KeywordsArizona Geological Survey Bulletins
United States of America
incandescent light bulb
MetadataShow full item record
PublisherUniversity of Arizona Bureau of Mines
Description·"The first thought which occurs to the uninitiated on hearing the word 'Tungsten' is almost certain to be of the latest form of incandescent bulb. The remarkable qualities of the filament lamp, drawn from ductile tungsten, in the economy of current has caused the tungsten filament lamp to take the place of the earlier types of incandescent electric lights. The fact that tungsten can be drawn to smaller sizes than any other known: metal while retaining its remarkable strength and pliability permits of the shipping of tungsten lamps with the smallest percentage of breakage and gives long service. By its use, at least two and one-half times as much as the old carbon filament is given at half the cost for electricity and the light is white as against the orange red of the carbon lamp. The use of tungsten in electric bulbs has resulted in an enormous saving of current which in the aggregate amounts to many millions of dollars per annum. Lately, greatly improved lamps 'in which the wire is wound in helices and in which the globes are filled with nitrogen, have brought the consumption of electricity down to 0.4 to 0.5 watt per candle and have produced the closest approach to white light. These lamps are furnished in candle powers up to 2,000. Nevertheless, the total tungsten used for electric light purposes represents a very small proportion of the annual consumption. 14 p.
Series/Report no.Bulletin No. 11
Mineral Technology Series No. 5