METALLIC FILAMENTS.

Dominion, Volume 2, Issue 606, 8 September 1909, Page 4

METALLIC FILAMENTS.

■•• Electrical,; inventors .',are ';;busy* upon .'tho .task, bf.'.pertec'tiug -,tho-'.' iifletallfo; filament lamps, which, ire revohitibh, in , electric lightiiigr''" Some.' interesting. particulars .as to: what .has'-boea flbnc, aim what-is bemg'attempted,..were 'given bv-Mr. Stuart 'Itichardsori,* City .-Elcetrioal .'Engineer,'' in 's -cliat'";w;th-'a;PoMiNioN : reporter. ■ :■'-.- / ; 'In tho first Osram, lamps tho'filaments 'were mado of'osmium,- 'it. veryj;rar6. : m6ta!, .and-:'it'?wa'3,'not"lintU ■ tho'Vrhaliufdcturer's fouM.: thai tungsten' would serve: tho pur-. •pos^'that'.the-lamps'could -be produced -at. n. commercial.:-price. now;, required is.arV'ihiprbS-ohieht in'.the process.'' At'pre-" ;Bent/tlje. tungsten-J3;_'r)aife'rißed into.a ,very andjtuTvis mixed.'with another 'matonal.it'o' : -Vervo : .aS.''bindihg,-', the 'whole forming-a .sort of. paste. This substance'is 4 : hen,,;ibreed;.-through; tiny. \ .holes,"'- and" the 'resultnigVithread /'is ''.'tho;.'.'filament of-,the' lamp.- .Heat;is then'applied, with:tho result ..that. iljo.binding.material.'is : burnt out,. and 'tho'"pa^iples' ; 'prtUrigs'tca"orc fusetl together. The filament thus formed; is very fragile,' arid ,that vis why Jtheylardps have to ..bo ;hahdiod.so. tenderly,; /and .are so. liablp- to '.breakago.' '_. ,What % ,thq.'«mamifacturers'' want "is ''a"process for drawing "tungsten 'ihto"'a sufficiently -.fine'.' wiro,.-. whioh would/-., bo miichi .less" ,'brittlb; > ;than : - ; ; .tho , present ttrarhentrs, , 'tho""dill'erence''being'-analogous to that' between;'.w'rpught.':iion:\an.d cast'-'iron.. A.process' been patented, but it is 'at present. ,too cnstly-Vfor'"manufacturihg purposes; All the lafops/nbV-.'on, the marlie|6— the:'' English; tas well' ; as; tho Germ'an makes—have -, filameilts• .'-produced. >in the manner,; described.'-..; Independently ,of tho ;wire-dta'wing .question,'--.:Mr.'.'v-Itiphardsoh':is sure '.that.the. lamps-will shpr'tly, bo considerably,cheaper''tban they.aro, at present.-. English retail prices aro;.already lower than thoso charged : hpre.'\ Mr.: Richardson said ,tho re-' ..v.enue| of..:.thV'electricai;.department was still BUfFerilig' from''tlie',reduction which people 'hay6;effectod. ; lightijig bills, through the use' lamps, but ho anticipated :th'at';'iif'iricrisg'od 'cprisamption ; would in duo time the. loss." ':. ... -.. . ': SJr.rßiehard/on; -mentioned \ that tungsten', is found in' ; Naiv-'Zealand; thore beinp; a con- ; sidorabl<r-quahtity;'"in : Otng'b. In this' con-' nebtion it'is^intorestirig'to noto that tho Rcofton Cllanihe'r 'pf Commerce, as ■ reported , inlayWest'Cpist, paper',, recontly received a • letter from" the Gantoxbur.v .Chamber of Com mercey inquiring about' wolframite and scheelite ores, : ; frbm which tungsten metal' is ■ oi--1 tractod. -The letter, stated that there; is a ready sale in ' England .fdr these ores,' and. the writer's askod to bo put'into;conirhunication with exporters .of-.samo. ~-.-.,' ... '-