Safety lamp, Cambrian, Clanny type (bonnetted), Moore's pneumatic lock, maker: Thomas and Williams, Aberdare, marking: makers name, 1901

Safety devices were increasingly employed to prevent accidents arising from careless or improper use of safety lamps in mines, one of the most frequent temptations being for the miner to relight his own lamp in the working place. This lamp embodies the pneumatic lock patented in 1896 by Mr. J. Moore. To enable the miner to inspect the gauze of the lamp, which is of the bonneted Clanny type, the bonnet can be screwed off after it is lit, but it is locked by one of the pillars caused to slide endwise when the reservoir is finally screwed up. The latter itself is locked by a piston bolt in the cage shot by a spring into a hole in the reservoir; the bolt can only be withdrawn by exhausting the space above it by a suction pump.