2796 ARTICLE 89.

1922, ch. 307, sec. 114.

115. Ample and well-constructed switches and other protective devices
shall be provided upon all circuits, and especially upon branch circuits,
which shall be protected against electrical leakage and extraneous damage,
and all switches so devised that accidental closing or interference by un-
authorized persons may be prevented or forestalled; and in all circuits
where the load may suddenly approach or exceed the safe capacity of the
circuit or apparatus, circuit interrupting devices shall be installed.

1922, ch. 307, sec. 115.

116. Electric current of high voltage may be transmitted underground
only when the circuit is carried inside metallic sheaths or armor, such
sheaths or armor to be permanently grounded; and such current may be
applied only to transformers or motors in which the high voltage windings
are a part of the stationary element thereof.

1922, ch. 307, sec. 116.

117. Explosives shall not be hauled or transported in the vicinity of
live electric apparatus or circuits unless such explosives are placed in an
insulated, covered box; nor placed upon an electric locomotive at any time;
nor temporarily placed nor stored near electric currents or equipment;
and when explosives are carried by hand, the utmost precautions shall be
taken to avoid contact with electric apparatus or circuits.

1922, ch. 307, sec. 117.

118. Especial care shall be exercised along haulage ways and in any
portion of a mine where persons or animals may come into contact with
electric apparatus or circuits, and in all trolley circuits and transmission
lines, under which persons or animals must pass properly to install and
protect the same.

1922, ch. 307, sec. 118.

119. Care shall be taken in installation and maintenance of telephone
and signal lines to avoid and prevent grounds and crosses with circuits
of higher potential, and to protect persons using such lines from injury.

1922, ch. 307, sec. 119.

120. Systematic, periodic examinations and reports of the condition of
all wiring and electrical equipment and apparatus shall be required by
regulation of the Bureau, to be made by the operator, in all such mines.

CHAPTER XVII—Materials, Facilities and Supplies.
1922, ch. 307, sec. 120.

121. The operator shall provide and deliver at the working faces or
as near thereto as they can be conveyed in mine cars, a sufficient supply
of props, cap-pieces and timbers, cut square at one end, and as nearly as
practicable of the proper size and length for the purpose intended. Every