of 1904, a Frenchman named La Rose, SLABS OF SILVER FROM TRETHEWEY MINE, radius of three or four miles of Cobalt lake was taken up, and many new mines were discovered. Before the end of the present season, and less than two years after the first discovery, upwards of fifty And yet this is not so strange after all, mines will be shipping ore from Cobalt. when we consider the peculiar character So far, some three million dollars' worth of the mines. The silver is found only of ore has been shipped. in narrow veins, generally not more than One of the peculiar things about the three or four inches wide, and showing Cobalt country is that before the final frequently at the surface only a narrow discovery, prospectors had been over and line of silver, perhaps not a quarter of over the ground, had camped time and an inch wide. Even in the richest mining again on the shores of Cobalt lake, but properties now in operation, some of the had never even suspected the existence best veins have been walked over day of the richest silver mines in America, after day by proprietors and workmen uncounted fortune within their grasp. alike, before being discovered. In the Slab back of hammer weighs 79 lbs., worth $491. Anal ysis-66.67 per cent silver, 2,15 cobalt, .41 nickel, 1.60 iron, 7.03 arsenic, 9.67 antimony, .22 sulphur, 6.72 calcium carbonate, 1.23 magnesium carbonate, 3.29 insoluble. ver come to appear here in this form? How deep do the veins run? Etc. The answer to such questions involves a good deal of technical explanation. In general, however, it may be pointed out that there are three classes of rock formation involved. At certain points an old rock formation called the Keewatin — or “greenstone," from its color is to be found. This Tent Hill, COBALT. greenstone was at a later Presbyterian church tent at right. stage covered with an other formation, called case of one of the mines, the story is told the Huronian. Through this Huronian, at that father and son had been out pros- a still later stage, at varicus points, there pecting for days and were at last tired surged up in molten form a conglomerate out and about to give it up, when the rock known as diabase. The diabase, in father lay down on the ground to rest, cooling, left cracks or fissures ; and it is and finding a stone under his head, went these cracks that are filled with the veins to remove it, when to his astonishment he of native silver. It is supposed that the found it to be solid silver. Another of silver was either strained out of the surthe mines—the Foster—was discovered rounding rock in its molten state or that as the result of trenching, i. e., removing it was deposited there by the heated the soil from the rock across a certain waters that surged up through these fisarea, and examining the exposed rock sures from below. surface for veins. This is an expensive Now, the diabase in which the silver method of prospecting, but in this in- is found is met with practically only in .stance it was worth the expense. the Huronian strata overlying the KeeBut if the veins are small and difficult watin rock. This Huronian rock has to discover on the surface, they are been worn down in many places by the nevertheless exceedingly rich, for in most cases they are practically solid silver, and the ore in some cases yields as much as $2,000 to $3,000 per ton. It is not an uncommon thing for nuggets of solid silver to be taken out weighing from 300 to 600 lbs. The ore itself is packed in sacks, shipped, and sold in three grades according to its richness. In connection with these views of silver, a number of interesting questions might be asked. How did the sil Part of TRETHEWEY MINE PROPERTY ON Hill OVERLOOKING COBALT. still be remarkable for its valuable deposits of smaltite—an arsenide of cobalt, nickel, and iron—from which cobalt is obtained. The uses to which cobalt is put have thus far been limited; but if Edison, who is operating a cobalt mine on the Montreal river, should succeed in extending its use, as seems probable, in the construction of electrical storage batteries, then the value of these mining properties will be immeasurably increased. But if the mines in the Cobalt district are interesting, Cobalt itself and the HUDSON BAY MINE. One of the newer plants just starting. neighboring towns are doubly so. Hither as by a magnet are drawn adventurous action of natural forces in the course of spirits from almost every quarter of the millions of years, and on the higher globe-Englishmen from the heart of London, Yankee speculators from “down ground the greenstone underlying it is East,” miners from California and Ausonce again exposed. It is supposed, tralia, German Jews, Syrians, Chinese, therefore, that the depth of the silver Italian navvies, Frenchmen from the veins depends on the depth of the Huron lumber camps, Canadian and American ian strata in which they occur; and it is estimated that in some places, in the tourists, broken-down merchants and rich millionaires, school teachers and natural depressions filling up old valleys, students, all striving directly or indithe Huronian formation is perhaps 500 rectly to gain some share of the newfeet deep, and the mines at such points found wealth. may be supposed to run to that depth The public square in Cobalt is the also. gathering place for most of this floating This whole question is, however, only population, and the scene presented from a matter of theory, and time alone will the steps of the banks or the theater on tell definitely whether these theories are te . either side on a summer evening is inter either side correct. It is worth noting, however, that esting in the extreme. The picturesque, the Huronian strata at other points farther north and south have not been found to contain silver in any quantity; and the only explanation that can be given at present, is that the small district some six or eight miles square in which Cobalt is situated was left undisturbed by the great forces and movements of nature that agitated the surrounding areas and prevented the silver deposits from being made. The process of mining the ore varies with different veins. Sometimes it is carried on by means of open trenching, no shafts being put down. But in most cases shafts are sunk either in the hillsides or perpendicularly, according to the position of the vein. The La Rose mine has already reached a depth of 250 feet, while the Trethewey mine has gone down only about 100 feet. Even if such rich veins of silver did SILVER VEIN AND DISCOVERY Post, TRETHEWEY MINE. not exist in this country, Cobalt would Slabs worth as high as $500 have been taken from this vein. |