MINING 



3822 



MINING 



glancing into these black holes, may occa- 

 sionally catch the gleam of a miner's lamp 

 dancing far down like a will-o'-the-wisp. 



When a shaft has been driven down to tap 

 the bed, galleries are driven in all directions, 

 following the seam. There are main tunnels 

 and numerous branching tunnels, leading to the 

 spot where the miners are at work. Certain 

 great mountains in the West are simply honey- 

 combed with such workings. Unless the mines 

 are lighted by electricity, the men work, half- 

 naked, in a world of blackness, except for the 

 little islands of light cast by the pit-lamps they 

 wear on their caps. Each man, so to speak, 

 carries his own sun about with him, and this 

 sun has to be carefully shielded with a gauze 

 covering so that it will not ignite the gas and 

 cause a shattering explosion. 



Coal Mining. Coal mines being the most 

 common, it is the work in coal mines that is 

 described here. The miner descends into the 

 pit by means of a cage lowered and raised on 

 a wire rope, wound upon a drum. He follows 

 the main tunnel, in which a track for the run- 

 ning of small trucks is laid, to the branching 

 gallery that is nearest his work. Once at the 

 working face, he sets about the day's work with 

 drill, pick and shovel. With the pick and 

 shovel, or with a modern machine, called an 

 underwriter, he undermines a ledge of coaL 

 Above he makes numerous small holes with 

 the drill and inserts charges of black powder 

 in the glistening black surface. The blast is 

 set off and the coal is shattered and falls to 

 the floor. The miner's task is then to sort it 

 and load it into small trucks, which are later 

 hauled to the" mouth of the pit, either by 

 mules or at the end of a cable such as is used 

 in pulling cable cars through the streets of a 

 city. In some mines, where the seam is shal- 

 low, blasting cannot be done to advantage, and 

 the coal has to be brought down by hand. 



Accidents/ One of the terrors often present 

 to the mind of the worker underground is the 

 fear that the roof will fall on him. In spite of 

 all the precautions that are now taken, such 

 accidents claim more victims than any other 

 sort. More than 1,000 miners lost their lives 

 from caving roofs in 1913, out of a total death- 

 list of 2,785. To prevent this, the crushing 

 weight of rock and soil above has to be firmly 

 supported, either by stout pillars of coal left 

 standing here and there, or by timbers anchored 

 against ceiling and floor. These props, or 

 struts, are left standing in the active workings, 

 but when parts pf a mine are abandoned, it is 



usually thought best to remove the timbers 

 and allow the roof to cave in. 



Another danger which menaces the under- 

 ground worker is that of gas. Coal gives off a 

 gas that is easily ignited and gives rise to ter- 

 rific explosions (see FIRE DAMP). In order to 

 free mines from such impure air, rotary fans 



Pennsylvania 



Illinois 



West .Virginia 



Michigan 



Ohio 



California 



Minnesota 



Colorado 



Missouri 



Alabama 



Indiana 



Kansas 



Iowa 



New York 



Kentucky 



Tennessee 



Texas 



Washington 



Virginia 



Florida 



Idaho 



Wisconsin 



New Jersey 



Vermont 



Louisiana, 



South Dakota 



Maryland 



40 80 120 160 200 



280 320 



VALUE OF MINING PRODUCTS 



BY STATES 



CENSUS OF 1910 



Expressed in mil lions of dollars 



are employed. They are placed 

 near the shaft and are operated 

 by machinery. They either 

 drive fresh air into the workings 

 or exhaust the foul air through 

 pipes running to all parts of 

 the mine. 



The reader who imagines 

 himself in an underground city 

 with an orderly arrangement of streets and 

 alleys a wide main street with a number of 

 narrower streets and still narrower alleys all 

 leading to it will have a fair idea of the 

 average coal mine. The traffic conditions in 

 the mine, however, are sometimes better than 

 those of even large cities. Tracks are laid 

 on all the chief avenues, as well as in many 

 of the alleys, and issue ultimately upon the 

 main street. Down these tracks the coal is 

 hauled in trucks, which are linked together so 

 as to form a train on the main track. 



The trucks are hoisted up the shaft to a lofty 

 wooden structure called the tipple, where the 

 coal is weighed, sorted by being passed through 

 screens of varying size and dumped into coal 

 cars underneath. 



Importance of Industry. In the mines and 

 quarries of the United States over a million 

 workers gain their livelihood. The capital 

 invested was, according to the latest Federal 

 census, $3,380,525,841, and the value of the 

 product, $1,238,410,322. The most extensive 

 operations 'are conducted in the Middle Atlan- 

 tic states, where the industry amounts to almost 

 thirty per cent of the whole. Pennsylvania is 

 the leading state in the Union, the second being 

 Illinois. The greatest value $401,577,477 

 was the product of the mines putting bitumi- 

 nous, or soft, coal on the market; the value of 



