Experienced quartz miners, familiar with the estate, are almost unanimous in the opinion that the Princeton, the Pine Tree, and the Josephine mines are far from exhausted, but, on the contrary, that they are all very valuable, and ought to be made to pay well, and that the failures of the last four years are to be ascribed mainly to bad management. It is true that when the Mariposa company took possession the mines were not opened in advance as they should have been; but they were opened, the position of the pay chimneys was determined, the hoisting works and pumps and mills were in working order, with capacity to crush and amalgamate 150 tons of rock per day; there were experienced miners present, familiar with the character of each vein; there was a railroad for transporting the rock of two of the principal mines to the mill; and there were improvements that were indispensable, and that could not have been placed there for less than a quarter of a million dollars. The property, however, was not managed properly, and the result was a failure, which is the more remarkable because it followed immediately upon the heels of the most brilliant

success.

PRINCETON.-The Princeton mine has been one of the most productive in California, and has been noted for both the abundance and the richness of its quartz. For a time it yielded $90,000 per month from milling rock, and this is more than any other mine of the State ever did.

The mine is situated about half way between the Mariposa and the Pine Tree mines, and is on a hill easily accessible. The course of the vein is northwest and southeast; the dip, 55° northeast; the thickness varies from a few inches to 10 feet. The vein has been opened to a depth of 560 feet on an incline, and 200 feet below the surface; drifts have been run 1,200 feet along the vein, and at the deepest workings the drifts extend 500 feet. The richest rock was found within 100 feet of the surface, where the pay was $70 per ton from milling well, besides large numbers of specimens, of which it is said that not less than $100,000 in value were stolen by the miners. Below this rich mass of rock the quartz gradually became poorer, and there were spots which did not pay for working; but it is said that there is still an abundant supply of good milling rock in sight.

Professor W. P. Blake made a report on the mine in November, 1861, and said:

The vein is composed of white friable quartz, and is divided into parallel layers or plates by thin slatey films, which are generally charged with fine-grained pyrites and free gold. The body of the quartz bears white vein pyrites crystallized and spread in irregular patches and a small portion of galena, together with free gold in irregular ragged masses, in plates and scales, and sometimes crystals. The gold appears to be most abundant in the neighborhood of the galena, and is found not only with the iron pyrites striking its sheets through its substance, but entirely isolated from it and enveloped in the pure white quartz. Some of the specimens preserved are exceedingly rich and beautiful, and just before my examination of the vein some superb crystallizations had been broken out. These crystals are bunches of octahedrons, with perfectly flat and highly polished faces from one-eighth to three-sixteenths of an inch across, and are attached to masses of white quartz.

openings by enlarging the working facilities, to 4,000 tons per day. The cost of mining and reducing the ore will be less than $10 per ton, and may yield an average of $40 per ton. The old mills have produced upwards of $3,500,000. Under an intelligent system of working they ought to have yielded over $10,000,000.

The amount of profits from the estate can only be estimated in proportion to the number of mills provided for the reduction of the ores. The reader may draw his own conclusions from the facts and figures herewith presented.

It will be remembered that the representations heretofore made by the undersigned were based on the low estimate of a sure gross average yield of $20 per ton, by the new reducing machinery. The present working shows that such estimates may no longer be regarded as theoretical, as the actual results fully illustrate. Theywill be amply confirmed by the future of this great property.

Professor Blake made a second report on this mine in December, 1864, and said:

It is evident on a careful examination of the surface that there is a want of conformity in direction between the vein and the slates. The slates on the west side are curved towards the vein in the form of a bow, the ends of the curve appearing to abut against the vein at both ends, the vein forming in its line of outcrop, with respect to the slates, the chord of an arc. There is also a want of conformity in direction between this body of curved slates on the west side of the vein and those on the east side of it, showing with most distinctness at the north end, near the mouth of the upper drift. On the east side the trend of the slates is seen to vary at different places from north 45° west to north 95 west. They are nearly east and west at the north end of the vein. * * * There is also a want of conformity between the body of curved slates on the west side of the vein and the slates still further to the west, as if the curved body of slate had been broken from some other place and forced into its present position. The line of contact is not very distinct, but just in the position we would expect to find it we see a quartz vein which seems to mark the place. It is approximately parallel with the Princeton vein, and is also gold-bearing.

This want of conformity in the direction of the slates on the opposite sides of the vein and with the course of the vein itself, and the fact that the ends of the layers of slate abut against the vein, or in other words, that the vein does not coincide with the plane of the bedding or stratification of the slates, justifies the conclusion that it is a fissure vein rather than a bedded mass, as has heretofore been generally supposed. It evidently occupies the line of break between the two distinct bodies of slate.

The mineralogical character of the slates on the opposite sides of the vein is also different. The slates on the west side are much more sandy than those on the east, which are argillaceous and in very thin layers of uniform composition, presenting the well-known appearance and character of roofing slates. There are several layers in the series on the west side which might be called sandstones rather than slates. There are also in connection with these sandy bars of a hard argillaceous rock, with an obscure slaty structure which resists weathering more than the surrounding portions and stands out in well-defined outcrops. These two bars of rock are each from six to eighteen inches in thickness, and are about 170 feet apart.

It is a curious fact that the gold-bearing part of the vein appears to have a certain relation to these peculiar argillaceous rocks or strata, for it does not extend beyond the line of contact of these strata with the plane of the vein. So also in the northern extension of the Princeton vein, half a mile to the northwest, at the Green Gulch mine, where the vein was productive, the same peculiar rock is found in connection with the vein on the west side.

In 1862

Near the mill the vein splits and the two branches run off southeastward nearly parallel with one another. At a distance of a mile they are about 300 yards apart. These branches have not been well explored or prospected, so not much is known of their character. On the main vein there are seven shafts and a great number of workings of different classes, such as might be expected of a mine that has yielded $4,000,000 and sustained a considerable town. From January, 1859, till June, 1860, Steptoe and Ridgway had charge of the mine, and extracted 2,000 tons, which averaged $18 per ton. From June 1, 1860, till November of the same year, under the management of Park, 23,916 tons of quartz were crushed, yielding $527,633, an average of $22 25 per ton. and 1863 the production was 121,000 tons of quartz and $2,000,000 of bullion, averaging $16 50. In 1864 the yield of bullion was $243,707. In 1863, when the mill was working rock which yielded $53, the tailings, according to assay, contained $13 56 per ton. The pay was distributed rather in an irregular mass than in a chimney; but Professor Blake expressed the opinion in his report of 1864 that there was a chimney, and that its dip was 18° to the horizon. The Princeton mill has 24 stamps, and is the smallest on the Mariposa estate, at least of those owned, erected, and worked by the Mariposa company. The capacity of the mine far exceeds that of the mills, and while the former was in a productive condition much of the ore was sent to other mills. The gold in the quartz is coarse and is easily caught in the battery, or at least most of it; but the assays of the tailings show that great quantities of it were lost. The heap of tailings at the mill is immense, and it will no doubt be worked over at some day with a profit, if not all blown away. The sand being fine many pounds of it are carried off every hour when the wind blows in summer. The

mill was driven by steam. The stamps weigh 550 pounds and made 70 drops per minute. Both mine and mill are now idle.

THE PINE TREE.-The Pine Tree mine, contiguous to the Josephine, and thirteen miles from the town of Mariposa, is considered to be on the main mother lode, which runs northwest and southeast, dips to the northeast, and is here in places 40 feet thick. The ore is extracted through tunnels and carried down to the mills on a railroad. The workings are 500 feet deep and 1,000 feet long in the vein. There are seven pay chimneys, which vary in length, horizontally, from 40 to 200 feet. The rock in each chimney has a peculiar color or appearance, so that persons familiar with the mine could tell at a glance from which a piece of quartz came. The coarsest gold was found in the narrowest chimney. In three years previous to May, 1863, the Pine Tree and Josephine mines produced 45,000 tons of ore and $350,000 in bullion, an average of $7 77 per ton. In 1860 these mines produced 12,154 tons and $113,530, or $9 34 per ton; in 1861, 21,576 tons and $173,810, or $8 05 per ton; in 1862, when the dam was carried away by the flood, nothing; and in 1863, previous to June, 6,000 tons and $35,000, or $5 83 per ton. The total expense was $5 per ton for a portion of the time at least, the cost of transportation by car being 72 cents. In 1864 the Pine Tree yielded $67,940. In December, 1863, when the ore paid $29 to the ton, the refuse tailings assayed $16 to the ton, showing a great waste. There is a large quantity of good ore now in sight in the mine.

The particles of gold in the Pine Tree quartz are extremely fine, usually so small as to be invisible to the naked eye. As a consequence it is very difficult to catch the metal in the process of amalgamation, and Professor Ashburner, in a report made in May, 1864, said that 70 per cent. of the gold in the quartz worked in the Benton mills was lost, or, in other words, only 30 per cent. of it was saved. This fact was ascertained by "a series of assays upon the tailings which have been allowed to run to waste."

In the same report he said, "I think the Josephine vein, as it is called, is nothing more than a branch from the Pine Tree, and the two systems of workings, as they have never been carried on in connection, have given rise to two mines." Dr. J. Adelberg made a report on the mining property of the Mariposa grant in August, 1860, and in it he said:

These two veins run parallel on the whole, but sometimes a little diverging, sometimes a little converging; sometimes running together and forming two distinct divisions of one vein. They belong to distinct geological periods, the Pine Tree being earlier and the Josephine of more recent formation. The ores of both veins are very distinct, the older vein bearing, in those depths now laid open, mostly oxyds and carbonates, (among which the blue and green carbonate of copper is very characteristic,) and the Josephine, or more recently formed vein, bearing the iron and copper as sulphurets only. The eruption of goldbearing quartz has formed here veins which are equalled in extent by no other known goldbearing quartz vein.

Messrs. Garnett and Wakelee, who examined the Pine Tree and Josephine mines in May, 1863, expressed the opinion that they did not contain any considerable body of ore then in sight to pay by the modes of amalgamation in use at that time, and the only hope for making these mines "an active element of production instead of a consuming expense" lay in improvements in the system. of working the ores.

JOSEPHINE.—The Josephine mine is on a mountain side, 1,600 feet above the level of the Merced river. The vein runs northwest and southeast, and dips to the northeast. Professor Silliman says it is a contact deposit between serpentine and shale; but Mr. Kelten, who has been a superintending miner in the Josephine for more than ten years, says that in some places there is green stone, and in others slate on both sides, and it is richer in the slate than the green stone. There is no gouge in the green stone. The lode varies in width from 5 to 30 feet, averaging more than 10. In those places where the vein is small the quartz is mixed with slate. The mine has been worked through three tunnels,

the upper one being 100 feet above, and the lower 180 feet below the middle tunnel or Black drift, as it is called. The drifts have been run 500 feet in the lode, and the depth of the workings perpendicularly is 520 feet.

The pay-rock has been found in seven chimneys, which are from 40 to 100 feet in length horizontally, and are separated by barren streaks from 4 to 6 feet long in the drifts. The pay chutes dip 45° to the southeast; but the dip is less. regular on the under than on the upper side of the chute. The richest deposit is found along the foot wall, and a small streak of pay is found along the foot wall in the barren chutes. The Josephine ore has usually been worked with that from the Pine Tree in the Benton mill, so that separate accounts have not been kept of most of the workings. The Josephine vein is considered a branch of the mother quartz lode, from which it separates at the Josephine mine, running northwestward nearly parallel with the main vein. At a distance of half a mile from the fork they are about 300 feet apart. Although the mine is now lying idle, miners say that there is a large quantity of $20 rock in sight.

The indigo vein, so called because of the peculiar blue color of the rock, is 4 feet wide, and 450 feet west of the Josephine mine. The vein stone is talcose, and in places is rich in gold. It is called India-rubber rock by the miners, and is difficult to break with the hammer, but tears out well when blasted. The vein has not been opened, but a tunnel has been run through it, and it has been prospected a little in spots on the surface.

MARIPOSA.-The Mariposa mine is situated on the eastern border of the town of Mariposa, on the Mariposa lode, the direction of which is nearly east and west, the dip 51° south, and the width of the main vein from four to eight feet. Near the mill the vein forks, one prong running westward in the line of the maine lode, and the other running north of west. At a distance of 300 yards from the forks, the two prongs are not more than 60 yards apart. Each fork is about 3 feet thick. The rock is a white ribbon quartz; the walls are a black talcose slate. There is but little gouge, and the quartz is so hard that no progress can be made without blasting. East of the fork the gold is in fine particles, and is evenly distributed through the pay chute, while west of the fork the gold is collected in rich pockets, which are separated from one another by large masses of very poor quartz. These pockets contain almost invariably arseniurets of iron, accompanied by pyrites. The presence of these minerals is considered a certain sign that a good deposit of gold is not far distant. One pocket paid $30,000, another * $15,000, and numerous other sums, varying from $100 to $1,000. The great richness of the vein is proved by the facts that the decomposed quartz at the surface was worked or washed for a distance of half a mile, the ravines immediately below the lode were famous for their richness, and drifts have been run a quarter of a mile under ground. It is said before Fremont obtained possession, squatters took $200,000 from the mine. The quartz taken out in 1864 averaged $25 per ton; but afterwards the average yield was only $11. Persons familiar with the mine say an abundance of rock might be obtained to yield $12 or $15. Before the sale of the grant to the Mariposa company the mine was leased to Mr. Barnett, who paid 10 per cent. of the gross yield, a very good share, and afterwards when he was told that he could not have the property on those terms he offered to pay 30 per cent. of the gross yield, and to give good bonds. His offer was rejected, and the mine is now idle. Mr. Barnett worked the mine on a very economical plan. His stamps had wooden stems; he amalgamated in arrastras, and his mortar was fed from a hopper or self-feeder. Little hand labor was done in the mill in the daytime, and none at all at night. Indeed, everybody left the mill at supper time, and it was allowed to run without supervision till morning. The quartz was taken out under Barnett's directions, who having spent many years at the place was thoroughly familiar with it; and before going to the mill, all the barren pieces were rejected. It was supposed that the mine would pay better if it were worked on a larger scale, so the mill that had

*

stood at the Green Gulch mill of 40 stamps was moved to the Mariposa mine in 1864, in accordance with the recommendations of Professor Ashburner. Professor Silliman, in a report made in May, 1864, said:

I feel convinced that the Mariposa vein is, on the whole, the most remarkable auriferous vein yet developed on the Mariposa estate, and if the half which is believed of it by those who know it best should prove true, it will alone almost sustain the estate. The mill now erecting in Mariposa creek is the same which has been removed from Green Gulch, where, as it proved, there was no further use for it. Mr. Ashburner having examined and reported approvingly on this removal, I have not felt it needful to re-examine the evidence, the decision undoubtedly being a wise one. The fault of the other mills (except the Princeton) of being set too low has been remedied here, and with a well-considered system of amalgamation, there can be no doubt that excellent results will be arrived at in working the mill in its new and well-chosen position, nor can there be any doubt that the mill will receive an ample supply of quartz to engage it fully in crushing.

The gross yield of the mine in 1864 was $84,948; but there was no profit, and among the intelligent miners in the neighborhood there is much doubt whether enough pay quartz could be obtained to keep a 40-stamp mill going.

Messrs. Wakelee and Garnett in their report on the grant say:

The Mariposa vein we examined more particularly, as it has been quite celebrated for the extraordinary richness of its pockets of massive gold. The vein consists of a main trunk and two branches. It is in the latter that these deposits have been found. They have not been worked upon any regular system, but have been much burrowed into by different parties in quest of these rich pockets. The quartz itself is almost entirely destitute of any trace of metal, and its value seems to consist entirely of these massive deposits. It is needless to add, perhaps, that from this peculiarity it furnishes a very uncertain basis for any extensive system of mining. The main trunk of this vein differs from its branches, and the quartz found in it is uniformly charged with the metal. The ores yield, according to the best information we could obtain, about $16 per ton.

GREEN GULCH.-The Green Gulch mine, in the vicinity of the Princeton, has been explored by a shaft 200 feet deep, and by drifts running 400 feet horizontal, and the conclusion is that the deposits of auriferous quartz are not sufficiently near together to pay for working. The vein is about three feet thick, but the quartz is mixed in places with slate, which reduces the yield to a point so low that there is no margin for profit. Some rich bunches of rock have been found, and under the encouragement given by them a 40-stamp mill was erected, and new explorations were undertaken; but the rich bunchies were too far apart, and the mill was afterwards removed to the Mariposa mine. The yield of the Green Gulch mine in 1864 was $19,509. In December, 1863, while the rock was yielding $38 per ton, an assay of the tailings showed that they contained $6 50 per ton.

OTHER MINES ON THE MARIPOSA ESTATE.-The Oso mine, half a mile from Bear valley, is in a very narrow vein of decomposed talcose matter, running across the slates. It was very rich near the surface, and according to rumor the sum of $400,000 was taken from a shaft 50 feet deep and 7 feet long on the vein. No work has been done at the place for years..

The New Britain or Missouri mine is two miles northwest of the town of Mariposa. The vein averages about two feet and a half thick, runs cast and west, dips to the south, and can be traced on the surface by croppings for four or five miles. The vein stone is a soft white and yellow quartz, which breaks up like slaked lime when exposed to the air. The walls are of hard black slate. The only pay chimney which has been worked dips to the east with an angle of 50°. The quartz in this chute has been taken out to a depth of 80 feet, and it contained a number of very rich pockets, one of which was taken out by Mr. Barnett, and yielded $52,000, at an expense of $5,000. In one day and a half he took out $9,000. Professor Silliman says it is a "very promising vein."

The Mt. Ophir mine is on the mother or Pine Tree lode; has been worked extensively, and never rivalled the Princeton, Pine Tree, Josephine or Mariposa mine in the amount of production. The yield in 1864 was $12,540. The Mt. Ophir mill has 28 stamps, now idle.