The work of sizing up the quantity and the value of available ore is known as sampling. It is not well to limit the practice of sampling to the times only when a sale is contemplated. Reports based upon careful sampling should be issued frequently. Some companies employ men whose sole occupation is the daily sampling of every working face. The assay results obtained from the collected samples inform the superintendent just "how the stuff is holding up" throughout the mine and he governs his work accordingly. At longer intervals, the engineer should go into the work more thoroughly by not only taking very careful, scientific samples (not the usual "grab" samples taken by the daily sampler) but also by making careful memoranda of the physical appearances of the ore with its thickness and all geological data that will tend to throw light upon the permanency of each body. The engineer's monthly report will then be a substantial guide to the manager and the directors.
Managers, too, are expected to make periodical reports—monthly, quarterly, or annually—to the directors who, in turn, issue reports to the stockholders. The reports of managers and directors are not usually technical in their nature, although sometimes it is the practice of a manager to attach the engineer's report to his own for the perusal of such readers as may desire to dip into the technical affairs of the operations. Usually, the directors' reports are of a simple, financial nature, stating the conditions of affairs in plain business language to the persons whose cash has been invested in the enterprise.
It may happen that, for some reason, a special report is desired by the directors who may be contemplating some consolidation or other financial move and both the manager and the engineer will be required to furnish detailed statements concerning their respective branches. If a sale is planned, it may be that not only the company's engineer, but very probably another engineer engaged by the contemplative purchaser, will make examinations. They may work together or separately, as best suits them mutually, but it is upon the reports issued by them that the satisfactory price for the exchange of title is based.
[XIX
PRICES OF METALS.]
There is only one product of mines that has a constant market value, viz., gold. The precious metals, gold, silver, and platinum, are sold by the Troy ounce: the base metals are all handled and dealt with on avoirdupois weights. Copper, lead, zinc, tin, and nickel are quoted in cents per pound avoirdupois. Iron and manganese are curiously sold by mines to smelting companies on the ton of ore basis.
Since gold has been found in every known rock of every geologic age and is of world-wide distribution; since it possesses physical properties that long ago placed it at the head of the list of desirable metals; and further, since it does not occur in very condensed amounts, generally; this metal was selected as the standard of value by which the worth of every other commodity in the world is fixed. It must therefore be possessed of a fixed market value, and one never looks for quotations on pure gold. The price of pure gold is set at $20.6718. This very peculiar value is known as the "mint value," and is the price which the Government of the United States pays for all of its coinage gold. Among miners, as a rule, the price is thought of as $20 per ounce, and this is probably because this is more nearly the actual return the miner has been accustomed to obtain from companies who have bought and treated his ores. Most all the gold produced in the world is associated with other metals, such as silver, copper, or platinum, so that the bullion recovered in milling or smelting will usually contain the gold alloyed with such other metals and the gold is said to be not "fine," or pure. The fineness of gold in the metallic state is expressed in two ways. Jewelers have the carat system, while mints use the decimal system in expressing such degrees of purity. Pure gold is 24-carat fine. An alloy of 3 parts gold and 1 part copper would be considered as 18-carat gold. In the decimal system, pure gold is called 1,000 fine, and the various degrees of purity are then expressed in their true proportional amounts. Thus the same alloy as cited above would be called 750 fine gold.
Silver has a fluctuating market value although attempts have been made, at times, to establish its value at some fixed ratio to the value of gold. In fact, a reader may occasionally run across statistics of silver production in which it appears as though there were a fixed value for the metal, but this will be found to be due to the use of what is known as the "coinage value," which is $1.29198. This figure will be recognized as our old acquaintance, "16 to 1," i.e., this price for silver being one-sixteenth of the fixed price for gold. There is actually no such fixation, and prices for silver are established every business day of the year in the great metal markets of the world, London and New York.
Platinum has been increasing in market value during recent years and the quotations have ranged up so high that it is now more than twice as valuable as gold. The reasons for this high price are that the production of the metal is limited, whereas the uses for the metal have been increasing. The greatest production of this metal is in the Ural Mountains of Russia, and the output from this region is handled by a few concerns who virtually possess a monopoly. These companies are able to maintain the production practically constant and to cause the market price to fluctuate.
Tin is found in commercial amounts in but very few regions. There is but one mineral mined as an ore of tin, viz., cassiterite, the oxide, which is 78 per cent tin. Tin is found in both veins and placers and the great bulk of the metal is now being derived from the latter type of bodies in the Malay Peninsula and the Straits of the East Indies. Formerly, Cornwall produced the world's supply, from veins. Although the United States consumes 35 per cent to 40 per cent of the world's production, the country does not produce 1 per cent of this production. Since the main source of our tin is British territory, the markets are controlled by London, and quotations are issued daily from that center. Such quotations are given in units of English money per long ton (2240 pounds) of metal. However, prices are also quoted at New York, daily, in cents per pound, and there is a real difference in value between the two quotations to take care of freights and duty. For instance, on a certain date, quotations were £190 10s, and 42c. The average price during 1911 in New York was 42.281 cents.
The chief supply of nickel now comes from the Canadian districts of Cobalt and Sudbury, where this metal occurs accompanying rich silver deposits. The metal is sold by the pound avoirdupois and prices in January, 1912, ranged from 40c. to 50c.