The Mine Inspector is hereby authorized, empowered, and directed to thoroughly inspect all underground excavations in all said mines as often as he may deem proper, from and after the passage and approval of this act, and ascertain the condition of such underground excavations, and, if after such examination, the Inspector shall find in any such mine or mines that the health of the employees is impaired by reason of there not being sufficient circulation of air or ventilation for such employees, it shall be the duty of such Inspector to immediately notify the operator of such mine or mines, in writing, specifying the underground excavations so found to be unhealthful, and direct such operator of such mine to, within fifteen (15) days after receiving such written notice, commence to drill a sufficient number of holes to such underground excavation, or to sink a shaft to connect with such underground excavation, or to make drift connection with a contiguous mine, as may furnish a sufficient ventilation for such mine or mines and to prosecute the work of correcting such defect in ventilation, with all due diligence until completed. And the Inspector shall have the power where and when the condition as aforesaid is such as to be injurious to the health of said employees, if he deems it for the best interest of the employees engaged in working in such underground excavations, so affected by such notice, to require all work and operations in such mine or mines to cease until such defect in ventilation shall have been corrected, or until further notified by such Inspector. During the process of shaft sinking fresh air shall be supplied from the surface. During the process of drifting or development for ventilation, forced ventilation shall be provided and sufficient ventilation shall be supplied in all dead ends. Where operations are carried on at a shaft not connected with any mine or shaft, ventilation shall be supplied from the surface by means of a fan through a conductor down the shaft or down one or more drill holes connected with the underground workings.

Laws 1929, c. 42, p. 47, § 6.