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
Carcel lamp were that the movement operated unattended, the oil could be used to the last drop, the lamp would stay lit for sixteen hours continuously without refilling, and it provided illumination for several persons at the same time with a single burner. They were more complex devices however, and were more expensive and prone to problems in the mechanism. They were most popular in wealthier European cities. Their unpopularity was partially due to the necessity of having to return them to the (mostly European) manufacturers for repair. In 1829 the simpler Moderator lamp was invented, which dispensed with clockwork and used