2872                                                LAWS OF MARYLAND                         [Ch. 864

Any water or gas accumulation, or borehole from the
surface, may not be tapped until every worker, except
those engaged in this work, are out of the nine. The
work shall be executed only under the immediate
supervision of the mine foreman. Coal may not be mined
within 50 feet of any abandoned mine suspected to be
inundated with water, until the danger from the water has
been removed by driving a passageway to tap and drain it.
Further, any barrier pillar standing in the vicinity of
the abandoned mine must be in proportion of [one] 1 foot
of additional pillar thickness to each one and
one—quarter feet of watershed, if the district mine
inspector believes the thickness is necessary for the
safety of persons and property within the operating mine.

(b) If clay veins, spars, or faults are cut in
driving entries or other narrow work into solid coal, in
gassy mines, a borehole shall be kept not less than
[three] 3 feet in advance of the face or a like distance
in advance of any shot hole drilled for blasting.

7-456.

(a) Separate surface magazines shall be provided
for the storage of explosives, detonators, and cardox
heater elements. surface magazines for storing and
distributing high explosives in amounts exceeding 125
pounds shall be:

(1)     Reasonably bulletproof and constructed of
incombustible material or covered with fire-resistive
material. The roof of the magazine shall be located so
it is impossible to fire a bullet directly through the
roof from the ground. The roof need not be bulletproof,
but if it is possible to fire a bullet directly through
the roof, it shall be made bullet resistant by material
construction, or by a ceiling that forms a tray
containing not less than a [four] 4 inch thickness of
sand, or by some other method;

(2)     Provided with doors constructed of
three—eighths inch steel plate lined with a [two] 2 inch
thickness of wood, or the equivalent;

(3)   Provided with floors made of wood or other
nonsparking material which has no metal exposed inside
the magazine;

(4)   Provided with a suitable warning sign located
so a bullet passing directly through the face of a sign
will not strike the magazine;

(5)   Provided with a properly screened ventilator;