by vertical hoisting. Nevertheless some long and famous tunnels have been excavated in former years to drain important veins.
In the handling and transportation of ore underground, important problems are met in large works. It is accomplished in the levels by small cars, usually built of boiler plate to withstand the pounding that they receive, and these are pushed along by men on light tracks to the shaft. The operation is called tramming. If the shaft is vertical the ears are run directly on the cage, and hoisted to the surface, where they are dumped and returned. Large mines may have cages with two or even three decks, bringing thus two or three tram-cars at a trip. If the shaft is inclined, the tram-cars are dumped at the landing of the level into a car in the shaft that is open at the end instead of at the top. This is called a skip and its track is the skipway. The skip dumps automatically at the top of the shaft. In small mines an iron bucket is used instead of a skip or cage, but as soon as the output becomes at all large, buckets have to he abandoned. The transportation of the miners up and down deep shafts is also an important matter. They may, and as a rule do, ride on the skips, cages, or buckets used for the ore, special trips being made for them. Ladders, except for shallow depths, are no longer used in good practice unless in emergencies, as the climbing is too slow and exhausting.
In all mines one of the most dreaded things is fire. The forests of underground timber in many old workings make it a very dangerous accident, and even when in shaft houses at the entrances it often entails disastrous consequences on the men below. In coal mines there is the added danger of explosions and even of combustion of the coal. It is more and more customary, therefore, to locate boilers and engines in separate buildings from shaft houses, and to use every precaution against an outbreak.
In the organization of the force of miners the relations of employer and employed in mines are somewhat different from those of operations on the surface. The men are distributed as individuals and small parties in places more or less scattered and beyond regular superintendence. It is therefore often customary to let out work by contract rather than by day wages. A fair price is offered, based on experience, and usually estimated by the cubic yard or fathom of ore or rock excavated, and a party of miners organize and assume the contract. Active and energetic men do well under these circumstances, but as a rule the prices soon adjust themselves to about a fair average. The company furnishes supplies of explosives, drills, timber, etc., to the men at rates agreed upon. It also has a mine foreman, with subordinates to see that the work goes on satisfactorily, and at the end of each month the surveyor or engineer or superintendent measures up the work. In case the owners lack capital, or the vein is pockety and not adapted to systematic work in the large way, the ‘tribute’ system may be adopted. The parties of men then lease a certain block of ground and mine at their own expense and risk, paying to the owners a graded percentage of the value of the ore. If the men strike rich ore they realize high returns, but if it proves lean and low-grade they may actually lose. Old miners who know a mine thoroughly may often thus work to a great advantage. Owners of small capital sometimes get a new mine developed by leasing it to a party of practical miners for a percentage of the ore values for a limited time period. In this way the ore body is opened up without expense to the owners, but the leasers, who take the risks, naturally reap the lion's share of the profits. The relations of employers to men in remote settlements are also peculiarly close. The mining company of necessity furnishes houses, supplies, and all necessaries of life.
The production of the metals and useful minerals the world over has increased remarkably. Nowhere has the advance been more pronounced than in the United States, which is the foremost of mining nations, leading, in 1902, in the production of iron and steel, copper, gold, silver, mercury, coal, salt, and petroleum. Of the other more prominent metals and minerals, Spain is the chief producer of lead, Germany of zinc, and Russia of platinum.
For statistics and further information, consult the separate articles on the various metals.
Bibliography. The Transactions of the American Institute of Mining Engineers contain many papers relating to mining. Additional ones may also be found in the Engineering and Mining Journal (New York); The Mineral Industry (New York); Mines and Minerals (Scranton); the Engineering Magazine (New York); Mining and Scientific Press (San Francisco); Trautwine's Engineers' Pocket-Book (New York, 1902) contains many valuable data grouped for easy reference, and among other works may be mentioned H. M. Chance, “Coal-Mining,” Report AC., Pennsylvania Geological Survey; R. Peel, Coal-Mining (Philadelphia); E. H. Davies, Machinery for Metalliferous Mines (London); F. A. Abel, Mining Accidents and their Prevention (New York); A. Serlo, Leitfaden zur Bergbaukunde (Berlin); Barringer and Adams, The Law of Mines and Mining in the United States (Boston); The Coal and Metal Miners' Pocket-Book (Scranton, Pa., 1900); Foster, A Text-Book of Ore and Stone Mining (Philadelphia, 1900); Stretch, Prospecting, Locating, and Valuing Mines (New York, 1902); Wilson, Hydraulic and Placer Mining (2d ed., New York, 1903); Ihlseng, A Manual of Mining (3d ed., New York, 1901); Miller, Field Book of Practical Mineralogy (New York, 1901).
MINING CLAIM. The claim of a person to the exclusive right to work land in which he supposes he has discovered deposits of a precious metal; hence, the parcel of land supposed to contain the metallic deposits. The term is specifically used to designate the area of such metalliferous land which may be held under one location under the statutes of the United States, in which case the claim and location are identical if there is but one location; but if the miner acquires two or more locations the claim is usually used to designate the whole tract of land.
A mining claim is real estate, and descends to the heir, and is subject to taxation, execution, etc., as is any other real estate, and may also, in like manner, be protected by the action of ejectment. See Mines and Mining.
MINING ENGINEERS, American Institute of. A society founded in 1871, for the pro-
