MINING ECONOMY.
The economical mining of coal depends on the facility with which it can be taken from the miner to the top of the breaker.
FIRST.—The mine should be so planned and laid out as to enable the miner to work with security and in a pure atmosphere; which can be done only by a system of venti lation like that described in the preceding pages.
SECOND.—It is equally essential that the plans of working be so arranged that the miner can cut his coal with the greatest ease, and put it into the cars with the least amount of labor. The difference in this item ranges from 20 to 50 cents per ton in the anthracite mines,—depending on the size and character of the seam, and the manner in which it is mined.
THIRD.—To the operator and proprietor there is an interesting question concerning the amount of coal which can be obtained from an acre of ground. When the mines are opened, gangways and headings driven, railroads laid; in fact, all the expensive dead work done, and machinery erected,—to do which and keep the same in operation includes about one-third the expense of mining,—it is important that all the available coal opened should be obtained.
If the coal cost 50 cents per ton to mine and deliver on the top of the breaker, pro vided 30,000 tons per acre be mined from the Mammoth of 25 feet thickness, it will cost 70 cents per ton on the long run if only 20,000 tons are extracted. This may appear paradoxical; but a little figuring, or, better, some experience, will be con vincing. We consider the "boundary plan," as described in this work,—a modification of the English " board and wall" and " long-wall" modes,—the best and most economical that can be used.
FouaTn.—The facilities provided for the conveyance of the coal from the miner to the top of the breaker are important items. Good inside roads, easy grades, and room for the pass age of trains, are all items deserving attention. The size of the cars depends on the size and dip of the seam, and may be from one ton to four tons in capacity; from two to three, however, may be the most economical, since they must occasionally be handled by men.
At the bottom of the slope or shaft, arrangements should always be made for the easy and rapid transfer of the cars,—the empty one coming down, and the loaded one going up. The same arrangement should be made at the top of the slope or shaft, so that the cars shall move by their own gravity, not requiring manual labor to start them from their position.
FIFTH.—Elevation of the breaking, screening, and separating machinery is essential. An elevation of from 50 to 75 feet is generally required. A shute or bin above the rolls or breaker proper is desirable to hold the coal on coming from the mines, and to give the laborers opportunity to select the coal in the luinp, and pass the required kinds and sizes through the breaking-rolls. Screens should also be provided to separate certain portions of the coal. Steamboat and lump coal, of course, need not go through the breaker, unless a large amount of steamboat coal is required; neither should that por tion of the coal which is already small enough go through the breaker-rolls. By pro
viding for those sizes, much waste and some labor may be saved, and the crowding of hands will be avoided; while the slate and impurities may be separated from the coal in the rough, or before they are shattered and scattered by the breaking process. The separation of the dirt from the coal, and of the small coal from the large coal, also facilitates the selection of the rock, slate, and bone from the coal.
SIXTH.—The foregoing embrace the principal items of economy in mining, as far as the design and style of works are concerned ; but perhaps the most important item, after all, in the economy of mining, is efficiency of management. Energy and constant attention are required in all cases; but these qualities are second only to judgment and experience. We have often noticed the great difference in the cost of mining and preparing coal, under the same circumstances and conditions in seam and general availability, in two collieries, owing to the difference in management.
In one case we see the greatest activity and energy displayed, but, unfortunately, leaks that can only be seen by experienced eyes are making sad drainage on the profits. In another case we notice a calm, almost careless expression and action, but we see the greatest order and system in the operation, and no item that could be improved or expense that could be saved.
A large amount of the work done in the interior of the mines can be done with more economy by contract work than by day's work. Miners, like most business men, look sharper to their own interests than to other people's. They may do a fair day's work for one dollar and fifty cents, but they will do more if they can make three dollars per day by contract. Now, it happens that coal-miners will ask one dollar per wagon or car for cutting coal, if they can get it for asking, and they will often say that they cannot do it for less; but the experienced manager knows it can be cut for fifty cents, and he will not give more. A yard of gangway may be driven for five dollars, but the miner may want seven dollars and fifty cents, and may not accept less ; whereas some one else may take it and make good wages at five. Breasts may be driven by the yard under con tract,—say 20 yards wide,—but, if the miners are not watched, they will contract them to 15 yards; and thus, if the coal be 30 feet thick, 50 tons of coal will be lost to the proprietor, which may be worth to him 50 dollars, under the circumstances.* These are only a few out of hundreds of instances which might be named in which judgment and experience are of more importance than energy and action; but when all are combined in the management, we find the result in profits.