Sec. 937. [=Owner, lessee or agent shall file map of abandoned mine with county recorder and chief inspector of mines.=] The owner, lessee or agent of a mine, before the pillars are drawn previous to the abandonment of a mine, or any part thereof, shall cause to be made a correct map of such mine, or part thereof, showing its area and workings to the day of the abandonment; the pillars drawn previous to abandonment; and file such map within ninety days after the abandonment of such mine, in the office of the Recorder of the county where such mine is located, and with the chief inspector of mines at his office. Such map shall have attached thereto the usual certificate of the mining engineer making it, and the mine-foreman in charge of the underground workings of the mine, and such owner, lessee or agent shall pay to the Recorder for filing such map, a fee of fifty cents. (Sec. 921.) [=Copy of map to be filed with chief inspector.=] The owner, lessee or agent of a mine shall keep at the office thereof, open to the inspection of the chief inspector of mines, and the district inspector of mines, a copy of the latest map of such mine, with any addition thereto, and shall furnish a copy thereto to the chief inspector of mines at his office. (Sec. 904, 917, 935, 936; Penalty, Sec. 976.) =Precaution when approaching abandoned mine.= Sec. 938. Whenever any working place of a mine approaches within one hundred feet of the abandoned workings of another mine, as indicated by an accurate survey, or while driving any working place within a distance of one hundred feet thereof, and such abandoned, mine cannot be explored, or when same contains fire-damp, or water which may inundate such working place, the mine-foreman shall not permit such working place to be advanced until a drill hole has been extended not less than twelve feet in the center of such working place, and a flank hole not less than twelve feet extended on each rib, starting at the working place after taking out each cut or crossing. Whenever the limits of the workings of an abandoned mine are not known by actual survey, the above rule shall apply whenever any working place approaches within one hundred and fifty feet of the supposed limits of such abandoned mine. In addition to the precautions provided for in this act when approaching or working parallel with such an abandoned mine, the owner, lessee or agent shall, upon the demand of the chief inspector or district inspector of mines, provide competent shot firers to do the shot firing in all the working places advancing or running parallel with such abandoned mine; the shot firing to be done when all other workmen are out of the mine. The chief inspector or district inspector of mines shall order shot firers at any mine when in their judgment the safety of property or employes require same. (103 O.L. 500.)