Safety lamp it. Air is drawn in and descends just inside the glass, passing up through the flame in the centre of the lamp. The outer casings of lamps have been made of brass or tinned steel. If a lamp bangs against a hard piece of rock a spark could be generated if iron or untinned steel were employed. Within months of Clanny's demonstration of his first lamp, two improved designs had been announced: one by George Stephenson, which later became the Geordie lamp, and the Davy lamp, invented by Sir Humphry Davy. Subsequently, Clanny incorporated aspects of both lamps and produced
Safety lamp is both a source of light and a sensor. A development of the Geordie lamp was the Purdy. A galley with gauze provided the inlet, above the glass was a chimney with perforated copper cap and gauze outer. A brass tube protected the upper works, shielded them and kept them locked in position. A sprung pin locked the whole together. The pin could only be released by applying a vacuum to a captive hollow screw; not something that a nicotine starved miner could do at the coal face. Clanny abandoned his pumps and candles and developed a safety lamp which