All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

Coming of Electric Lighting 231 the new filament was able to do for the pockets of those who preferred electric lighting—reduced the consumption of current and consequently the cost thereof, from 50 per cent, to 70 per cent. By the discovery of the filament lamp gas and electric lighting were once again reduced approximately to level terms. But the lamp in which the rare earths were directly utilised was one of which great expectations were entertained, but which did not survive the metallic filament incandescent rival. It was of the glow-lamp type, the filament comprising a composition of the oxides of zirconium and yttrium. But this filament suffered from the disadvantage of requiring heating- up before it would conduct electricity. A certain period of time was required for this purpose, fine platinum wire wound round the filament comprising the heating agent. The light emitted by this lamp was a decided improvement upon the carbon incan- descent lamp, while the general shape thereof gave it the appearance of being a miniature arc-light. It commanded attention because of its lower consump- tion of electricity per candle-power, which at first was considered to be more than adequate to counter- balance the few seconds occupied by the preliminary necessity to heat-up the filament by switching on the current. But before the Nernst lamp, as it was called, could be developed, it was excelled by the new arrival which consumed even less electricity per candle-power, and thus it lapsed into obscurity. The new metallic filament lamp, especially in its high candle-power forms, threatened to usurp the older and well established arc-lamp, even for general lighting purposes. But progress was not stationary