DECEMBER, 1863.
District. Yield of Gold per Ton of Quartz.
Stormont (Isaac's Harbor) 2 oz. 10 dwt. 0 gr.
Wine Harbor 10 " 6 "
Sherbrooke 1 " 7 " 0 "
Tangier 14 " 12 "
Montague 5 " 9 " 8 "
Waverley 9 " 11 "
Oldham 15 " 12 "
Renfrew 1 " 2 " 0 "
Ovens[P] 18 " 9 "
The difference in yield between the districts is here very considerable, as it happens,—yet in the month of October the average yield at Oldham was 1 oz. 16 dwt, 20 gr., and at Renfrew 2 oz.; while for November it was at Stormont 3 oz. 2 dwt. 12 gr., at Tangier 1 oz. 10 dwt, at Waverley I oz. 3 dwt. 12 gr., and at Oldham 1 oz. 8 dwt. The maximum yield per ton was 50 oz. at Wine Harbor, 12 oz. at Sherbrooke, 11 oz. 12 dwt. at Oldham, and 5 oz. 15 dwt. at Stormont, for the same period.
"The average yield," says Professor Chace, "per ton of quartz, of the gold-fields of Nova Scotia will, it is believed, compare favorably with that of either Australia or California, while some of the maximum yields indicate ores of unsurpassed richness."
In regard to the best and most effectual methods of dressing and amalgamating these rich ores, it seems to be conceded that the modes hitherto in use in Nova Scotia have been very defective. Much larger returns of gold are to be expected from the introduction of the new processes, which scientific research is every day bringing to a greater degree of efficiency in Colorado and California. The promoters of the Nova-Scotia mining-enterprises, thanks to the skill and pains of their scientific advisers, are fully awake to the importance of this vital point. Pyrites—the mineral mixture so universally found with the gold of this region—is well known to escape, or rather to resist, the attraction of the mercury used in the amalgamating process, and it has hitherto been allowed to pass away with the "tailings", or refuse from the mills. When we state that it has been repeatedly shown to be from ten to twelve per cent. of the components of the ore, and that by test of the United-States Assay-Office its average yield is one hundred and twenty-eight dollars to the ton,—and by the careful experiments of Professor Silliman, at the Sheffield Laboratory in New Haven, it has yielded even as high as two hundred and seventy-six dollars and forty-nine cents to the ton,—the oversight and bad economy of its waste will be sufficiently apparent. It may safely be estimated, therefore, that the process of Dr. Keith, or some other equally simple and efficacious method of extracting this hitherto wasted portion of the precious metal from the accompanying sulphurets, will produce an amount quite equal, at least, to the previous minimum yield. The effect of such an increase in the returns will readily be appreciated by others besides the merely scientific reader.
In regard to the capacity of the various mines for the regular supply of quartz to the mills, it may be stated that ten tons daily is the average amount fixed upon, by the different experts, as a reasonable quantity to be expected from either of the well-conducted properties. Works of exploration and of "construction", such as will hereafter be pointed out, must, it is true, always precede those of extraction; but a very moderate quartz-mill will easily "dress" ten tons of quartz daily, or three thousand tons per annum, requiring the constant labor of thirty men, as shown by the large experience already gained throughout the Province. And this, says Professor Silliman, "is not a very formidable force for a profitable mine,"—particularly when we consider that the price of miners' labor in Nova Scotia rarely rises above the moderate sum of ninety cents per day.
If the quartz cost, to turn its product into gold bars, as high as twenty dollars a ton, there would be, says the same eminent authority, "a deduction of one-fourth [as expense] from the gross gold-product. The gold is about nine-hundred-and-sixty thousandths fine, and is worth, as already shown, over twenty dollars per ounce. But the cost of the quartz cannot be so much by one-half as that named above; and there is the additional value of gold from the pyrites and mispickel, as well as probably fifteen per cent, saving on the total amount of gold produced by improved methods of working."
The reason why so little alluvial gold is to be found throughout this district may be very simply and concisely stated. It will be observed, that the length of the gold-field lies mainly from east to west, while its width from north to south is over a much less distance, and therefore lies almost at right angles to the scouring and grinding action of the glacial period. No long Sacramento Valley, stretching away to the south and west of the quartzite upheavals, has here retained and preserved the spoils of those long ages of attrition and denudation. The alluvial gold has mostly been carried, by the action alluded to, into the sands and beneath the waves of the Atlantic Ocean; and it is only at the bottom of the numerous little lakes which dot the surface of the country, that the precious metal, in this, its most obvious and attractive form, has ever been found in any remunerative quantity in Nova Scotia.
This statement brings us naturally to the consideration of another of our opening positions, namely, that the gold of Nova Scotia is to be successfully sought only under the application of the most scientific and systematic methods of deep quartz-mining. That no pains nor expense has been spared by the present promoters of these important enterprises, in the very commencement of their mining-works, will perhaps be sufficiently evident from the fact that no step has been taken without the full advice and concurrence of the eminent mining authorities already cited. A summary of the methods now employed for developing the rich yield of these deposits may not be out of place in this connection.
The ill-considered system of allotting small individual claims, at first adopted by the Colonial Government, was founded, probably, on a want of exact knowledge of the peculiar nature of the gold-district, and the consequent expectation that the experiences of California and Australia, in panning and washing, were to be repeated here. This totally inapplicable system in a manner compelled the early single adventurers to abandon their claims, as soon as the surface-water began to accumulate in their little open pits or shallow levels, beyond the control of a single bucket, or other such primitive contrivance for bailing. Even the more active and industrious digger soon found his own difficulties to accumulate just in proportion to his own superior measure of activity; since, as soon as he carried his own excavation a foot or two deeper than his neighbor's, he found that it only gave him the privilege of draining for the whole of the less enterprising diggers, whose pits had not been sunk to the same level as his own. Thus the adventurers who should ordinarily have been the most successful were soon drowned out by the accumulated waters from the adjacent, and sometimes abandoned, claims. Nearly all of these early efforts at individual mining are now discontinued, and the claims, thus shown to be worthless in single hands, have been consolidated in the large companies, who alone possess the means to work them with unity and success.
The present methods of working the lodes, as now practised in Nova Scotia, proceed on a very different plan. Shafts are sunk at intervals of about three hundred feet on the course of the lodes which it is proposed to work,—as these are distinctly traced on the surface of the ground. When these shafts have been carried down to the depth of sixty feet,—or, in miners' language, ten fathoms,—horizontal drifts or levels are pushed out from them, below the ground, and in either direction, still keeping on the course of the lode. Whilst these subterranean levels are being thus extended, the shafts are again to be continued downwards, until the depth of twenty fathoms, or one hundred and twenty feet, has been attained. A second and lower set of levels are then pushed out beneath and parallel to the first named. At the depth of thirty fathoms, a third and still lower set of levels will extend beneath and parallel to the second. This work of sinking vertical shafts, and excavating horizontal levels to connect them, belongs to what is denominated the "construction of the mine", and it is only after this has been completed that the work of mining proper can be said to begin.