(_f_).--Lamps equipped with internal igniters will be placed in
explosive mixtures of air and gas in a quiet state and in a moving
current, and the effect of the igniter on the surrounding mixture will
be observed.

(_g_).--The oils (illuminants) used in the lamps will be tested as to
viscosity, gravity, flashing point, congealing point, and composition.

(_h_).--Safety-lamp globes will be tested by placing each globe in
position in the lamp and allowing the flame to impinge against the globe
for 3 min. after the lamp has been burning with a full flame for 10
min., to determine whether the globe will break.

(_i_).--Each safety-lamp globe will be mounted in a lighted lamp with
up-feed, and placed for 5 min. in an explosive mixture of air and gas
moving at the rate of 1,000 ft. per min., to determine whether the heat
will break the glass and, if it is broken, to note the character of the
fracture.

(_j_).--Safety-lamp globes will be broken by impact, by allowing each
globe to fall and strike, horizontally, on a block of seasoned white
oak, the distance of fall being recorded.

(_k_).--Each safety lamp globe will be mounted in a safety lamp and,
when the lamp is in a horizontal position, a steel pick weighing 100
grammes will be permitted to fall a sufficient distance to break the
globe by striking its center, the distance of the fall to be recorded.

(_l_).--To determine the candle power of safety lamps, a photometer