"The "Novak" Incandescent Lamp.- Some further details are now to hand with respect to the latest addition to the ranks of incandescent lamps outside the Edison patents, and a brief note upon which appeared a fortnight ago. The inventor, Mr. John Waring, says that in all lamps where a vacuum is not employed, but where instead the bulbs are filled with a gas which does not chemically attack the carbon filaments, yet the "air washing," as he terms it, or the rapid passage of gas molecules over the highly-heated surface of the carbon (due, presumably, to convection currents), will produce rapid disintegration of the filaments; besides which a great amount of energy is carried off in the shape of heat, because of these currents or eddies in the gaseous atmosphere of each bulb. Accordingly, he employs a gas of great specific density, so that the loss of heat from the carbon may be reduced of course, care is also taken to use a gas which has no injurious chemical effect upon the carbon. Mr. Waring finds the best results to be obtained from a gas consisting of the vapour of bromine or iodine, or a mixture of both." |
