arrows; the location and extent, so far as known or obtainable, of
the excavation of any other mine or mines within the limits of the
map; the boundary lines of the tracts of coal owned or leased within
the limits of the map; the elevation of the floor of the excavation,
above mean tide at Sandy Hook, at or near the boundary line or lines
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