of the coal owned or leased where the coal is adjacent to coal owned by a person, firm or corporation, other than the owner or lessee of such mine, and where the excavations of such mine cease or may be approached by another mine, at points not exceeding three hundred feet apart, and referenced to some permanent monument near the main opening of such mine, and shown on the map and plainly marked bench mark, with the elevation of same. (Sec. 904, 917, 936, 937; Penalty, Sec. 976.) Sec. 936. [=Addition to map, and certificate of engineer and mine-foreman.=] The owner, lessee or agent of a mine shall cause to be made, a map or an addition to the next previous map thereof, annually, and semi-annually if so directed in writing by the chief inspector of mines, showing the excavations and the information required by the preceding section, to date of survey. The map, or maps, required by this and the preceding section, and any addition thereto, shall have the certificate of the engineer making same, and of the mine-foreman in charge of the mine at the time of the survey, acknowledged before, a notary public or justice of the peace, thereon in the following form: I, the undersigned, hereby certify that this map is correct, and shows all the information required by section nine hundred and thirty-five of the General Code, and covers the period ending .............................................. ............................. Engineer. Acknowledged before me a ...................... this .............. day of ...................................... ............................. I, the undersigned, hereby certify that I am a mine-foreman at the mine represented by this map, and to the best of my knowledge and belief the same correctly represents the excavations of the mine for the period ending ............................................................ ............................. Mine-Foreman. Acknowledged before me a ....................... this ................ day of .................................... ............................. (Sec. 904, 917, 937; Penalty, Sec. 976.)