A NEW ELECTRIC LAMP.

Dominion, Volume 1, Issue 235, 27 June 1908, Page 13

A NEW ELECTRIC LAMP.

THE METALLIC FILAMENT BULB. The last chapter in the romance of electricity is not yet. After electricity for lighting purposes became an established fact, the scientists of America and tho old world began experimenting in a variety of ways, and with all the material the world could offer on the construction of the lamp that was to give the best' result. The filament in the glass-enclosed vacuum was discovered as one of tho means to create light at a junction between two wires, and then experimenting continued until tho carbon filamont was produced. Up to that time various metals; raro and, otherwise, were tried, some with moderate success, but the carbon filament was considered to, bo so successful that for a long time no improvement, as to the character of the filament, was attempted, Some years . ago, however, experimenting with metals was. made a subject for 6tudy in some of the big electrical laboratories. Tho outcome of these has been tho production of . a metallic filament lamp as, much suporior to tho ordinary carbon , lamp as is the incandescent burner and mantlo to tho old-style gas-jet, and strange as it may seem, tho inventor of the " Osram " metallic filament lamp, who has effected revolutionary improvement in the application of olectricity for lighting purposes, is the famous Welsbacfi, tho inventor of the incandescent burner and mantlo. Ho has solved the metallic filament problem by blowing out. long loops of tungsten (one of tho rarer metals), which loops are so long that the vacuum glass bulb in which they are contained have tho length again of the ordinary carbon filament bulb. There are four'''of these loops in each bulb, each suspended from the top and supported midway by a dolicate glass bracket projecting from a central glass drop. The City Electrical Engineer (Mr. Stuart Richardson), who has been watching the development of the new idea for some time through the medium of the, technical papers, imported 'a , number of tho new lamps somo time ago,iand has been> quietly experimenting with tnem. Not a man easily carried away with anything new, Mr. Richardson, and with him Mr. Cable (Assistant Electrical Engineer), and Mr. Geo. Lachlan. (supervisor of

electric linos), are convinced that the Osram jamp is going to revolutionise elcctrio lighting, on account of the brilliant light that it gives on a much smaller consumption of power than is used by the carbon lamp. This was demonstrated in the testing-room of tho Harris Street power-bouse last evening. On a 16 c.p. lamp being fitted to the tester the dial showed that it was drawing 62 kilowatts, whereas a 50 c.p. Osram lamp, giving a light almost too brilliant to gazo at, only required 50 kilowatts to for its need's. To largo consumers rif electric light this means a better light at half tho cost. In one test made at the municipal power-house a 16 c.p. lamp burnod for 16 2-8 hours on one unit of power, against tthich', a 50 o.p. metallic filament lamp burned for 20 hours on tho same amount of powor. The testing-room at the Harris Street works . has been lit with three 50 c.p. Osram lamps for some time past. Ono burnt out after having burned for 14661 hours, the other two are still intact, and when lit last evening against a perfectly new lamp showed very little depreciation in lighting power. Furthermore, thq metallic filament lamp does not blacken as readily as the carbon filament lamp (which unliko the now lamp absorbs more current ps ft ages). The only apparent weakness about ' the "Osram," according to Mr. Richardson, is jts fragility, and the fact that it niUßt hang (not stand) vertically, In any other position tho filament is'apt to break. The "new lamps cost about 6s. 6d. each, instead of tho homely shilling' (as .is the case with tho carbon lamps). A few of the new lumps are boing tested for street lighting in Brougham Street, and a city restaurant-keeper, who has been supplied with them, has boen- amazed at the saving effected in his bills. Tho lamp is equally effective with the direct or alternating, current, arid does not reflect the fluctuations in the pressure as do tho lamps in general use.

When posterity balances the account of the good or tho evil that England has done to India, the introduction of organised horseracing and its. attendant gambling will bulk very largely on tho debit side of the account. In Bombay even the children are bitten by the craze for risking ,on a race the rupees which they can ill afford to lose.—"Gazette," Bombay.