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.