gard to the present financial position of this company, and as these favorsults were only obtained by economy in the management and skilful nt of the ores, which yield far less than the average of California quartz, give a condensed statement of their operations for the last thirty-six years. ective capital of the company is £129,000, divided into 1,100 shares, and as been paid in dividends £756,245, or £68 15s. per share. There is on reserve fund of £41,506, and the value of the property of the mine is ed at £209,743, showing a total profit during the thirty-six years' work£1,007,494. The produce of the mine during this period has been 2,480, and the expenses £1,894,986, or 65.3 per cent. of the gross reThe average yield of the ore raised and treated has been at the rate of vas per ton of 2,240 pounds. This is equivalent to about $8 50, or reduced to the usual Califorinia ton of 2,000 pounds. The yield for the -ee years has been as follows:

8, 5,787 oitavas per ton, at $1 89 per oitava, $10 94; 1864, 4,827 oitavas , at $1 89 per oitava, $9 12; 1865, 5,479 oitavas per ton, at $1 89 per 0 36.

ng this period of the total amount of gold contained in the ore there was
ed the following percentage:

3, 72.35 per cent.; 1864, 75.52 per cent.; 1865, 77.95 per cent.
various processes heretofore employed in California for amalgamating
ave been of the simplest possible description, and, although probably in a
y of instances where the gold was clean, free and uncombined with the
rets of iron, lead, copper, and zinc with which it is so frequently associ-
hese methods worked well, and the erection of expensive machinery,
would necessitate slower working, would not be warranted by the facts
case. Yet it has often happened, particularly in those mines situated
he course of the "Great Vein," that quartz which has been known to con-
ld in paying quantities has not yielded when treated in the mill more
fficient to pay expenses, and sometimes has been worked at a loss. This
appear to be chiefly owing to the inefficiency of the apparatus employed
ect and save the gold, which may have been in a very fine state of sub-
n, or coated with a thin film of oxide of iron arising from the decomposi-
pyrites, which prevents the mercury from adhering to it without the use
e vigorous mechanical or chemical means than are usually employed.
and near Sutter creek, in Amador county, there are several very excel-
ines situated upon the course of the "Great Vein." The most noted of
s that belonging to Messrs. Hayward & Co., and known as the Eureka.
ine has been worked for about eleven years, and has produced probably nearly
ch gold as any other in California. The quartz has never averaged very
and the principal production has been from ores of a low grade, not yield-
obably more than from $10 to $15 per ton. The mine is situated at the
on of the slates and greenstone, the hanging or eastern wall of the vein
of the latter material, hard and compact, while the foot-wall is of a dark
ft argillaceous slate. The depth of the lowest workings is now 1,213 feet
incline of the vein, which makes this shaft the deepest in the United
The length of the underground workings is about 600 feet, and at the
and south extremities the vein thins out rapidly. The richest portion
vein appeared to be at a depth of between 1,000 and 1,100 feet, where
artz is said to have yielded nearly $30 a ton. The great depth attained
mine shows conclusively that we cannot draw any general conclusions
egard to exhaustion of quartz veins at an inconsiderable depth. It is true
nearly every quartz mine of California the outcrop has been found to be
richer than the main body of the vein at even a short distance from the
e, but it must be borne in mind that many of the veins, and in fact a
ity of them, contained gold associated with various mineral sulphurets,

which were decomposed and the gold infiltrated down for some distance the surface of the ground, causing the upper portion to appear abnormally Thus the gold contained in the first few feet of the vein may be the re the degradation of many tons of quartz and the decomposition of a large tity of sulphurets. It is only by taking the results afforded by the trea of quartz during a series of months that anything like a correct average value of the ore can be obtained, and although this Eureka mine has pro yielded as regularly as any other prominent mine in California, it has bee ject to great irregularities, and frequently the quartz has barely paid exp The popular idea that mineral-bearing veins grow richer as they are w upon in depth, is a fallacy, and has no truth either in theory or fact; n we say that true veins, as distinct from veins of segregation and mineral de grow poorer as we proceed downwards. I do not suppose there is a m ferous vein in the world that is equally rich for any considerable distance, lengthwise or up and down, and the valuable portion is almost alway limited in extent compared with the main body of the vein. Some of the veins of Mexico, which have produced such enormous sums, have been for miles, and on their course have furnished many valuable mines, but the greater proportion of the vein has been barren and unproductive. The stock vein of Nevada, which has already produced upwards of $60,0 worth of bullion, has been productive only over about one-seventh of its ex length.

These remarks apply with great force to the gold quartz veins of this The ore exists in bunches or else in shoots or chimneys which cut the a the vein at every conceivable angle between the horizontal and the vertica these are always less than the length of the vein itself and sometimes t width also.

It frequently happens that these ore-shoots have distinct terminal line in these cases the experienced miner is enabled to select his ore and av tracting that which he knows is too poor to pay. On other occasions, ho it would appear that the gold is distributed without any regularity and rently in the most capricious manner. When we consider the richness veins, the length of time that some of the mines have been worked, a amount of gold annually produced, the most important quartz mining re California is without any doubt that of Grass valley, in Nevada county. mines have been worked uninterruptedly since 1851. It is true there hav periods when the interest was more than usually depressed and, several mines, which are now regarded as being among the best, were thought to hausted, and abandoned for the time being, but in many instances wher was resumed new bodies of gold-bearing quartz were opened up which rich and valuable. The veins in this district, and particularly those whic been the most productive, are noted for their narrowness as well as for th ness of the quartz. They are incased in a hard metamorphic rock, and penses of mining are, as a general thing, higher here than anywhere California, amounting, as they do in some instances, to from $20 to $26 p Within the last fourteen years the total production from the quartz mines Grass Valley district has not been far from $23,000,000. The most vein has been that situated upon Massachusetts and Gold Hill, which alo produced more than $7,000,000 worth of gold during this time from a lode will only average a foot or fourteen inches in width.

The "Eureka" is another prominent and leading mine in this vicinity. great feature of interest connected with it is the gradual improvement quartz as greater depth has been attained upon the vein, which varies in from three to four feet. This mine was first worked in 1854, and more ever since that period. About one year ago the property changed hand since that time the yield of the mine has been greater than at any pr

When this vein was first worked and down to a depth of about thirtyfrom the surface, the yield of the quartz was from $6 to $12 per ch but little more than paid expenses. Below this level the value of tz rapidly increased from $14 to $21, and at the one hundred foot quartz paid at the rate of $28; at the two hundred foot level the was about $37, and now, between the second, and third levels or three feet from the surface the average yield has been during the last four at the rate of over $60 per ton. The quartz contains from two to r cent. of sulphurets of iron, which are said to assay generally about ton, and are regarded as being among the richest in Grass valley. lphurets are worked by parties in the neighborhood, who charge $50 and return whatever gold is extracted to the proprietors of the mine. the four months which preceded the first of October the mine produced tons of quartz, which yielded $255,072 55, and the expenses of mining ing were $67,320 83, leaving as profit $187,751 72. The average the quartz during the period was at the rate of $60 33 per ton. vhole year the amount of quartz worked was 11,375 tons, which pro526,431 41, at an expense of $168,389 23, leaving as profit for the whole 8,042 18. The average yield per ton was $47 15, and the average cost g and milling was $13 75, leaving a profit of $33 40 per ton.

4.-MINING IN THE SIERRAS; MILLS, EXPENSES, &c.

Dur

as dismissing the Grass Valley district with only a brief description of ts leading mines, I do not intend to detract at all from its past, present, importance, for there is no region in California, or probably upon the oast, where, by a careful study of the numerous veins in this neighso much information could be obtained which would throw light upon -d questions relating to gold mining and the metallurgical treatment of

tz.

proceed north from Nevada county, the next most important quartz istrict is in the mountainous region round about Downieville, the county Sierra. The placer mines in this vicinity have been exceedingly rich, passed only by those in Nevada county in extent and permanence. nining, however, has received but comparatively little attention until he last few years, probably owing to the rugged nature of the country severity of the climate during the winter months.

most noted mine in this county, as well as the one which has produced gely, is that known as the Sierra Buttes. This mine is about fourteen om Downieville, at an elevation of probably not less than 7,000 feet e sea. The vein is enclosed in a hard metamorphic slate, and varies from six to thirty feet. In the process of working, the whole thickthe vein is not removed, and the richer portions, which lie next the 1, are sent to the mill. The average width of this more productive about twelve feet. The depth upon which this vein has been worked r from 750 feet, and the quartz in the lower portion of the mine is said 8 well as that taken from the upper works. Quartz from near the surhis vein was worked in arrastras as early as 1851, but the first mill was n 1853. The present owners have been in possession of the property 57, and the yield of the mine has been, during the last nine years, aptely as follows:

1

The yield of the quartz varies generally from $14 to $17 per ton, a cause of the falling off in the gross product during 1863-'64 was the great s of water, which necessitated the erection of a flume at an expense of $40, The principal expenses attending the working of auriferous quartz a cost of extracting the quartz from the mine and its subsequent treatment mill. With regard to the first no general data can be given, for the a paid for mining varies from $1 50 to $26 per ton. It is dependent up hardness of the quartz; the hardness of the country rock in which the encased; the relation which the auriferous portion of the vein bears which is barren; the depth of the workings, and finally the amount of w the mine, and whether it has been drained by adits or pumping. As a rule, however, it may be assumed that in the case of large veins, or those exceed five or six feet in width, that the cost of extraction will be from to $6, and that the total cost of mining and milling will not be more t or $8 per ton under any circumstances.

With regard to the milling expense, however, we have accurate data low, and these are not much affected by change of locality.

The mills are generally situated in close proximity to the mines, for the ence between the cost of running a steam and a water mill is almost alwa than the cost of hauling the quartz for any distance by teams. The m of nearly all sizes and capacity, and vary from those which have only three stamps to those which have forty-eight. The weight of these sta from 400 lbs. to 1,000 lbs., and they are run at a velocity varying from 50 to 80 blows per minute and fall from 10 to 14 inches. The favorite would appear to be about 650 lbs., with a fall of 12 inches and a velo from 60 to 70 blows per minute. It is generally assumed that a ten-stan with stamp of 550 lbs., falling 12 inches and striking 60 blows a minute, wil 12 tons of ordinary quartz in the twenty-four hours.

The mills which are moved by water power alone are situated either banks of rivers and streams where the water is free, or else the water veyed to them by a flume from some neighboring ditch and sold at which is generally the result of special agreement.

In the case of steam mills the fuel is always a principal item of e Wood-either pine or oak-is universally employed, and costs from $2 to and even $5 per cord. Oak, when the two can be obtained and are convenient of access, generally costs one-third more than pine and is re as being nearly twice as valuable for steam purposes. The mean am fuel consumed in the steam quartz mills of California is not far from 0.10 for each ton stamped. The prices paid for labor in the mining towns very high, and in many cases operates as an effectual barrier to the wor some quartz mines. First class miners receive from $3 to $3 50, and i cases as high as $3 75 per day, while ordinary laborers receive from $2 to In the milling of quartz the item of labor is generally from 60 per cen per cent. of the total expense. In mining the proportion which this iten to the whole cost is much greater, so that it is easy to perceive to what

uction of wages would operate in favor of the quartz mining interest

ast.

ercury that is used in the process of amalgamating is derived entirely California mines, and generally costs the miner about sixty-five cents ; very little, however, is lost in the mills when proper care is observed, tem of expense is insignificant, for it rarely exceeds six ounces for each irtz treated, and frequently falls below this amount.

erage cost of milling quartz in the various mills of California may be follows:

mills, when water is free... $1 22 per ton of 2,000 pounds. mills, when water is purchased...... 1 60 per ton of 2,000 pounds. mills........... 2 14 per ton of 2,000 pounds. ry difficult to state, even approximately, what is the present average he quartz from the California mines. It is probable, however, that it aried much within the last five years, and in 1861, taking the returns e mines which were at that time believed to be profitable concerns, it e rate of $18 50 per ton. The two extremes were a mine in Grass ich was yielding at the rate of $80 per ton, and another at Angels, ras county, where the quartz only paid $5, and was still being worked profit.

remain, very respectfully, yours,

WM. ASHBURNER,
Mining Engineer.

BROWNE, Esq., Statistical Commissioner.

SECTION 3.

TION OF GOLD AND SILVER MINING ON THE PACIFIC COAST. of yield.-2. Export of treasure from California.-3. Receipts from northern thern mines.-4. Comparison of receipts and exports.-5. Quartz yield increasing. ncertainty in quartz mining.-7. Professor Ashburner's statistics.-8. Rémond's es.-9. Pulverization of quartz.-10. Amalgamation of gold.-11. Sulphurets and tration.-12. Chlorination.-13. Gold in loose state.-14. Placers.-15. Cement .—16. Hydraulic mining.-17. River mining.-18. The Haquard quartz mine.-19. Buttes mine.-20. The Allison mine.-20. The Eureka mine.-21. Smartsville Gravel Company's mine.-22. Profits of mining generally.-23. Difficulties of good claims.-24. Comstock lode, the most productive in the world.-25. Comnining companies.-26. Quartz mills in Nevada.-27. The pan.-28. The Wheeler 29. The Varney pan.-30. Knox's pan.-31. Hepburn pan.-32. The Wheeler lall pan. 33. Estimated yield of various mines.-34. Assessments levied.-35. ould & Curry mine.-36. The Ophir mine.-37. The Savage mine.-38. The Jacket mine.-39. The Crown Point mine.-40. The Hale & Norcross mine.Imperial mine.-42. The Empire mine.—43. Productive mines of Reese river. Wield of various silver districts.-45. Improvements in silver mining.

1.-DECREASE OF YIELD.

et fact in the condition of gold mining in California is that the yield the last thirteen years has been decreasing. We know this by the t testimony of the miner, by the decrease in the traffic of crude d by the decline of the exports of gold. No record is kept of the aken from the mines, and our best evidence in regard to the producEx. Doc. 29-4