GAS ILLUMINATION.

Hokitika Guardian, 28 February 1923, Page 1

GAS ILLUMINATION.

I'KCKNT ITIUMIKSS During the recent progress ol gas illumination there have been lew summaries of developments, and a recent paper by Mr W. I. Knudeman. of the Croydon Mas Company, road bet ore the Illuminating Engineering Society, brings the history of gas ightiiig 11]) to date. The stages of progress are illustrated by the following progressive types of gas appliances: Plat Hattie burners .upright incandescent, inverted invandcseout, superheated (small mantle). ’Multiple burner lamps, and, lastly, high pressure lamps. Concomitantly there have been the changes itt tin standard of gas front illuminating calorific. and the increase of pressure I it.m live-tenths to till inch required for the Hat flame to tin., twenty-five to thirty-tcnlis now required lor a full mantle. Throughout the period, progress may he expressed in tt nut' ol increased caitdlt power per cubic foot. With flic old 10-candle power gas. Hat lhim.es gave from 2' to 2.0 candles per cubic loot. Specially proportioned Argued burners, inerrusod this value to ;t,,T, Ingenious devices for preheating the gas 'by its products of combustion raised tin figure to. in some cases 8. Tiie methods, however, were cumbersome, and only served to suggest ideas which have since rendered excellent service. In ISK.T the incaiuhxeut mantle. heated b.v the high temperature I’umsen tin me. gave us lb candles per cubic loot oI "II caudle” gas. while the Kern burner, inducing more, primary air bv a longer chimney, attained IK caudles. Kurt her progress raised the p. .lire to -Jit. and also t mibled larger units ol 3(K> to (I li> candle power t„ he Used.

Inverted burners made their appearamo in p.lOtl .and a normal size now ~ dot, uf gli candles per cubic (mii. Larger mantles introduced in |!11 o attained a maximum efiicicitcy ol .111 i a miles, and represented the most advanced form ol low pressure gas lamp.

The most recent dcvcloomciit ill lov on ssuro gas lamp const ruction involves Mi provision of a superheater lor pre healing the mixture of go- and air. the use of small mantles in cluster form and the use of a single gas and air I epilator lor all the burners. (’reheating is now- generally recognised as civil!:.: higher llatno temperatures. ami. therefore increased illumination. Small mantles oiler advantages over large ones, in inerted strength and life, while small mantle, can he mail • to tit Heim more varlly. Again, -Imrl ~. .till. H lulc large Hemes t>-nd ~ tSti adim favour-. Ibe .mail leant h The advantages oi a

single i'ont rol arc obvious, a slight tuni of it single tap one. way or the cth< r serving to bring the lump into its best condition. While tin' lat-.''i forms of low pressure lighting units ciuhndving .sui’cr--I|.'ated multiple hunters attain a duty |l) eatidlt s per eithie foot, the "high ail"," system oll'et's tie allcrmit'n '■ method of increased (lame ti itiperiittil'e and greater hrigl,..t -s of the mantle, ill Ihe most gilteral system a positive votary compressor raises the pressure of the gas to 31 h per square inch. This siiUices to give sullicieni velocity to the m : , s ami air mixture to enable the || mm to remain “siilf" and not li-’b' bark. Increased aeration induct« a shorter ami bolter llame. but the system embodies three methods of intense

lii-ation. viz., increased gas consumption for a given sire of mantle, men pie tv aeration, and preheating "i the gas and air mixture prior to < "O: ImsLimi. Tim e.mibii>alion ol Dmirineiido, leads to the highest gas lightin<_r ii{licii*iicy yet nt.tji {;:> .unllrs per niM»* loot.