ALBERT C. RITCHIE, GOVERNOR. 701

(d) The direction of the air currents in such mine, indi-
cated by arrows.

SEC. 47. Whenever the workings of any mine approach
within three hundred feet of the boundary line between such
mine and any adjoining mine, the operator thereof shall notify
the district mine inspector; who shall ascertain whether the
workings of such adjoining mine are, at their nearest point,
within three hundred feet of such boundary line, and imme-
diately inform the operators of both such mines; and such
operators shall have the approaching workings of such mines
surveyed and shown upon the maps of both mines; and for
the purpose of such mapping such inspector shall give written
permits to engineers of either or both operators to enter and
survey such adjoining workings of either mine.

SEC. 48. The original map hereinbefore provided to be
made, or a true copy thereof, shall be kept in the mine office
at the mine, for the use of the mine officials and the mine
inspectors, and for the inspection of any person working in
said mine whenever any such person shall reasonably so desire.

SEC. 49. Every six months the operator of every such mine
shall cause to be accurately shown on the map hereinbefore
required to be made, and upon the copies thereof herein pro-
vided for, all extensions of such mine and mine workings,
made during the intervening period, and all portions of such
mine and mine working's, discontinued and abandoned.

SEC. 50. The operator shall furnish the district mine in-
spector for his official use, to remain in the custody of the
Bureau and not without consent of such operator to be made
public, a good blue print or other exact reproduction of the
original map hereinbefore provided to be made; and every
six months thereafter au additional reproduction showing the
extensions thereof.

SEC. 51. Whenever a mine is worked out or abandoned,
the operator shall within sixty days thereafter extend the
map of such mine to clearly show all worked out or aband-
oned territory, and shall furnish the district mine inspector
with a good reproduction thereof, and a like copy to the
Bureau, to be kept as a public document. Upon all original
maps and reproductions thereof shall be endorsed a certificate
signed by the mining engineer or surveyor who prepared the
same, that said map and the reproduction thereof are dupli-