Since the last time I was there they've opened a 'Lamp Cabin' on the colliery site which is a display area for the history of miners' lamps. Fascinating collection, weird and wonderful.
This one is a lamp designed by Dr. Clanny and manufactured by a Newcastle company called 'Mountain'. Made about 1835. Never got very far past the experimental stage.
These two photos show the lamp in its normal operational condition on the left and after gas had entered on the right.
The design was like a gauze lamp, but a piece of wire through the top, above the flame, held the copper skirts or shields up. If gas entered the lamp the flame would grow and melt the wire, and the shields would drop down closing the lamp off.
The design was presented to a Select Committee on Coal Mines. They reported back: "The nicety and delicacy required in the management of the wire and apparatus...can scarcely be expected at the hands of the rude miner..."
Therefore condemed as too difficult a design for the miners, so never got anywhere.
