Safety lamp

Safety lamp, Clanny, (bonnetted), use: officials, maker: J. Davis and Son, Derby, marking: makers name, 1889

This lamp is modified specially for fire -triers' use. Air for combustion is admitted through a number of vertical holes in the ring between the glass and the bonnet; above this is a corresponding ring which can be rotated slightly so as to cut off the supply and retained in that position by a vertical bolt springing into it. The feed air must then enter through holes in the top of the bonnet, which has an internal shield to prevent the feed and foul air mixing. The lamp is made wholly of non-magnetic materials and has a silvered copper reflector, which features make it also suitable for use in mine surveying. A vertical screw lock is fitted, but there is no lock to the bonnet. This pattern was also made as a Mueseler- and a Marsaut-pattern lamp.