in gold; total, $329 56 per ton. This is the only sample from the entire district which has come under my notice showing an available quantity of gold.

D. A sample of azurite, apparently not carrying silver, from the outcrop of the St. Louis mine, yielded $106 81 in silver.

In order to acquire a good insight into the value of the ores of the district as a whole, from twenty-seven to thirty mines were visited, and the ores sampled as they occur, regardless of assorting. An average sample taken from all the samples thus obtained assayed $68 52 per ton silver as an average for the entire district. By proper assorting this yield can be raised to $143 91 per ton, as will appear below.

The following is a list of the assays made, giving notes on the veins from which the samples were taken.

I. Galena ores of Cerro Gordo:

1. Sampled 8 feet ore-width; much vein-matter; about ore to waste; from Freiburgh No. 1 mine; assay, $25 12.

2. Sampled 3 feet ore-width; about waste; easily assorted; some copper; from San Felipe mine; assay, $12 56.

3. Sampled 2 feet ore-width; about ore, waste; containing no copper or antimony; from Union mine; assay, $25 62.

4. 6 feet ore-width; about ore, waste; some copper; no antimony; from San Aberlino mine; assay, $54 97.

5. 2 feet ore-width, in a vein 15 feet wide; about ore to waste; contains some antimony and very little copper; from Union mine; assay, $91 10.

6. 4 feet ore-width; very ferruginous; hard to assort; traces of copper; from Front mine; assay, $58 11.

7. 1 feet ore-width; ore to

waste; galena in spots; no copper; hard to assort; Guaymas mine; assay, $36 23.

8. 16 feet ore-width; very ferruginous; can be easily assorted; 3 ore, waste; from Union mine; assay, $45 55.

9. 17 feet ore-width; ore in seams; ore, waste; can be easily assorted; the only thing accompanying the galena are very soft oxides of iron, cemented together by an argillaceous mass; from San Felipe mine; assay, $12 56.

10. 6 feet ore-width; no antimony or copper; about ore, waste; the ore occurring in pockets; from Freiburgh mine; assay, $43 98. 11. 4 feet ore-width, in a vein 12 feet wide; ore, waste; not so easily assorted; from Asteroid mine; assay, 842 46.

12. 14 feet ore-width; an average throughout all the stopes of the Union, Front, and Freiburgh mines; waste, ore; assorted by hand, but not very carefully; assay, $100 53.

13. 12 foot ore-width; Queen City mine; the vein is throughout 7 feet wide; can be assorted in extracting the ores from the mine easily toore to waste; assay, $84 82.

II. Copper ores of Cerro Gordo:

1. 8 feet ore-width, on outcrop; only stains of malachite visible; mine not developed; cannot be called ore; sampled as a prospect; from Abundancia; assay, $6 28.

1

2. 2 feet ore-width in vein 24 feet wide; mostly malachite and antimonial ores; easily assorted to ore, waste; from Abundancia mine; assay, $80 10.

3. 2 feet ore-width; highly oxidized ore; mostly copper and antimonial ores; waste, ore; vein 10 feet wide; San Ignacio mine; assay, $316 14.

4. 7 feet ore-width; some galena; not refractory ore;ore, waste; from San Ignacio mine; assay, $161 78.

5. 8 feet width of the entire vein of No. 4; San Ignacio; can easily be assorted to ore waste; from poor portion of the mine; assay, $31 42.

6. 5 feet width of vein; sampled as it would be taken out before any assorting could be done; ore in spots; no galena; can be assorted easily by hand, say ore, 1 waste; from Grand Poder mine; assay, $10 98.

7. 4 feet vein-width; docile ore; little lead, say ore waste; from the Guaymas mine; assay, $47 13.

8. 23 feet ore width, being two separate pay streaks in a vein 6 feet wide; does not require much assorting; contains some antimonial ores; from Candelaria mine; assay, $105 39.

9. 3 feet ore-width, vein 4 feet wide; contains considerable galena, is assorted to about ore waste; contains antimonial ores; from San Lucas mine; assay, $108 06.

10. A vein 3 feet wide; San Benito mine; about ore waste; no galena. This is a sample from the mine and from the dump which was assortedore waste; ore can be amalgamated, and may be called an average; assay, $106 83.

11. A vein which is 27 feet wide at the outcrop, showing about 10 per cent. of galena and silver copper-glance, very sparingly distributed throughout the vein. One ore-seam is 18 inches, widening and narrowing along the outcrop; from Abundancia; not developed much; assay, $7 85.

12. 33 feet ore-width; mostly oxidized ores; vein is 5 feet wide; easily assorted, to about ore, waste; from Asteroid mine; assay, $105 75.

13. Several ore-seams, from 2 inches to 1 foot in width, on a vein 6 feet wide, making in all probably about 26 inches of ore width; from Fermin mine; ore fit for wet process of beneficiation; assay, $115 15.

14. The ores from the Robinson, Chevall, Sacramento, Reindeer, Omega, San Benito, Tresilos, Alpha, San Louis, and Queen of the West, were also sampled. But little work has been done on these mines. They are situated in the southern portion of the district. An average assay of $42 11 per ton was obtained. The ores of all these resemble one another very much, and none of the veins exceed 6 feet in width. All the foregoing samples, taken together, give an average of $68 52 silver per ton. They were taken with the object to get at the real merits of the mines as a body, with little assorting. They can certainly all be assorted to ore to waste, with a loss of 25 per cent. of their actual assay value. This would bring the average to $154 17 per ton; and even if we admit a loss of 30 per cent., the silver value would still be $143 91. Much of the success of the district depends upon the careful classification and assorting of the Those ores bearing much gangue matter, and at the same time docile, (highly oxidized,) can easily be assorted from the others, and reserved for wet amalgamation, as, for instance, the ores from the Grand Poder, Candelaria, Valenciana, Tresilos, Mejicana, Portuguese, and San Benito mines. Those veins carrying refractory ores, by far the majority, must be freed from the accompanying gangue matter as closely as possible and beneficiated by smelting. This dressing is rendered easy by the great difference in the specific gravity of the ore and the barren rock. The most prominent mines are, the Union, San Ignacio, Freiburgh, San Felipe, St. Lucas, and Belmont; about sixty mines are located and prospected. I have pointed out already that the mines can be divided

ores.

into two classes, and I shall therefore describe one belonging to the so-called "lead mines," and two belonging to the "copper or silver mines," which will suffice to impart an intelligent idea of all the mines of the district.

San Ignacio, (Copper and silver mine.)-The vein has a general direction of east 100 south, dipping southwest. It is embedded in compact limestone, has crystalline limestone predominating as vein-matter, and some quartz is found subordinately. The surface workings show a very irregular vein; the walls are disturbed, and no definite line of contact can be established, which makes the vein appear 50 to 60 feet wide. Work was at first commenced on the outcrop by a cut on the side of the hill, following the vein nearly 100 feet on its course, and for 60 to 70 feet in depth. An incline of 40 feet has been sunk, and a tunnel of 270 feet length cuts the vein 65 feet below the surface work, or 175 feet below the outcroppings. The incline and tunnel show the vein improving in depth; its width in tunnel is 20 feet from the hanging wall (siliceous slate) to the foot wall, (compact bluish limestone,) and both are plainly discernible; the dip is 600 southwest. The ore in the surface workings occurred in irregular masses, seams, and pockets, varying from to 10 tons in bulk, divided by slate and limestone; while in depth in the incline, it is found in more regular seams, and partakes of a more uniform character, ranging in width from 3 to 8 feet.

The ores from the mine belong to the second class, (copper ores,) although nearly all the described ores of the district occur in the vein; galena appears in the southern portion of the mine, but not in sufficient quantity for smelting operations without further addition of lead ores. Fifty feet below the mouth of the incline an assay of $178 32 in silver per ton, from an ore seam of 13 feet in width, was obtained. At the time of Mr. Luckhardt's visit nine men were employed by the company, raising, daily, from 3 to 4 tons of ore to the surface, of an average value of $280 per ton. The capacity of the company's reduction works being 2 tons, daily, the product of the mine was limited to 4 tons. The appearance of the work done so far allows a daily extraction of 12 tors, and the opened ground shows about 1,200 tons of ore in sight of the above value. Local circumstances have thus far prevented the beneficiation of second-class ores, (from $80 to $50 ore,) of which there are over 2,000 tons now lying on the waste-dump.

Capital is only very lately finding its way to the district, and very sparingly. All operations done so far on the San Ignacio, and, in fact, on all the veins, have been only on a small scale, the district being but in its infancy, a state when all kinds of work are seldom carried on without great obstacles. But it has so far rewarded the owners handsomely for their outlay; and wherever it has been persevered in it has generally proven that great wealth is actually in the mines. In the vicinity of the San Ignacio are located the Bandera, La Primera, San Francisco, Alpha, Franklin, Asteroid, San Thomas, Coronel, &c., and other smaller veins, which bear not only in their formation but also in their ores much resemblance to the San Ignacio; but none of them have been explored sufficiently to reveal their absolute merit. All have yielded rich ores in small quantities.

San Lucas mine.-This inine is situated 6 miles north of the San Ignacio, and belongs also to the second class, namely, copper and silver mines. The croppings (quartz) dip 650 north, in limestone, and run east 50 south. Near the surface the vein shows 6 feet in width, containing several narrow and poor seams and spots of ore, and does not look promising. An incline of 94 feet has been sunk on the footwall,

and the vein followed 80 feet on its course, where ore has been found and extracted in bodies from 3 to 7 feet in width and 10 to 25 feet deep-the vein having widened to 13 feet from wall to wall. The lower workings show a decided improvement in the quality and quantity of the ore. The average of an eastern drift, in ore 5 feet wide, at 69 feet depth, was $58 83 in silver. The ore contains from 7 to 10 per cent. of galena, and some antimonial ores; gray copper and silver-copper glance predominate. I met with nests and bunches of ore assaying $300 per ton; and the ore lying on the company's dump, as it is being sent to the smelting-works, now averages $115 30 per ton. The mine has been very irregularly worked thus far. It is, like many others, very favorably situated for tunneling. A tunnel of 600 feet in length would meet the vein 350 feet below the outcrop; and I believe that with judicious management the mine could be made to yield 25 tons of $100 ore daily, with an outlay of $5,000, while the present yield does not exceed 6 tons daily.

In the vicinity are, among many smaller veins, the Wittekind, Belmont, Abundancia, Candelaria, San Miguel, Enterprise, Abellino, Virginia, Guadalupe, Guaymas, and others, some of which carry so little galena ores that they can be beneficiated by wet amalgamation. They all resemble the two veins above described, both in gangue and ores, yielding from $45 to $150 in silver per ton. Their widths vary from 5 to 40 feet, and thus far but little work has been done on them-just sufficient, in many cases, to comply with the laws of the district in order to hold possession, and I am of the opinion that, in all probability some of these mines, when once worked, will yield abundantly in ores, and will by far exceed the Ignacio and St. Lucas, which are already proven good mining property and looked upon as among the best in the district. One of my reasons for this opinion is that actual work has, in most instances, shown an improvement in depth both in quality and quantity. Another is the fact that the ore exists in bunches and pockets, which are detached from one another by barren vein-matter, or by intrusions of masses foreign to the vein itself. This leads me to expect more ore and larger bodies where less irregularities exist, which will be the case the deeper work progresses on the veins. These ore bodies are always found to be larger where much bulk of vein-matter exists than where a vein is narrow, and some of the above-named veins are very wide.

None of the described mines carry sufficient galena in their ores to fit them for smelting alone, neither can the majority of the ores be amalgamated; and as much attention has therefore to be paid to the lead as to the silver-copper mines.

The greater number of the veins located near the center of the district are so-called "galena ledges," as, for instance, the Union, San Felipe, Freiburgh, Nos. 1, 2, and 3, Santa Maria, Buena Vista, Knickerbocker, and others, some of which seem to be located on one and the same vein. I found three distinctly separated veins of very large dimensions, besides several smaller ones of little importance, on the hillside where all the above named claims are situated. With very few exceptions they are of a very uniform character, and in describing one all will be described.

The Union vein has a general north and south course, is imbedded in a compact grayish limestone, dips west 620 with the horizon, and carries calespar as predominating vein-matter. Near the surface its width cannot be well established; it resembles a mass of ore thrown together with boulders of country rock to a width of 50 to 60 feet; only the foot-wall is visible in a few places. Several mining companies have located claims on this vein, and have attacked it from the surface to a depth of 130

feet in some places. The Santa Maria tunnel has cut the vein 200 feet below the surface. The lower workings show more regularity in the vein; its width can be called 23 feet, but in one place I saw it 40 feet; the foot-wall can be well seen, the hanging-wall can only be found well defined in places. It carries the ore in bodies of various sizes and dimensions, but they all have an inclination from north to south, and seem to improve southward. The ores are chiefly argentiferous galena; copper occurs only in very small quantities, and only near the surface. Iron pyrites, in various stages of decomposition, is a steady companion of the ores; it only exists where ore is found, and it is only where it is completely converted into peroxides that it has penetrated the vein-matter so as to hide the original texture and form entirely. This vein has shown thus far three separate ore bodies, which have yielded to the various companies at work on them probably over 21,000 tons of ore, of an average value of $120 per ton. It has been attacked by two shafts and three tunnels, and is at present yielding all the Forty feet below the necessary ore to supply three reduction works. outcrop an average sample of the vein, here 30 feet wide, was taken regardless of waste, and $36 23 in silver per ton was obtained, and 87 feet below the outcrop the vein, 20 feet wide, assayed $58 11 per ton. There are two phenomena which speak well for the future of the vein. The supposition is, that all veins change in depth, and especially when This change first shows itself in nearing the so-called water level. those ores which are easily decomposed, and, requires the attention of the miner, as it influences the percentage of precious metals which the vein may carry in the croppings or surface workings. In the vein in question here we have argentiferous galena ores, accompanied principally by iron, and we find that a change has made itself already apparent at a depth of about 150 feet below the outcrop, namely, the galena has changed from a fine crystalline structure to coarse crystals, and the hydrated oxide of iron of the upper workings begins to resume its original state, i. e., that of sulphuret of iron. The percentage of silver in the ore has, however, remained the same, and from this we may infer that it will probably remain so to a considerable depth.

On the surface the vein shows much irregularity. The intrusions of barren rock, foreign to the vein, which divide the ores in bodies, are very frequent. As depth is attained on the vein these intrusions still exist, but not in such multitude. The ore lies more regular, and we may expect to find more regularity in the occurrence of the ores as these intrusions decrease in depth.

A careful examination of the entire hill and nearly all the galena mines situated on it did not detect anything of sufficient import to destroy the opinion formed, namely, that a vast amount of argentiferous galena may be expected from them when they are fairly opened.

General remarks on mining and reduction.

This has been

A. Mining. The larger portion of the mine owners at Cerro Gordo are in want of sufficient capital to open and explore their mines and to fit them for the extraction of large quantities of ores. the main cause that mining has been carried on without a system. Many mines have only the necessary work done on them to make their titles good. Some of the mine owners seem to have worked solely with the object to extract a few tons of rich ore for sale, in order to produce the necessities of living, while others extract larger amounts of ore and try to smelt them under great disadvantages at or near the mine.