§ (1) General regulations under this Act shall provide for the classification of mines according to the amount of the inflamemable and noxious gases in the main return airway, and the amount of air passing into a mine shall be such amount, proportionate to the number of men and animals employed underground in the mine, as may be prescribed by the general regulations as respects mines of the class to which the mine belongs.
§ (2) The obligation imposed by this Section shall be in addition to, and not in substitution for, the obligation to provide an adequate amount of ventilation imposed by the last foregoing Section.
§ Amendment made: Leave out the words "be such amount, proportionate to the number of men and animals employed underground in the mine," and insert instead thereof the words "not be less than such amount."—[Mr. Masterman.]