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Cullom & Co., of the Swansea Reduction Works, following suit, offered to reduce lead-bearing ores as follows:

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guaranteeing to return or pay in currency 90 per cent. of the silver, and from 70 per cent. to 80 per cent. of the lead, depending upon the amount of zinc-blende and other deleterious substances in the ores.

Subsequently, I believe, the German works came down as low as $25 to $27 50 for treating a ton of ore. The Stewart Company, however, seems to get the best of the struggle, though it apparently returns less to miners. The nominal charge for treatment is $35; but the company refuses all custom ore, and insists upon purchasing, according to sample assays.

The Airey furnace is not yet completed. It is understood that the proprietors of the Stetefeldt patents consider it an infringement, and that litigation will result from the attempt to run it. A feature of the Airey furnace not possessed by the Stetefeldt is a peculiar lining of the shaft, composed of cast-iron plates, which can be adjusted at will, so as to give a zigzag, instead of a straight shaft. It is useless to speculate upon the value of this feature, or the validity of the whole invention, in advance of actual trial. I sincerely regret that the Stetefeldt furnace was not, by some amicable arrangement, introduced into Clear Creek County. One such furnace would economically chloridize all the ores produced in the county, and a great saving to the mining industry would be the result. Summit County offers, perhaps, a still better field for it.

A striking commentary upon the common statement that high prices of reduction are the reason of the limited production of ore is furnished by the fact that the enormous reductions in price at the principal works of Georgetown did not effect a corresponding increase in the supply of ores. Professor Hill, at Black Hawk, has had a similar experience with gold ores. The fact is, that the production of ore is limited by the condition of the mines, and cannot be doubled at a given signal. No doubt a whole year of low prices will have a stimulating effect, but a permanent increase in production must be effected by systematic opening of stoping-ground; there is absolutely no other way, and until the mines of Clear Creek County can show large actual reserves, all talk of sudden increase in this respect is vain. A few mines are putting themselves in this condition. The list will be increased, I believe, this year, and the mines on that list will furnish the greater part of the ore treated. The small lots brought in for treatment by mere prospectors, when prices are favorable, form a precarious and comparatively insignificant supply. Of course, new veins may be discovered and rich pockets quickly extracted, or even large deposits, like those of the Caribou, in Boulder County, may be rapidly developed; but this cannot be counted upon, especially in a region so well prospected already as the neighborhood of Georgetown. There is no lack of good mines here, but there is great lack of well-opened, steadily-producing mines. It is but fair to repeat that the last year shows solid progress in this respect, and that there is still greater promise for this year.

H. Ex. 10-21

A noteworthy peculiarity of the operations of the year in Clear Creek County, as in some outlying districts, has been the so-called "tunnel fever." Innumerable sites for tunnel-mouths have been located along the cañons above and below Georgetown; many companies have been organized, and much money has been wasted in attempts to develop, by means of cross-tunnels, the "wealth" of this, that, or the other mountain. Even where such undertakings are commenced in earnest, as many of these were, they are extremely hazardous, and, as a general rule, to be condemned, for the following reasons:

1. A cross-tunnel is likely to be the most expensive of all methods of prospecting. It is run in dead rock, generally hard and costly to excavate, and it cannot furnish ore during its progress to help bear the cost. It is uncertain how much time and money will be required to complete' it, and if not completed it is worthless. As for the chance of expos ing numerous parallel lodes by running at right angles to the course of a lode system, it can only be said that experience shows few instances of very valuable parallel veins very close together; and it is far better to wait until such a state of things is proved than to run tunnels upon the expectation of it.

2. If a tunnel should cut a lode, it would still be necessary to drift upon it before its value could be ascertained; and if it were thus found to contain ore in working quantity, it would be necessary to open regu lar stopes for its economical extraction. But regular stopes cannot be opened without a shaft or winze. Either a shaft must be sunk from the surface, or a winze must be "raised" from below, in order to gain the requisite working face or breast. If the former, then the shaft would have been the better means of prospecting from the beginning. If the latter, then the difficulty and expeuse will be very great; and probably the shaft will have to be sunk from the surface after all, as the cheapest way to get air.

3. The uses of a cross-tunnel for prospecting and transportation of ores are properly incidental. The proper chief function of a tunnel is drainage. Where the cost of pumping is not so great as to call for them, expensive deep cross-tunnels should not be run. Ventilation is often greatly facilitated in this way, it is true, but only where the mines are deep and shafts are already open. Few American metal mines are so deep that ventilation cannot be effected through a proper arrangement of shafts. The cost of hoisting ore from such depths as most of our mines have attained is trifling compared with other mining ex penses; and few single mines could save the interest on the cost of a long tunnel by any reduction in this item. The cost of raising large quantities of water, on the other hand, is frequently very onerous; and in many cases a tunnel would be well worth its cost in this respect. But in such a case, the amount of water raised, the propertion of drainage costs to the value of the regular production, and the certainty of continued profitable operations are known elements of the problem; and the question of a tunnel becomes a commercial calculation, very different from a wild speculation.

4. It is evident, then, that deep cross-tunnels should be auxiliary, and not primary works. The history of mining in other countries gives us positive evidence on this point. All the great tunnels in Europe of which I have any knowledge were run principally for drainage, and always to connect with the workings of well-established productive mines. In this country, on the other hand, I cannot recall, out of numerous cross-tunnels, driven primarily for exploration and exploitation, a single instance in which the results have completely justified the meas

ure. These remarks do not apply to drift-tunnels, run upon the vein, nor to short cross-cuts to find or open a vein.

5. Thus far I have referred to those enterprises only which are undertaken in good faith for prospecting or developing lodes. It is quite likely that a group of mines upon a mountain will, at some time in the course of deeper operations, require and repay the construction of a deep tunnel; but one such tunnel is enough for a large area, and the location of a dozen or a hundred, side by side, is absurd. Moreover, the tunnel should be owned by the mines that need it, and paid for out of their profits; or else it should be constructed upon some agreement or charter binding them to pay for the accruing benefit.

6. The location of cross-tunnels to underrun well-known lodes, owned on the surface by other parties, with a view to extracting ore from them, until the owners can, by sinking upon the veins, establish their identity, is a piece of speculative piracy with which I have no sympathy, and the invariable failure of which, hitherto, seems to me but a just retribution. 7. The sale of "tunnel claims" at exorbitant prices, as if they were in themselves valuable property, is reprehensible. A tunnel claim may be a valuable auxiliary to the owners of the veins which can be drained by it. In and of itself it is the privilege of spending money to cut veins which may belong to other people. As far as blind lodes are concerned the tunnel claim does, indeed, give so many feet upon each vein discovered by the tunnel; but surface explorations would discover many more veins at the same cost than a tunnel will cut; because the surface prospector can go where he likes to look for outcrops, while the tunnel must hold a single course. It is almost as absurd to run a cross-tunnel after blind lodes as it would be to sink a shaft at haphazard in dead rock. The rights attached to a tunnel claim, unaccompanied by surface ownership of known lodes to be pierced, are extremely visionary. The only tunnel right which would be really valuable our laws do not give. I mean the right to exact a royalty from mines benefited by the tunnel. This has been granted by contracts and confirmed by legislation in the case of the Sutro Tunnel in Nevada, an enterprise which, I need hardly say, as it is connected with the largest, deepest, and most productive mines in the country, does not belong in the category I am now discussing. The tunnel royalty was, in Europe, for centuries the privilege of every one who should drive a tunnel not less than 30 feet deeper than any preceding one, so as to benefit an overlying mine.* I do not say it would be wise to make this provision generally applicable to our mines; but this I do say, that in the absence of some such tangible source of revenue, deep cross-tunnels, underrunning only undeveloped or unknown lodes, or lodes belonging to other owners, are gratuitous folly. 8. I do not mean to condemn individual enterprises in this particular district. Several tunnels, such as the Marshall and the Burleigh, have been prosecuted with great energy, skill, and perseverance, and have gone so far as to make the question of their continuance a very different one from the general question of the advisability of such works. Indeed, the best course may be to complete a few of the most advanced tunnels. What I regard as an evil is the multiplication of these enterprises, the diversion of labor from more productive methods of development, and the delusion and discouragement of capital by investments in wild tunneling schemes. The legitimate success of the Marshall or the Burleigh tunnel would be a well-deserved reward to the enterprise and tenacity of its projector; but it would not disprove the views I have

*See my report of 1869, page 196.

expressed on the general subject, nor counterbalance the mass of experience on the other side.

The Marshall tunnel is itself an illustration of some of my criticisms. It enters Leavenworth Mountain about two miles southwest of Georgetown, 930 feet above the cañon bottom, or about 9,382 feet above sealevel. Since March, 1868, it has been run about 850 feet, and cut six welldefined veins. Most of these veins were cut in lean ground, so that they must be otherwise tested, by drifting, before their value can be known. The last vein cut, however, is reported to show a large body of good-looking ore, and it is said that the owners of the tunnel will be reimbursed by this discovery. But the discovery must have cost them a good many thousand dollars, since the cost of excavation alone, by contract, has been from $26 to $30 per foot; and not everybody may expect to be reimbursed in this lucky way. A Colorado paper considers this success a proof that fissure veins are continuous in depth. So they are; and the proof was not necessary.

I repeat that I would not disparage or discourage honest and energetic enterprises now in progress, however strongly I may disapprove of their general method. All rules have their exceptions, and the question of cross-tunnels is one for careful calculation in each case. I do earnestly protest, however, against the tunnel mania, which, I think, is doing great harm to the mining industry of this part of Colorado. It would be strange, indeed, if in a district so rich in valuable lodes so many miles of tunnels should not develop something now and then; but the losses are terribly in excess, and wisdom dictates caution. The same amount of capital and labor will, I am satisfied, in the majority of instances, accomplish more in mining by shafts or drifts upon the veins. It is necessary, also, to warn capitalists that tunnel sites are merely sites for tunnels, that they ought to be auxiliaries of other mining property, and that the value of such property offered for sale must depend wholly on the actual development of the lodes, and not at all on the hypothetical development of the tunnels.

I speak earnestly and at length upon this subject, because the press of Colorado, however desirous of placing facts only before the public, is naturally inclined to applaud all activity and every investment of capital. The over-development of reduction works, which is relatively harmful as being premature, and the over-multiplication of dead work in tunnels, which is largely a positive loss, are more or less stimulated by indiscriminate praise of everybody who seriously undertakes to do any thing. Where so many voices cry encouragement, it is well that one should speak warning.

BOULDER COUNTY.

I have no knowledge of any placer mining in this county. It has become, however, during the past year, the scene of a remarkable development of silver mining in the so-called Grand Island district. This district was discovered, I believe, in 1869, or even earlier; but it was not until June, 1870, that the extraordinary value of its principal lode, the Cariboo, caused it to become the object of special attention and public excitement. I am indebted for detailed accounts of the mines to several gentlemen, principally to Mr. D. C. Collier, of Central City, who visited the district in November at my request.

Grand Island district is some twenty miles north of Central City, and about the same distance west of Boulder City. It is reached from the former place by an excellent road. A correspondent of the New York

Tribune who made the trip gives the following picturesque description of the route:

Leaving Central City in the morning and going down to Black Hawk, we passed up a gulch two or three miles long, and reached the level of the mountain ranges. All the slopes and the mountain tops were once covered with a heavy growth of pine timber, but for several miles around they had been cut clean away for the smelting of ores in Black Hawk and Central. After five miles of travel we passed thousands of cords of wood by the roadside, which had been hauled from the mountain slopes on either hand, and we could see vast blocks taken out of the solid forest. Not many years can pass before all the timber within ten or fifteen miles of Central will be gone, and then ores must be taken to the coal at the foot of the mountains. The road was dry and smooth, and none of the hills were steeper than in ordinary country roads in the States. The broad track indicated the constant travel of the long teams which all day long crowd the way, hauling provisions and supplies to Cariboo and returning with silver ore. Our general elevation must have been about 8,000 feet, while ranges and peaks on the right and left were 1,000 feet higher. We passed a great many cabins belonging to wood-choppers, and in coves, or upland valleys, there were ranches cr farm-houses and fields, of more or less extent, where oats, barley, potatoes, and other vegetables had been grown. Further on there were fewer dwellings, but I was surprised to find a fence made of poles along each side of the road, mile after mile, which it seems inclosed claims supposed to be of 160 acres, and which were occupied for pasturage. But these fences must have included a larger area, for high mountains from two to four miles distant made the only limit on that side.

We crossed a gulch known as Gold Dirt, where successful mining had been done, and then we came to the valley of the North Boulder, which presented a scene almost like a New England village, for there were several good residences, a large saw-mill, and several extensive stamp-mills, with lofty chimney-stacks, while the clear and rapid stream runs through a valley as beautiful as can anywhere be seen. Here heavy crops

of barley, oats, timothy, potatoes, and all kinds of vegetables were grown this season, and the proprietor, Mr. Rollins, declared that he should raise wheat next year, for he was certain that it could be grown with success. The elevation must be 2,000 feet higher than Mount Washington. He took me into his barn, which would do credit to the best farmer in New York, and it was crowded with hay and oats. He had poultry in large flocks, and fat hogs. Seeing that his work-oxen were sleek and fat, I remarked that they showed evidence of having had grain. He said that, so far from baving grain, they had not even had hay, and that they got all their living on the wild mountain grass. His hay is sold at the barn for $30 a ton, to be taken to Central. He showed me some timothy hay grown by irrigation; the stalks were over four feet long. As a general thing, irrigation is not required in the mountains, there being rain-fall enough for small grains and vegetables; still, where practicable, water is used, particularly for grass.

Going out of this valley we came among the mountains again, and yet the line of the road was so skillfully laid that we traveled as easily and rapidly as if we were going through some old settlement in Massachusetts; and the old granite rocks, and the mossy peaks, and the green mountain slopes seemed almost the same as along the Atlantic shore beyond old Salem. Making a turn around a mountain, we saw full before us the vast plains, smooth and gray like the ocean itself, and stretching without a break six hundred and fifty miles to the Missouri River.

Although it was twenty miles down to the foot-hills, the distance did not seem more than five or six, nor did it seem as if there was a descent of 3,000 feet, nor that in a direct line between them there were mountains so steep and inaccessible they had never been trod by human foot. Nothing is more remarkable than the excellent roads which have been made wherever mines have been worked, and they show an enterprise and a bold outlay of capital which is scarcely equaled in any other part of the country. By a road projected to Boulder City, eighteen miles from Cariboo, Grand Island district will be brought nearer to the plains than Central City.

The town of Cariboo is situated in a deep gulch, less than a quarter of a mile wide and half a mile long, with high mountains on three sides. The altitude of the gulch itself, however, must be at least 9,000 feet, as it is but a few hundred feet below the timber line, which in this part of the mountains is more than 10,000 feet above the sea. The gulch was formerly filled with a dense growth of mountain pine. Cariboo had, in November last, two main streets, one above the other; several steep cross streets; about thirty houses, including a hotel; several boardinghouses, stores, stables, and mining companies' offices, and a population

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