents of this great ore channel fails to give abundant "prospects" of gold. Even the dry cherty croppings broken from all parts of the hill, without selection, gave an ample show of gold. The gulch at the base of the hill has always yielded good washings, and does so still, the source of which is from the ores of Quail Hill. I found the gold in nearly all the varieties of mineral contents contained in the hill, showing that any attempt at selection would be useless, and that the whole of the mass must be worked as it runs, except certain layers of soft white rock, resembling kaolin, which are probably too poor in gold to pay for working. EXTENT OF EXPLORATIONS.-This mass has been opened by a cut driven 82 feet into it, beyond the line of the east wall, by an incline 57 feet long, at an angle of 38°, and by a shaft 42 feet below the cut, sunk in pursuit of copper ore. The shaft in the open cut explores the mass over 80 feet below the walls of the cut and nearly 150 feet below the crown of the hill. Another shaft, sunk 100 feet south of the open cut, opens the deposit to a total depth of 90 feet under the crown of the hill. Near Gopher Gulch is another shaft 62 feet deep, which passes into the unchanged sulphurets 25 feet, it is said, from its mouth, (this shaft has water in it now,) or about 170 feet under the hill.

The position of all these openings is seen on the map; but there is a tunnel, not shown on the map, run some 70 feet into the hill, on the west side, and several hundred feet (about 850 feet) beyond the western limits of the location, in which the entire mass of the hill is still seen to be completely decomposed at that part also, the tunnel having been run by the pick alone. From this tunnel I obtained spongy quartz, which prospected well for gold; but this point is very far west of the supposed productive limits of the deposit. Numerous surface-pits have also been sunk over the hill in various places for the purpose of obtaining averages, from all of which gold prospects may be obtained in the pan.

VALUE OF THE ORES.-I collected for assay and practical workings careful samples

from

I give here only the general results and averages, viz:

(1.) The average from the three places named above was by working tests: