Report of the Bureau of Mines of the Department of Internal Affairs of ...

No. 10. MINING LAWS OF PENNSYLVANIA. Ixxvii
ARTICLE X.
Ventilation.
Section 1. The owner, operator or superintendent of every mine
shall provide and maintain a constant and adequate supply of pure
air for the same, as hereinafter provided.
Section 2. It shall not be lawful to use a furnace for the purpose
of ventilating any mine wherein explosive gases are generated.
Section 3. The minimum quantity of air thus produced, shall not
be less than two hundred (20U) cubic feet per minute for each and
every person employed in any mine, and as much more as the circumstances
may require.
Section 4. The ventilating currents shall be conducted and cir-
(Milated to and along the face of each and every working place
throughout the entire mine, in sufficient quantities to dilute, render
harmless and sweep away smoke and noxious or dangerous gases,
T(i such an extent that all working places and traveling roads shall
be in a safe and fit state to work and travel therein.
Section 5. All worked out or abandoned parts of a mine in operalion,
so far as practicable, shall be kept free of dangerous bodies of
gases or water, and if found impracticable to keep the entire mine
free from an accumulation of gases or water, the mine inspector
must be immediately notified.
Section 6. Every mine employing more than seventy-five (75) persons
must be divided into two or more districts.
Each district shall
be provided with a separate split of pure air and the ventilation
shall be so arranged, that not more than seventy-five persons shall
be employed at the same time in any one current or split of air.
The inlet and return air passages for any particular district must
be separated by a pillar of coal or stone, if the thickness and dip of
the vein will permit, except where it is necessary to cut through said
dividing pillar for the purposes of ventilation, traffic or drainage.
Section 7.
All air passages shall be of sufficient area to allow the
free passage of not less than two hundred (200) cubic feet of air per
minute for every person working therein; and in no case, in mines
generating explosive gases, shall the veloeity exceed four hundred
and fifty (450) lineal feet per minute, in any opening through which
the air currents pass, if gauze safety lamps are used, except in the
main inlet or outlet air ways.
Section 8.
All cross-cuts connecting the main inlet and outlet air
passages of every district, when it
becomes necessary to close them
permanently, shall be substantially closed with brick or other
suitable building material, laid in mortar or cement whenever practicable,
but in no case shall said air stoppings be constructed of
plank except for tempoiarv ])urposes.