1060 LAWS OF MARYLAND. [CH. 437

(b) Where the practice is to seal abandoned workings,
the sealing shall be done in a substantial manner with in-
combustible material. In every sealed area, one or more
of the seals shall be fitted with a pipe and cap or valve to
permit the gases behind the seals to be sampled and also
to provide a means of determining any existing hydrostatic
pressure.

(c) In gassy mines air that has passed through or by
abandoned sections or that has been used to ventilate pillar
lines shall not be reused to ventilate live face workings.
Mines that cannot comply with this requirement may con-
tinue to operate as at present until future mine develop-
ment and ventilation can be changed to permit compliance
with this Section.

104D. Examinations for Gas and Dangerous Conditions
(a) Not less than two permissible flame safety lamps in
proper working condition shall be kept available at each
mine for the use of authorized persons. Only permissible
flame safety lamps, permissible methane detectors, or air
sampling and analysis shall be used for determining the
presence of methane in mine air.

(b) In gassy mines, mine officials whose regular duties
require them to inspect working places shall have in their
possession when underground, a permissible flame safety
lamp in safe working condition, for the detection of
methane and oxygen deficiency.

(c) Fire bosses shall make examinations of all mines
before other men are permitted to enter, and they shall
begin their examination in the first working place in their
assigned territory not more than 4 hours before the first
shift enters the mine; however, such examinations in multi-
ple-shift operations may be made by certified officials or
other competent persons designated by the mine foreman
within 4 hours of the entrance of the next or succeeding
shift, provided that in mines in which gas has not been
found, such examination need be made only before
the first shift enters the mine.

(d) The duties of the fire boss shall be to visit every
live working place in the mine; test with a permissible
flame safety lamp for methane, noxious gases, and oxygen
deficiency; examine seals and doors, test and inspect the
roof, face, and rib conditions on active roadways and travel-
ways, approaches to abandoned workings, examine access-
ible falls in active sections for explosive gas and other
hazards; be certain that the air is traveling in its regular