SCIENCE NOTES

Hutt News, Volume 3, Issue 5, 26 June 1930, Page 6

SCIENCE NOTES

Flame through stone -wall. A flame -Hot enough to oat its way into ail iron safe like :uv auger into cheese—even hot enough, it Is prdbable, to melt;-a liole in a stono wall as a vo2-, f-ano melts out rock to farm lava—has Wen invented by Dr. TVank M.: Strong, of Syracuse Universty. The .heat producer of the new .supei'Ttoreh is porvrdered, motailis aluminium burning in a blast of higQi pressure oxyg^ gas. .That many tnetaMe' dUistsi aj:e:! combustible is well knpwrr tP chemists, says i Pop«]ar Science. .Povrdefed . mangesiuin' < is the esseritial cpnstttutejit of tfee well- ! khown flashlight powder used by photographeTrt. Iron dust niay be set on lire in an atoniiser '-, of; oxygen with a brilliant pyrotechnic display. Dust of nxetalii"e th&riuiii.. under: proper conditions, Wiß set itself on lire brilliantSy and Jh<rtily •by mere contact with the air, as hia* been proved byD.r. Harvey Rentsehler, president of the 'New. York Electrical Society and, research of the Westiitghousei Lamp "Works. .-■; Aidmiiiiuin dust aa a iieat prod^eer: is already fainiHariri' the tuixt.ur,€i ca>lled themiite, in which. th« ' powdered aluminium "is mixed with powdered oxide of ifpii. When this mixtufe is ignited the aluininitan dust exchanges ipartners cJnemically with the oxide of iron, the aluminium and the oxygen combining wfoile the iron is set free as molten metaiJ. In this case not all ofilie •energy of the combination between aliiminium and oxygen can be set free. as heat, for some of it must be used to decompose the oxide of iron. This I loss of Jieat Dr. Strong avoids by providing oxygen gas with which tih.e aluminium can combine. k In IXr^ Strong's torch a stream ofalcminium dust is mixed mechanically with

a -stream of high-pressure oxygen. TPhis mixture., .supplied through eight separate pipesr, is f ooussed on the flaming poiriC-T of tho torch. So great is the affinity q*-^"' aluminium for oxygen fhat the mixtorl may bo touched off with a match. The temperature attained , i.s gTeat enoiigh, Dr. Strong reports, to cut throiigh any known solid substance.