Several more or less conventional distinc tions are made as to the particular branch of work in which a mining engineer may special ize. He may devote himself to examining, valuing and reporting on mines, being engaged for such work by intending sellers or buyers; he may serve in the capacity of consulting engi neer for one or more mining companies; or in doing a general business he may be retained by his clients in an advisory capacity similar to that occupied by a counsellor-at-law, leaving to others the actual execution of the work or the carrying out of the policy determined Upon. On the other hand, a mining engineer who be comes identified with the management of the affairs of a particular company must be a suc cessful organizer and business man; he must possess the ability to make favorable contracts for work, the purchase of material and disposal of product, to control men, and not only to plan work but to know how it should be executed to attain the best economic results. He often combines with his purely professional functions the duties of superintendent or manager, and the smaller the property the greater usually is the variety of responsibility devolving upon the engineer. When in charge of a small or tem porarily non-paying mine, especially one situ ated in a remote region, the engineer may be compelled to serve simultaneously in the capaci ties of superintendent, foreman, assayer and bookkeeper. He must know enough of chemis try and of civil, mechanical and electrical engi neering to exercise intelligent control in mat ters relating to these branches, and he should have at least a general knowledge of mining law.
Formerly, the profession of mining engi neering was less complex and exacting in its requirements than at the present time. The great advances made during the past 50 years in scientific and technical lines have brought with them constantly increasing responsibilities. An inspection of the course of study prescribed in mining schools of good standing will show how largely the education of a student in min ing engineering lies in the direction of subjects not relating specifically to the art of mining itself. Manual labor has been more and more replaced by mechanical appliances, and the engineer must be alert in availing himself of the innovations which have been introduced in endless variety; the ever-widening applications of electricity and compressed air for the trans mission of power, the use of internal combus tion engines, the numerous improvements in machines and processes for the concentration and reduction of ores, the increase in knowl edge of the relations of geology to the deposi tion of ores; all these constitute new tools in the hands of the mining engineer, but they unite also in demanding a broader and more severe training. Up to 1870 applications of electricity and compressed air to mining were practically unknown; now they are employed in nearly all departments of mine work. Compressed air rock drills are used everywhere for both sur face and underground excavation of rock; electric and compressed air locomotives or rope haulage have superseded hand tramming and haulage by mules and horses, wherever the conditions are suitable and the quantity of material dealt with is sufficient to warrant the additional first cost of plant; the greatly increased depths at which mining is car ried on in many districts have made necessary the design and erection of enormously powerful and complicated hoisting engines; and finally, the successful and economical operation of such plants requires the maintenance of well equipped machine and other repair shops.
The question of hoisting large quantities of ore from great depths, that is, vertical depths of say more than 5,000 feet, is one of the most serious mechanical problems at present con fronting the mining engineer. Depths of approximately 5,000 feet have been already at tained in several mining districts, notably in the Lake Superior copper region and the Wit watersrand in South Africa, while in the important Butte, Mont., copper district, the silver mines of the Comstock Lode, Nevada, and the Bendigo gold fields of Victoria, Aus tralia, depths of 3,000 to 3,500 feet have been or are being reached. In a number of places where the present maximum depth of shaft does not exceed 3,000 feet, elaborate engines capable of hoisting from 5,000 feet or more have been installed. The prosecution of work at such depths involves the solution of rather intricate problems, among which are the proper construction of hoisting drums for winding the great lengths and weights of rope required, the design of reliable controlling apparatus for hoisting at speeds of 3,000, 4,000 or even 5,000 feet per minute, the means of raising and low ering with safety, speed and economy the hun dreds of men required in large and deep mines, and the difficulties involved in the varying weight of the rope itself, as it winds upon its drum, a weight which often greatly exceeds that of the ore raised at each hoisting opera tion. A high degree of mechanical skill and knowledge is demanded for the effective solu tion of these and other problems. Consult discussions on ((Hoisting from Great Depths,' which appeared during 1902 and 1903 in the (Transactions of the Institution of Mining and Metallurgy.) London, the South African Association of Engineers; and the Engineering and Mining Journal, New York.
In all branches of his work the mining en gineer of the present day finds himself com pelled to introduce every new method and appliance that promises some saving in the cost of production. This is the, result, not only of competition and of increase in wages but also of the reduction in market price of nearly all of the metals within the past four decades. In 1873 the price of silver was $1.30 per ounce; now (May 1919) it is $1.01; copper was then worth 30 cents per pound, now 15.3 cents; lead was then 6.5 cents per pound, now 4.7 cents, and other similar examples of the decline in value of the staple metals can be cited. Furthermore, as the more easily accessible mineral deposits are exhausted, the mining engineer is called on to practise his profession farther afield, often in regions remote from centres of population. Here he may be confronted with new problems arising from the lack of transport facilities, dis tance from source of supplies and materials, labor insufficient in quantity and poor in qual ity and adverse and unhealthful climatic con ditions.