A NEW LAMP.

Press, Volume LXIII, Issue 12897, 31 August 1907, Page 2

A NEW LAMP.

MORE LIGHT AND A REDUCED COST It eeems to be~th*e fat© of the gas and electrical industries to stimulate each other, and to benefit their customers in consequence (says the London "Daily Telegraph" of the 18th July) It tv the inrention of the incandescent electric Ump that led to the invention of the incandescent gas mantle. So keenly did the electricians feel the results of the competition witn the «as mantle that the active> minds of numy scientist, were quickly at work, in order to .eek out eomething Zrl eoononiic-l than the carbon filament for the ordinary household electric lamp. When the Welebach mantle was produced, the gf*™* t ?' lighting was increased to four.times its oricinal Talue, and to-day there are 3y D hundred's of. these lamps being supplied by *£« «" W panles for lighting F^'jjf 1 would have ken done by electric lamps. During the last two or three years, electrical engineers, hove iaXJd with great interest, and have freely discussed at the meetings of the Seal societies, the new elect™, hmps in which metallic filaments placb those made of carbon. Ass leneral rule, tho lamps have received treat praise from those most quahfiea to judge. Economy has been proved to result when such lamps are used. Hitherto osmium, tantalum and zaconium have been chiefly adopted tor such filaments. Curiously enough, Dr. Aver. of Weisbach, the tamous inventor of the incandescent gas mantle, was the first to produce a metallic filament electric lamp, and he used osmium as a basis. One of the companies with which Dr. Aver is closely connected has now produced an electric lamp, the metallic falament of which is of a material named osram, a comparatively ch63p metal, which is easily obtainable in this country. ►Several tests havo been recently made on lamps constructed # with this filament on both alternating and continuous current circuits. The efficiency is claimed to be four times that of the carbon incandescent lamp. The promoters of the new invention are so oertain of its immediate success that they are building a largo factory for their manufacture in this country. Like, tho incandescent gas mantle, the Osrnm electric lamp will cost more than its predecessor, but it is said to hove twice the useful life of an electric lamp with carbon filament. The test referred to above shows that with one Osram lamp of 32 candle-power, and one carbon lamp of 16 candle-power, there is a very great saving per . thousand hours in favour of the new invention. With electricity at 4d per unit, the saving figures out at 4s Bd. When the current is at 6d per unit, the 6avtng is 8s Cd, and at 8d per unit, it is 12s 4d. An even greater saving is shown "if the comparison be made for two Osram lamps of 32 candle-power, and one 200 volts 32 candle-power carbon lamp. In this case, the consumer gets double the light, and with current at 4d per unit saves 16s 7d, and at 8d per unit saves 37s lid. It should be mentioned that with many types of electric lights, there is a considerable drop in candlepower after a certain number of hours, but the Osram lamp appears to maintain its candle-power to within 3 per cent, of the original for «uch an extended period as 1000 hours. As far as we are able to traoe from on examination of many records published in the technical papers, this ie very much better than the results obtained with any other electric lamps. There are oases on record where the life of the lamps has been as much as 3000 hours. There seems to be every reason to believe that, as soon as the new factory is in working order in this country, and the householder has become Aware of the advantages of the new Ught, there,will be « great demand for this method of illumination, pofcsibiy those interested in the gas industry will then be stimulated to do something better. And during this strenuous competition, the householder benefits. Each year the price per unit of electricity is reduced, because of the more economical means of generating the current. Hitherto there has been an enormous waste, not so much in the proo&s of converting the heat of the coal into electric power, as in changing the electrical energy into the rays of light. Scientists have been working at tho problem of securing greater economy in this last process for many years, and they now seem to have produced something which should at least please the man who prefers to havo i his home illuminated by electricity.