22.
At every shaft used for lowering or raising of persons or material where a mechanical ventilator is installed, There shall be provided a property constructed . . . . . . . .

25.
Where two or more seams or sections are worked in a mine, the pillars in one seam or section shall be vertically above or below the pillars. The parting left between any two such seams or sections shall not be less than "A" meters in thickness at any place. A is given by

28.
In a gassy mine of 2nd & 3rd degree the average monthly output of which exceeds 'A' tonnes, the Manager shall be assisted by a Ventilation Officer. 'A' is given by,

29.
In any shaft, ladder or strong construction may be used as a means of ingress or egress of persons employed in a mine. What should be the maximum inclination of such ladder from the horizontal?