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1928 - a new lamp fitting into a small reflector fastened to the miner's cap, is operated from a compact two cell storage battery strapped to a belt about the miner's waist

MINERS SEE A NEW LIGHT

CD 1964007 E&MP25.062

Electric Lamps

May 16, 1928

A new two filament incandescent lamp for miners, assuring adequate illumination throughout the day, has been developed by engineers of the General Electric Company at the National Lamp works here.

The lamp, fitting into a small reflector fastened to the miner’s cap, is operated from a compact two cell storage battery strapped to a belt about the miner’s waist.

The two filaments operate at different intensities. The major filament, giving 14 beam candlepower of light, is used until it fails. Then a simple switch, attached to the side of the lamp, is turned which throws the current into the low candlepower emergency filament.

This furnishes sufficient illumination for the worker to finish his day’s work when a new lamp can be installed at the time the equipment is turned in for rechanging the battery. The emergency filament is rated at low candlepower, assuring longer life than if the second filament were of the same candlepower as the first, which discharges the battery in about 12 hours. It is possible to operate the emergency filament for 30 hours or more, should an accident keep the miners underground for an extended period.

In the past, lamp failures have often occurred when they are being used underground by the miners.

C.E. Egeler, engineer of National Lamp Works explained,  It is not a practice at mines to provide a place below the ground for replacing burned out lamps. Either the miner must be furnished with another equipment, or he must go to the lamp house on the surface to obtain a new lamp.

Usually in the past, he stopped work for the day with a loss both to himself and to the mine operator.

NOTE: Close up of the switch operating the two filaments of the lamp.1928 - close-up of switch operating the two filaments of the lamp

The introduction in 1919 of a cap lamp equipment having two Mazda lamps was a natural development. Only one lamp could be burned at a time, and the other could be turned on should the first fail. Now this condition has been corrected by the two filament lamp.  







Original Caption by Science Service
General Electric



National Museum of American History

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