smaller number if the inspector deems necessary. In Indiana a separate current is required for each 50 persons, while in Washington it is required for each 75 persons unless the inspector finds that the system of splitting the air can not be adopted except at extraordinary expense. Pennsylvania (sec. 243) requires a separate current for each 65 persons, but the inspector may permit not over 100 to work in the same current. Tennessee requires the splitting of air for each 50 persons in case explosive gas is known to exist in the mine. Tennessee also prescribes the size of the intake and return air shafts.

Several States (Alabama, Indiana, Iowa, Maryland, Missouri, Montana, and Washington) especially provide that, if the mine inspector shall find men working without sufficient air, he shall order the operator to rectify the condition, and, in case of failure to do so, shall either himself order the men out of the mine or appeal for injunction from the courts to restrain the working of the mine. Similar powers are conferred upon the inspector incidentally in connection with other powers in many States. (See above, p. 238.)

Pennsylvania (sec. 270) permits condemnation of adjacent lands when necessary to secure proper ventilation or drainage for any mine.

Machinery and ventilating apparatus. To secure the required ventilation the laws usually provide that any satisfactory appliance, such as fans or furnaces, may or shall be used. In Washington, however, the use of a furnace for ventilating is prohibited. Tennessee and Indiana forbid the use of a furnace where breakers or other buildings stand directly over the top of the shaft; while in other States (Arkansas, Colorado, Indiana, Iowa, Missouri, and Montana) where furnaces are used the shaft must be lined with incombustible material to prevent danger of fire. Montana adds that furnaces must not emit smoke into any shaft or slope which is the only means of egress. (See also provisions as to ventilating shafts used as escapements, p. 246.)

Pennsylvania (sec. 244) requires ventilating fans to be kept in continuous operation, unless by permission of the inspector, specifying certain hours; in all cases fans shall be started two hours before beginning work.

In Pennsylvania (sec. 314) and Washington it is provided that, if ventilating machinery breaks down or ceases to operate, the workmen shall be withdrawn from the mine, and that where inflammable gas is believed to be present the mine shall be properly inspected with a safety lamp before they are allowed to reënter. In Pennsylvania the duties of fan engineers in such cases are especially regulated, as well as their general duties (sec. 334) and those of furnacemen (secs. 313, 335-337).

The Pennsylvania act (sec. 265) further declares that after its passage no principal ventilating fan shall be placed inside of a coal mine. wherein explosive gas has been detected or wherein the air is contami nated with coal dust. Stationary boilers must be placed more than 50 feet from the bottom of the upcast shaft. All ventilating fans must be provided with recording instruments for showing the number of revolutions and the effective ventilating pressure, and records of these shall be kept (sec. 376).

Fire boss-Measurement of currents. The laws of Alabama, California, Colorado, Illinois (secs. 16, 18), Indiana (sec. 7479), Kansas, Montana, New Mexico, North Carolina, Ohio, Pennsylvania (sec. 258), Tennessee, West Virginia, and Wyoming provide especially that each

coal mine must have a competent foreman, mine boss, or fire boss. Some States require a separate officer to act as fire boss. The boss shall keep a careful watch over the ventilating apparatus and air ways, shall examine working places to discover fire damp, and in most cases is required to measure the air current at least once a week, and to keep a record of the measurement, which shall be open to the inspector, and which in some States must be reported to him monthly. The Illinois and Pennsylvania laws are especially full as to the duties of fire bosses (see pp. 288, 303). (See also provisions as to foremen and bosses, p. 240.)

Doors. To secure the proper circulation of air, it is provided in Alabama, Colorado, Indiana, Illinois, Kansas, Missouri, Montana, Ohio, Pennsylvania, Tennessee, Washington, West Virginia, and Wyoming that all doors in the mine which regulate the current shall be so hung or adjusted that they will close themselves. The Kentucky law simply provides that proper doors shall be furnished. In Illinois, Indiana, Missouri, Montana, and Ohio the law requires that a boy or "trapper" shall be kept at the doors to see that they are properly closed, at least in the case of the larger mines, and a similar requirement exists in Pennsylvania unless approved self-acting doors are used. The Kansas laws prohibits employees or others from leaving doors open longer than while passing through, and requires that any person who tears down a brattice cloth must immediately notify the mine boss, and it must be promptly replaced. Tennessee declares that the main air door on any traveling road shall be double and an extra door shall be filed, to be closed only in the event of an accident to one of the others, and the sides and top of such doors shall be well built with stone and mortar where the inspector deems necessary. The Washington act provides that the main doors in a mine shall be so placed that whenever one door is open another which has the same effect on the current of air shall remain closed. Pennsylvania requires an extra emergency door on inclined planes or machine-haulage roads (sec. 246).

Break-throughs. In order that the ventilation may be sufficient and the currents of air reach to the working faces themselves, the statutes frequently provide that break-throughs or air ways shall be made from one drift to another at certain intervals, or that the working face shall not be driven more than a certain distance ahead of a current of air. Thus in Iowa, Kentucky, North Carolina, Ohio, and Washington no working place may be driven more than 60 feet in advance of a breakthrough, and all break-throughs except those last made near the working face shall be closed up to force the air forward. The distance between break-throughs in Pennsylvania is left to the discretion of the inspector, but must not be more than 35 yards nor less than 16 yards. The Indiana laws require break-throughs to be made at least every 75 feet and also provide for closing up all but the last one, while Wyoming requires break-throughs every 16 yards. Break-throughs in Kansas must not be more than 40 feet apart and must be at least 6 feet

'The Kansas act in full (Acts 1895, ch. 171):

SEC. 1. It shall be unlawful for any mine owner, agent, lessee or operator of any coal mine, or any other underground workings, where any kind of mineral is mined or excavated, in either shaft mine, slope mine or drift mine, by system of room and pillar, to mine or cause to be mined by any employee employed therein, in any of said mines, any minerals mined by bushel, ton, or other rates, to excavate coal or

wide and to the full height of the coal strata if not over 6 feet, in no case to have an area of less than 21 square feet. Unused breakthroughs must be properly closed. Alabama and Colorado leave it to the discretion of the mine inspector to require break-throughs at such intervals as he may deem necessary; while Illinois (sec. 16) requires mine managers to provide sufficient break-throughs and (sec. 19) to close them substantially with brick or similar material laid in cement. Special precautions against fire damp.—In most of the States legislating regarding ventilation it is provided that where fire damp or explosive gas is known to accumulate in a mine or a part of a mine, accumulations of standing gas in working places shall be prevented, and a competent person, usually the fire boss, shall examine the mine with a safety lamp every morning before the men are permitted to enter for work, while in most cases some method of recording the fact of such inspection is required: Alabama (secs. 23, 26), Arkansas, California, Colorado, Illinois, Indiana (examination before every shift), Kansas, Kentucky, Missouri, Montana, New Mexico, North Carolina, Ohio, Pennsylvania (before every shift, sec. 248), Tennessee, Washington, West Virginia (before every shift), and Wyoming (before every

other minerals, in an advance space of forty feet, unless break-throughs are made, ranging in distance as follows: Forty feet shall constitute the distance between breakthroughs, which shall be made through the pillar which divides either rooms, air courses, or entries, where any of said rooms, air courses or entries are in operation, and in no case shall the distance exceed the aforesaid distance, namely, forty feet, irrespective of thickness or distance of the pillar or pillars which divides such rooms, air courses or entries.

SEC. 2. Said break-throughs shall be at least six feet wide and the full height of coal strata, or other minerals mined which does not exceed six feet in height, and in no case shall the air courses have less than thirty-six feet of an area, where mines are operated on room and pillar system. And the compensation for making such break-throughs shall be regulated by or between the employer and employee; and any room, air course or entry, or any other working places where miners or others are employed, shall cease operation at the working faces until said break-throughs are perfected as herein specified, in section 1 of this act. And said break-throughs shall be filled with either slate, rock, or closed by brattice, to make the same airtight, as soon as the second or succeeding break-throughs are made. And in case any of such break-throughs are partly opened or torn down, by the concussion of shots, or blasts, or by premature explosion, or otherwise, the foreman or superintendent, or agent in each of any of the said mines, shall immediately cause any of such break-throughs to be properly closed and made air-tight, as soon as notified by an employee.

SEC. 3. Every mine owner, agent, lessee or operator of coal mines or underground workings of the character mentioned in section 1 of this act shall provide, and hereafter maintain for every such mine, ample means of ventilation, affording not less than 100 cubic feet of air in every such mine, per man per minute. Said volume of air shall be directed or circulated, where any person or persons may be working in any of said mines.

SEC. 4. The inspector of mines shall cause the volume of air to be increased when necessary to such an extent as will dilute, carry off, and render harmless, the noxious gases generated therein. And mines generating firedamp shall be kept free of standing gas, and every working place shall be carefully examined every morning, with a safety lamp by an examiner, or fire boss, before miners or other employees enter their respective working places. Said examiner or fire boss shall register the day of the month at the place of the workings, and also on top in a book which shall be kept in the weighmaster's office for such special purpose, and as proof of inspection, he shall daily record all places examined in said book, and in case of danger where firedamp may have accumulated during the absence of any person, or persons, employed therein, said examiner or fire boss, must notify the miners or those employed therein, or those who may have occasion to enter such places. And the hydrogen or firedamp, generated therein, must be diluted and rendered harmless, before any person or persons enter such working, or abandoned part of the mine with a naked light.

shift). In Maryland it is enacted that whenever noxious gases are known to exist in a mine it shall be the duty of the mine inspector, on information, to examine the mine and require the owner to close it or any part thereof, or properly ventilate it.

In Pennsylvania and West Virginia the law requires that mines generating fire damp shall be kept free from standing gases in the worked-out parts as far as possible, and that entrances to such parts shall be properly closed and a warning posted. In such mines, also, Colorado, Illinois, Montana, Kansas, Pennsylvania (sec. 368), and West Virginia provide that accumulations of fine dry coal dust must be prevented as far as possible, and when necessary must be watered down.

Colorado adds that where gob fires are known or suspected to exist a careful inspection shall be made daily. If an increase of temperature be found, prompt action shall be taken to put out the fire, but if it has reached such proportions that it can not be extinguished suitable stoppings shall be built, consisting of double walls of a concave shape, such as to completely isolate the fire from air. If combustion is still suspected, then steam and water, if practicable, shall be used to extinguish it.

Missouri, Montana, and Pennsylvania declare that no persons shall be employed where they are likely to come in contact with explosive gases, unless they are in charge of persons whom the foreman knows to have had experience sufficient to insure the safety of the miners.

Bore holes. In order to prevent excavations from breaking through unexpectedly into parts of mines or other places containing fire damp, it is provided that bore holes must be driven in advance of the excavations when approaching abandoned workings likely to contain fire damp or water. In Arkansas, Colorado, Illinois (sec. 25), Missouri, Tennessee, and Washington the law requires that these bore holes shall be driven at least 20 feet in advance of the face of the working place, and if necessary on the sides thereof. Colorado adds that these side bore holes shall not be more than 25 feet apart. In Alabama and Indiana workings approaching such accumulations of water or gas shall not exceed eight feet in width, and front and side bore holes must be made not less than three yards deep. The bore holes in Kansas, Pennsylvania, Washington, West Virginia, and Wyoming must be at least 12 feet in advance, and when necessary must be driven on the sides also. In Pennsylvania the side holes must be not over eight feet apart, and bore holes are also required in the cutting of clay veins, spars, or faults, in entries, or other narrow workings going into the solid coal.

Pennsylvania (sec. 374) and Wyoming declare that accumulations of gas or fire damp shall not be removed by brushing in any way. The Pennsylvania statute further provides that in case gas is ignited by blasting or otherwise the miner shall put it out immediately, if possible, and if unable to do so he shall immediately notify the mine

foreman.

Safety lamps.'-Alabama, Colorado, Illinois, North Carolina, Ohio, Pennsylvania, Tennessee, and Wyoming provide that all safety lamps

1Ala., Acts 1896-7, No. 486, sec. 13; Colo., An. St., sec. 3186; Ill., L. 1899, Apr. 18, sec. 29; Kan., G. S. 1897, ch. 149, sec. 44; N. C., L. 1897, ch. 251, sec. 6; Ohio, R. S., secs. 301, 306, as amended 1894, p. 160, Pa., Dig., Coal Mines, secs. 252, 253, 268, 363, 365; Tenn., L. 1881, ch. 170, sec. 9; W. Va., Code 1891, p. 991, sec. 10, Wyo., Acts 1890-1, ch. 81, sec. 6.

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used in coal mines shall be the property of the owner or operator of the mine and shall be in charge of the agent, mine foreman, fire boss, or other competent person. In Pennsylvania the law specially defines the cases in which safety lamps must be used. The use of electric currents in places where safety lamps are required is prohibited (sec. 251). Alabama and Pennsylvania declare that a sufficient number of safety lamps, not less than 25 per cent of the lamps used, shall be kept at each mine where gas has ever been generated. Illinois gives the mine inspector power to require the necessary number of lamps. Alabama, Illinois, North Carolina, and Pennsylvania declare that the person in charge of the safety lamps must properly care for them and deliver them locked and in safe condition to the men before each shift. In Alabama and Pennsylvania any person whose safety lamp is defective or injured must promptly report the fact to the mine foreman. In North Carolina no unauthorized person shall have in his possession a key for unlocking a safety lamp, and no matches are allowed in mines except under the direction of the mine foreman. Pennsylvania provides that no one except a person duly authorized by the mine foreman shall have in his possession a key to safety lamps, and that no one shall be intrusted with a lamp until he has given sufficient evidence to the mine foreman that he understands its proper use. The use of the common Davy safety lamp is prohibited, and the Clanny lamp may be used only if its gauze is thoroughly protected by a metallic shield.

Pennsylvania further declares1 that no explosive oil shall be taken into coal mines for lighting purposes except when used in approved safety lamps and that oil shall not be stored in mines in quantities exceeding five gallons. Places where cars are oiled or greased must be thoroughly cleaned to prevent accumulation of waste oil. In Indiana,* Missouri, Pennsylvania, and Ohio only a pure animal or pure cottonseed oil, or oils as free from smoke as these, shall be used for illuminating purposes. The Indiana, Missouri, and Ohio laws are detailed as to tests of oil. Kansas prohibits the use of any other oil than lard oil for lighting purposes.

1

3

1L. 1899, ch. 74.

4

2 L. 1899, ch. 144, sec. 1.

3 L. 1895, Apr. 9 (p. 225).

* Ohio, R. S.:

SEC. 306 (as amended by act passed March 29, 1892, Laws of Ohio, vol. 89, page 164, and by act passed April 19, 1894, Laws of Ohio, vol. 91, page 160). Only a pure animal or vegetable oil, or other oil as free from smoke as a pure animal or vegetable oil, and not the product or by-product of rosin, and which shall, on inspection, comply with the following test, shall be used for illuminating purposes in the mines of this State: All such oil must be tested at 60 degrees Fahrenheit. The specific gravity of the oil must not exceed 24 degrees Tagliabue. The test of the oil must be made in a glass jar one and five-tenths inches in diameter by seven inches in depth. If the oil to be tested is below 45 degrees Fahrenheit in temperature, it must be heated until it reaches about 80 degrees Fahrenheit; and should the oil be above 45 degrees and below 60 degrees Fahrenheit, it must be raised to a temperature of about 70 degrees Fahrenheit, when, after being well shaken, it should be allowed to cool gradually to a temperature of 60 degrees Fahrenheit, before finally being tested. In testing the gravity of the oil, the Tagliabue hydrometer must be, when possible, read from below, and the last line which appears under the surface of the oil shall be regarded as the true reading. In case the oil under test should be opaque or turbid, one-half of the capillary attraction shall be deemed and taken to be the true reading. Where the oil is tested under difficult circumstances, an allowance of onehalf degree may be made for possible error in parallax before condemning the oil for use in the mine. All oil sold to be used for illuminating purposes in the mines of this State, shall be contained in barrels or packages branded conspicuously with the name of the dealer, the specific gravity of the oil, and the date of shipment.