These hundred feet is the depth of the holes in the shaft referred to. are then filled up with sand. When the drilling is over the machines are removed, and blasting commences. Four feet of the sand is removed with a common sand-pump from the upper part of each hole, and one foot of clay-tamping is put in. This leaves an ordinary threefoot hole, which is blasted out, (with dualine or giant powder.) The interior holes are fired first, and afterwards those which have been bored in the corners and along the sides of the shaft. This process is repeated until the holes have been "used up," and the shaft is down to the bottom of the borings. If additional depth is desired the machines are set at work again, and a new set of deep borings is made. The sides and corners are found to be remarkably true and smooth. The drills here used are not annular, but have full convex heads in which the diamonds are set, and which are perforated to permit the passage of water. A stream, passing down through the tube used as a drill-rod, and up on the outside of this tube, keeps the hole clean and the drill-head cool. The expense and the time required for sinking a shaft are by this method both greatly reduced. The average rate of drilling has been 34 feet per day, the maximum thus far for a single machine being 67 feet in 8 hours. The shaft has been blasted out at the rate of over 25 feet per week. Mr. M. C. Bullock, engineer of the American Diamond Drill Company, 61 Liberty street, New York, is one of the patentees of the process, and Mr. Henry Pleasants is the engineer in charge of the work. The Blatchley drill. This drill, which was briefly noticed in my last report, is rapidly growing in favor. It has but recently been perfected, and is unlike any other rock-drill, both in principle and construction. It operates by percussion, and the blow is like that of the churn drill. gives from three to six hundred blows per minute of as great a force as the drill-point will sustain. This is a greater degree of speed than has heretofore been obtained; consequently it drills more rapidly than it has been possible to drill before this machine was invented. It has an automatic feed, whereby the drill is fed forward just as fast as it cuts, and no faster; in hard rock, slowly; and in softer rock, more rapidly, precisely as it is required for its most efficient operations. At each blow the drill makes a part of one revolution so as to strike in a different place at each blow, as a miner turns his drill in hand-drilling. It contains only about one-fourth as many pieces as other power-drills, and does not depend for its action on any springs or pivots, liable to get out of order. It has no steam or air-engines attached to the drill with delicate parts and nice adjustments to be destroyed by the concussion and recoil of the blow. The construction is such that the connections between the drill and the driving machinery cease at the moment the blow is delivered, so that there is no recoil on the machine. On this account it can be set up in a mine on a plank, and does not require a car and heavy fastenings to hold it in place when in operation. It is estimated that a miner working at ordinary speed strikes twenty blows per minute; but this machine will strike five hundred in the same time, all of equal force, and all precisely square against the rock, thus doing the work of thirty men; and as four or five, and even more of these machines can be run in an ordinary-sized drift or tunnel, at the same time, the work of a hundred men can be done in the space where only four could work by the old method of hand-drilling. In form it is composed of two cylinders, the shorter and larger one being placed on the top of the other. In the small size, the large cylinder in which the drill moves is twenty-two inches in length and three inches in diameter; it has flanges on the bottom by which it is secured when in operation. The other cylinder is seven inches long and five in diameter, and is secured on the top of the other at one end and parallel with it, the two being arranged somewhat like the barrels of an opera-glass. The upper cylinder revolves and communicates a reciprocating motion to the drill. The length of the whole machine, excepting the drill, is twenty-two inches, height eight, and the width five inches, excepting the flanges, which are ten inches; and the weight is seventy-six pounds. The drill is of the length required to reach the bottom of the hole, and may be of any length, from one foot to six feet or more. This small size enables it to be used in any tunnel, shaft, or place in a mine where a miner can enter, and is so arranged that it will bore a hole in any direction. It can be put in operation in a tunnel in a few minutes after a blast is exploded, and before the broken rock is removed, and while it is running the débris can be taken away. In a small space one man can operate one machine, but in a quarry where there is sufficient room he can manage several. It requires no more skill to run it than is required to operate a sewing machine, and any miner of ordinary intelligence can learn to run it in a couple of days. It takes from onehalf to one horse-power to run it. The motive-power can be steam, compressed air, water, or horse-power. In an ordinary-sized tunnel a tread-mill horse-power can be placed on one side of the track in the tunnel, and be moved in as the tunnel is driven forward. Where a steamengine is at the surface, power can be taken from it to operate in the deepest and most extensive mine. Where a high fall of water can be obtained, a small wheel attached to the drill gives a very convenient power. This machine has not been completed for a sufficient length of time to have worn out any of them, but the first one made has drilled nearly two thousand feet, and is apparently as good as ever. All of the parts of the different machines are alike, so that one can be substituted for another, making it very simple to repair, in case a machine should get out of order.* The Von Schmidt drill, noticed in my report of 1871, is being constructed for running a tunnel through the Sierra Nevadas for the Lake Tahoe Water Company, and though probably of great utility, its merits have not yet been tested by actual experiment. The sale of mineral lands and quartz ledges.-The investment of large amounts of foreign capital in the purchase and development of our gravel mines and quartz ledges is to a great extent due to the operation of the various congressional acts throwing the mineral lands in the market for occupation and purchase, whereby title may be secured, instead of holding mining property, as formerly, subject to the insecure tenure of local mining laws and usage. The following table will show the extent to which our miners have availed themselves of these acts: *This account is taken from statements made in behalf of the inventor. I do not wish to discredit it, but merely to say that I have not verified its claims by personal examination.-R. W. R. List of mines in California surveyed from October, 1870, to January, 1872. Total claims surveyed, 72. Placer, 34; quartz, 33; quicksilver, 4; copper, 1. Many of these have been patented, and on the others patents are pending. Statistics of quartz-mills and mining ditches.-By the laws of California it is made the duty of the county assessors to return each year to the surveyor general of the State, among other statistics, a list of the quartz-mills and mining ditches in their respective counties. This duty is very imperfectly and carelessly performed, as will appear from an examination of the returns for the years 1867-'68 and 1869-'70, on page 15 of the Mining Commissioner's Report for 1870, where the errors in these tables are pointed out and commented on. I believe the following table, compiled from the surveyor general's report for 1871, though evidently more accurate than the two others referred to, is open to much criticism, and with this explanation I give it for what it is worth. It will be observed that there are no returns from two of our leading quartz-mining counties, Tuolumne and Plumas. cording to Langley's Pacific Coast Directory, the former of these coun.. ties has 41 mills, with an aggregate of 445 stamps, and the latter 19 mills, with an aggregate of 233 stamps. Returns from those counties would have materially run up the total under the heading of "tons crushed," and shown, by comparison with the table of 1867-68, a great increase in this branch of mining. The table of 1869-'70, (page 15, report of 1870,) is so manifestly erroneous under this heading in the amount credited to Placer County, as to be useless for comparison. Ac Table of quartz-mills and mining ditches, as reported by surveyor general of California, for the years 1870 and 1871. Great discrepancies exist between these returns and the list prepared by Mr. Langley for his directory, published in last year's report, (pages 463-469.) For instance, Langley gives Amador County 36 mills, or 9 more than the surveyor general's report; Mariposa County 29 mills, being 5 less than the surveyor generals report. He gives Nevada 74 mills, to 60 in this table, and Placer County 32 mills, while the assessor's returns show only 14. So in Sierra County, Langley 36 mills, and the assessor returns only 21. I cannot reconcile this difference except on the hypothesis that the assessors have not returned some mills which have not run for several years, while Langley has kept them on his list. THE SOUTHERN MINES. The term "southern mines" is an indefinite one, but is generally understood to embrace the country between the Cosumnes River on the north and the Chowchilla River on the south, a distance of one hundred miles, and include the counties of Mariposa, Tuolumne, 'Calaveras, and Amador. In width the mineral belt extends from the eastern edge of the San Joaquin Valley to an average altitude of 2,500 on the Sierras, a distance of forty miles east and west, thus embracing an area of 4,000 square miles. This region of country was the scene of the earliest mining operations in California, as the surface placers were here more accessible and productive than further north; and within its limits are found the once populous and thriving mining towns of Mokelumne Hill, Columbia, Sonora, and Mariposa. Its population, as estimated in 1851, by Abbé Alric, then parish priest of Sonora, was not less than 50,000, nearly all of whom were engaged in mining. This extensive territory is cut and eroded to great depths by four principal streams, running from east to west, and crossing the course of the ancient streams, viz: the Merced, Tuolumne, Stanislaus, and Mokelumne rivers, which, with their tributaries, have acted as distributors of the auriferous deposits, and carried the gold from its original place of deposit to the banks and bars which yielded such enormous sums during the early days of mining. The waters of these rivers have since been diverted into ditches and flumes for mining purposes, and their principal tributaries run dry in the summer, giving the country a parched and desolate, appearance during the greater part of the year. Within the area above described, scarcely a square mile can be found in which, even at this late day, a "prospect" cannot be obtained, although placer mining as a business has ceased to yield large returns, except in the opening of new ground at points where water has been lately brought in, or in the development of the ancient channels. Superficial placer, as well as river and bar-mining may be considered as practically exhausted, although operations are still prosecuted, on a small scale, on the limestone belt, and on the rivers during the short season of abundant water. The principal mineral resources of the southern mines, at the present time, are vein-mining in the gold-bearing quartz belts and gravel-mining on the ancient channels. Within the limits of this region are found the rich and extensive copper belt, of which the town of Copperopolis is the central point; the Mother lode of California, one of the most thoroughly developed veins of gold-bearing quartz in the world; and a system of veins running in the granites, high up in the Sierras, which are comparatively undeveloped. Other systems of veins, unconnected with either of the above, and on which extensive and profitable mining operations have been carried on for several years, occur near the contact line of the slates and granites. All these lodes and systems of veins have a general course of northwest and southeast, and are evidently true fissures. At many localities, among which we may instance Bald Mountain, east of Columbia, in Tuolumne County, smaller veins occur, with an east and west course, generally in the slates. This latter class have the peculiarities of gash-veins, most of them "pinching out" at a depth of from fifty to one hundred feet, and being generally richest above the water-line and near the surface. This class is known as "pocketveins." Although many so-called pocket-veins exist near to and parallel with the Mother lode, as at Angel's Camp, Calaveras County, where this class of mining is extensively carried on, it is generally believed they are outlying "stringers" of the main lode. Copper mining.—An extensive belt of copper veins exists in the slates in the western part of Calaveras and adjoining counties, at an elevation above sea-level of about 1,000 feet. These veins were discovered in 1861, and subsequently developed to a depth of 500 feet, at Copperopolis, Calaveras County, maintaining their character for width of vein and grade of ore at lowest levels opened; but in 1867 operations ceased in consequence of the depreciation in the price of copper, and have not since been resumed. Up to the cessation of work the copper mines of California (the most productive of which are in the southern mining region) had exported 68,631 tons of ore and 847 tons of metal in bars. Up to that period nine smelting-furnaces had been erected in California at an aggregate cost of $236,000, all of which proved financial failures, and a majority of which were technical failures. When the copper mines of |