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THE INSIDE OF A COAL MINE.

The term colliery includes the coal mine, with its buildings and appurtenances; the mine proper. is underground. The entrance to it is by a drift, a slope, or a shaft. "Stripping," which is quarrying, and not mining at all, is only possible where there is an outcrop of a thick bed of coal. The strippings are in the Lehigh and Schuylkill regions, where the coal is in the mountain tops. A drift is a horizontal tunnel in the face of an outcrop. It is the cheapest and was the earliest method of opening a mine, but the drifts have long since been worked out. A slope is a tunnel which follows down the dip of a coal bed from the surface. It is largely used in the Lehigh and Schuylkill regions, where the pitch of the beds is steep and outcrops frequent. In the Wyoming region the upper beds were formerly mined by drift and by slope; but these have been pretty generally exhausted, and access to the deep-lying beds is only possible by shaft. A shaft is a well-like excavation, opened vertically from the surface to the bed of coal which it is

desired to work. Its width is the length of a mine car, from 9 to 10 feet, and its length is governed by the number of compartments and area of airway needed. A shaft 10 feet wide

and 24 feet long is common, while some are 13 feet wide and 53 feet in length. Its mouth, as far as the soil extends, is lined with cribbing or masonry, below which the rock forms its walls. Its purpose is to hoist coal, to let the workmen up and down, and to pump and ventilate the mine. Over or near its mouth is built the hoisting and pumping apparatus, and it is divided by timbering into carriage-ways, pumpways, and airways. A shaft is usually located so that its foot shall be in the bottom of a synclinal valley, in order that as the mine is opened up the slope it will drain itself into a sump, and the coal will be sent down the grade to the shaft. The lowest place in a mine is the sump,-usually near the foot of the shaft, from which the water is pumped to the surface by powerful engines. From the foot of the shaft a tunnel called a "gangway" is opened at the right and left in the coal bed along the bottom of the synclinal valley, and parallel with this and above it runs another tunnel called an "airway." These are connected by short tunnels called "cross headings." The gangway is the highway of the mine; it is permanent, and is heavily timbered on the sides and roof; in it are the mine car tracks, single or double, over which the coal is hauled to the shaft; it is the traveling way through which the men reach their working places, and it is also a part of the ventilation system.

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The mining of coal is by the pillar and breast" system. When the gangway and airway have been driven two or three hundred feet chambers are opened at right angles to the airway, these are called breasts." A narrow tunnel, just wide enough to admit a mine-car track, is driven about fifteen feet, beyond which the breast is opened to its full width of from twenty-four to thirty-six feet, depending upon the safety of the roof. The inner end, which continually advances as the coal is taken out, is called the "working face," or simply the "face;" the side is called the rib." Several breasts are worked together, and at intervals are connected by openings called "cross headings." The walls between the breasts are thus cut into "pillars,' whose thickness depends upon the roof. dangerous mine the pillars are as thick as the width of the breast, that is, only 50 per cent. of the coal is taken out. Up the breast, as soon as it is opened sufficiently, is laid a track called buggy road," upon which runs a small minecar, or buggy." The track follows the development of the breast, and when that is worked out

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it is taken up. The process of mining is simple, and the tools are of the rudest. They are pick and shovel, bar, hand and machine drills, the latter an auger, turned by a crank,-and powder and squibs. The coal is loosened or "cut" from the face by blasting; the pick is only used to knock down loosened pieces from the roof and sides, to break up the largest pieces, and to separate the slate from the coal. The general plan

of a mine is that of a vast hall with pillars of coal, and roof and floor of the black slate which lies next to the coal; but its floor is seldom level, and the gangways are far from straight. The breasts may pitch so much that the coal is slid down to the gangway in chutes, instead of being hauled over buggy roads. We have seen that a mine is usually worked up the side of an anticlinal, as the surface of a hillside, while preserving in the main a uniform slope, yet drops into ravines and rises into ridges, so the coal beds bend and wind, and their course is followed by the gangways and the accompanying breasts. The distance that a breast can be worked depends on the vein of coal it follows. It may run to a boundary line; to an outcrop; to an anticlinal, when the bed begins to pitch down and the breasts to fill with water; it may thin out until the rock-roof and rock-floor come together; or it may strike a fault," which is such a disturbance of the strata that the coal bed is altogether lost.

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The mine described is the simplest form, in which only one bed is worked; several beds are often worked at one time, with entrance at different levels to a common shaft, or they may be connected by slopes and shafts within the mine. The coal region is a vast network of mines, so connected with each other that one may travel many miles underground; and lying above. each other, like the floors of a Brobdingnagian apartment house.

The last thing done is to "rob the pillars." This, notwithstanding its sinister sound, is a legitimate process. While a mine is being worked as much coal is taken out as is considered safe, leaving the pillars, sup

plemented by props, to support the roof.

When a mine, or a portion of one, is worked out, the miners are sent in to take yet more coal from the pillars, that is, to pare them to the last limit of safety. This work is begun at the farther end, and progresses toward the shaft.

THE VENTILATION OF MINES.

The modern system of mine ventilation is perfect; and while simple in method, it is extremely complicated in its ramifications. The air is exhausted at the air-shaft by a fan, and fresh air rushes down the main shaft to take its place. The law requires that not less than two hundred cubic feet per minute be furnished to each person in a mine. The fan, -which is a huge wheel without a rim, and with broad blades like those of a side-wheel steamboat, -revolves day and night. During a strike, when everything else comes to a standstill, two things do not cease to move, the fan and the pumps, for the stoppage of either would work irreparable injury. plan of ventilation.) As the air is drawn out at B, and fresh air rushes in through the gangway, its simplest course would be through the crossheading A into the airway, as indicated by the To prevent this partitions are built at

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GROUND PLAN OF MINE-SHOWING BREASTS, GANGWAY, AIRWAY, BUGGY ROADS, ETC.

A and C, compelling it to go to the end of the gangway and enter the airway at F. As long as the breasts

1, 2, and 3 have been worked only a short distance, the strong current of air rushing past their entrance ventilates them sufficiently, especially as the miners are in the habit of "brushing" out the powder smoke and gas by swinging their coats. over their heads; but as they advance, and new crossheadings are opened at G and H, partitions are built at F and D to compel the air to pass through G and H. If a breast is very gase. ous, a brattice of boards or "brattice cloth" is built, to force the air to pass close to the face." The partitions are built of "gob," which consists of rock and dirt, the waste of the mine. When a partition is built

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across a traveling way it has a door, which is opened and closed by a boy. It is often necessary for one air current to cross another, when it is conducted in an air-tight box called an "airbridge." Each current of air is called a " 'split," and the law forbids more than seventy-five men working in one air-split.

MINE GASES.

In addition to the smoke of blasting powder and the exhalations of the men and mules which foul the air, there are several dangerous gases. "Fire damp" is a light, explosive gas, which sometimes burns with a quick flash; sometimes explodes with terrific force, blowing down walls. and doors, and destroying the elaborate ventilating system in a moment. It often occurs as a "blower" or "feeder," which is a jet issuing from a fissure in the coal; it is apt to be ignited by a miner's lamp, and is usually put out by a blow of his cap, although mines have been set on fire by a blower. After damp," "black damp," and choke damp,"-loose names for different compounds of carbonic acid gas,-and "white damp," which is carbonic oxide, are all noninflammable and non-explosive, but deadly to inhale.

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It is the duty of the "fire boss" to examine the mine every morning before the entrance of the men, to see that the air currents are travel

ing in the proper courses, and that there are no dangerous accumulations of gases. Dangerous places are barred across and the word "Fire" written over them..

MINING ACCIDENTS.

There are two classes of accidents, -those which damage the mine, and those which injure the workmen. The disasters to the mine are the great explosions and extended falls, which bury the workings in a mass of rock and coal, and render them difficult to reopen; for when the roof is destroyed by the breaking up of the rock strata, it is only possible to hold it up by timbering. Mines are flooded by an inrush of water from abandoned workings in upper beds, and, in the Wyoming Valley, they are often filled with quicksand and gravel from pot holes; but the most serious of all disasters is a fire. There is much woodwork within a mine, and when this is set on fire it ignites the coal. There two ways of extinguishing a fire, by sealing from the air, and by flooding with water. The former is a tedious and uncertain process, as the coal may smoulder for months and burst out afresh on the admission of air. To fill a large mine with water, pump it out, and repair the damage to gangways takes from ten months to a year and a half, and the expense incurred is enormous.

There are two classes of fatalities; the great

disasters, in which a large number of men lose their lives; and the minor accidents, which occur day after day, of which the public takes no notice, but whose aggregate number is far greater than the former. In the thirty-two years since the anthracite mine law was passed more than ten thousand persons have lost their lives in and about the mines; but there have been few great disasters, the men simply fell out one by one or two and three in a group; and if, as was frequently the case, the victim was a Slav, with no relatives in America, the boarding boss refused to receive his body, saying "Dead Hungarian no good," and the corpse was sent to a medical college for the dissecting table.

There lies before me a fat volume, of almost a thousand octavo pages, which might be called the Book of Accidents." It is the report of the Bureau of Mines of the State of Pennsylvania for the year 1900, and is made up of the reports of the inspectors of the eight anthracite and ten bituminous districts. The inspectors give de tailed reports of each accident, and say that in from 50 to 70 per cent. of the cases the victims lost their lives by their own carelessness. Last year in the anthracite mines there were 411 lives lost and 1,057 persons injured. This loss of life made 230 widows and 525 orphans.

Mine accidents are caused by the explosion or inhalation of gas, by blasting, by fall of roof, or by miscellaneous causes, such as being crushed between cars, falling down, shafts, and being kicked by mules. During last year half of the fatal accidents occurred in the "breasts" by the fall of rock or coal.

Here will arise a natural inquiry, — Why, since so much damage results from fire and explosion, are not safety lamps used instead of naked lamps? There is a wide misapprehension concerning a safety lamp. nating lamp, but a test lamp. Davy" is in every school

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It is not an illumi The principle of the book of physics. It is that a flame enclosed in wire gauze will not ignite the gas outside of the lamp; but the gas will burn within the gauze, thus disclosing its presence. The light furnished by it is dim; and if the flame is strong enough to heat the wire to a red heat, it will in turn ignite the gas outside, thus becoming an element of danger.

Electric lighting has been tried, and does well in mines free from gas; but in gaseous mines there is too much danger, as a mine is such a rude place that the wire is apt to be broken, letting loose the electric sparks.

MINE LAWS.

The body of mine law in the statute books of Pennsylvania may be said to be a monument to

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the Avondale victims. The Avondale disaster, which occurred in 1869, was the first of those accidents resulting in a large loss of life with which the country has unfortunately become familiar. The Avondale mine was, compared with the great operations of to-day, a small affair. It was ventilated by a furnace at the bottom of the shaft, the shaft itself, with a tall chimney stack at its mouth, forming the ventilating flue. Over the mouth of the shaft was the breaker, and the mine had no other opening. One morning the furnace draught ignited the timbers which separated the flue from the carriage way, the flames caught in a load of hay which was descending by the carriage, and leaped to the top, where they set fire to the breaker, which burned fiercely for several hours, the mass of ruins covering the top of the shaft. In the mine were one hundred and eight men. It was two days be fore the imprisoned miners could be reached, the first of the rescuing party falling dead as they plunged into the body of white damp" which filled the mine. When they were finally found, behind barriers which they had built in a vain attempt to keep out the gas, they were all dead,not by fire, nor yet by explosion, but by suffocation.

The mine laws provide that no breaker shall be built nearer than two hundred feet from the mouth of the shaft; that every mine shall have a second opening for the escape of the men in case anything happens to the main shaft, and that mines shall be ventilated by fan instead of the inadequate and dangerous furnace. In addition to these radical measures, there are laws regulating to a minute degree the entire management of the mines with reference to the health and safety of the workmen,-such as rules limiting the amount of powder which may be stored in a mine; the distance which a miner's lamp must be kept from the powder, and the kind of oil used in the lamps; rules regulating the working of the breaker, and all other machinery; requiring the operators to furnish props, to fit up wash-houses for the miners' use, to provide stretchers and ambulances, and to use all possible effort to take out entombed bodies. The enforcement of all the regulations is under the supervision of State inspectors.

The latest laws are those abolishing company stores, requiring the operators to pay the men every two weeks on demand, and requiring miners to have certificates. The last law was aimed at the immigrants from Austria and Poland.

THE OUTSIDE OF A COLLIERY.

The external works of a mine are but a fraction of the mine itself. A colliery externally is a hole in the ground, with an unimpressive building

over it containing the hoisting and pumping machinery, and near by the breaker, with its attendant culm pile. The breaker is a feature of the landscape,-its size, its uniform black color, softened to gray by distance; its peculiar shape, unlike any other building in the world, and the long hill of refuse called the culm pile, make it an object that challenges attention. A roar of machinery emanates from it; and a cloud of black dust, pouring from a multitude of broken windows, envelopes it and blackens everything in its neighborhood. Its shape follows architectural principles, in that it strictly conforms to its uses. The coal is hoisted to the top of the breaker tower, where it is crushed between powerful toothed rollers; after which it falls into screens graded from fine to coarse; thence it travels through chutes, where the slate is picked out by boys; and, finally, falls into pockets at the bottom of the breaker, and thence into cars ready for the trip to the seaboard.

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A breaker is often 100 or 150 feet high, has a capacity of from 1,200 to 1,500 tons daily, and costs from $90,000 to $125,000 to build. The culm pile, which is as high or higher, is composed of the dirt and coal too fine for use, and is shaped like a prolonged A tent. Upon the top is a track, on which runs a mine-car pulled by a mule, a small locomotive, or often running by gravity. The culm pile is originally a high trestle with a track upon its top. Through the trestle the culm is dropped until it is filled to the top and spreads out in a long slope on either side. The tracks are extended upon this hill until the culm covers many acres, sometimes so encroaching upon a mining village that houses must be removed to make way for it. The culm piles contain much coal which escaped the scrutiny of the slate pickers, as well as the fine sizes which passed through the screens. It is the

CULM PILE.

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A COAL BREAKER.

habit of the women and children to pick coal from those shining black slopes, and in time of.a strike the miners themselves seek the culm piles with bags and baskets. These hills are frequently on fire, and burn for years. At night a burning culm pile is a mass of blue, orange, and red embers, which forms a beautiful spectacle that may be seen for miles. It not infrequently occurs that tramps, seduced by the pleasant warmth of one of these smouldering hills, lie down to sleep upon the culm, and are suffocated by carbonic acid gas.

In the early days of mining, "chestnut " was the smallest marketable size of coal; everything smaller was dumped upon the culm pile. Now since what are called the "junior sizes, ""pea, "buckwheat," and even "rice" and "bird's-eye," are largely used, it has become the practice to work over the old culm piles by the "washeries," where the culm is screened and cleaned by water, so that large percentage of coal is obtained, although it is of inferior quality, some of it having been mined twenty or even thirty years ago, and having suffered from exposure to the air.

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Culm is also beginning to be used for flushing back into the mines, that is, it is mixed with water and poured into the mines, when it immediately fills the worked-out chambers. After it has become settled, and the water is pumped out, it forms a solid mass, which supports the roof, so that the pillars can be taken out.

MINE EMPLOYEES.

The employees in the 363 collieries of the anthracite coal region in the year 1900 numbered 143,826. This is according to the latest report of the Bureau of Mines. The newspaper figures are somewhat in excess.

A breast is generally worked by four men,

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