Oldham miners electric safety lamp, type C, with magnetic lock and accumulator

This is a modern electric safety lamp of the standard pillar type. The lamp body is of cylindrical construction and is made of pressed steel. A strong cylindrical glass, closed at the top, surrounds the light bulb and is itself protected by four steel pillars equally spaced round its periphery. The bottom of the case is of aluminium and screws into the upper portion, being locked in position by a magnetic bolt. The accumulator is specially designed for the use of liquid electrolytes although solid electrolytes are supplied when desired. The lamp gives about 1.0 candlepower for 9 to 10 hours ' continuous lighting.