2780 ARTICLE 89.

tion and elevation of any body of water dammed within or held back in any
portion of such mine, giving as nearly as ascertainable, the true area of
such body of water.

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

1922, ch. 307, sec. 47.

48. Whenever the workings of any mine approach within three hun-
dred 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 immediately
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.

1922, ch. 307, sec. 48.

49. 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.

1922, ch. 307, sec. 49.

50. 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 provided for, all extensions of such mine
and mine workings, made during the intervening period, and all portions
of such mine and mine workings, discontinued and abandoned.

1922, ch. 307, sec. 50.

51. The operator shall furnish the district mine inspector for his offi-
cial 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 re-
production of the original map hereinbefore provided to be made; and
every six months thereafter an additional reproduction showing the. ex-
tensions thereof.

1922, ch. 307, sec. 51.

52. 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 abandoned 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 reproduc-
tions 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 duplicates in every particular and accurately show the lines