A NEW ELECTRIC LAMP.

Manawatu Times, Volume III, Issue 57, 16 July 1879, Page 3

A NEW ELECTRIC LAMP.

Tlie Scientific Ameidcan contains an illustrated description m detail bf the' " SawyerMan Electric Lamp," which., appears, .to remove some, if not all}* ! of the ' obstacles^to the use of elecfci'icity^ ; in place otga8 Ti fpr general purposes ; ipf ' illumiiiationi The lamp itself is about the sisje and shape. .of. .an A^-gand burner^ .with, its Bhade, ; ; but the shade of the Sawyer-Man light is abell-gliifls. The source L of light is a small pencil o,f ,car- . bon, which is placed Under the r .Bhade^and near the top, the. carbon point ( being ' made ( incandescent \ by -"•the; 1 Vcurreiiii 1 passing through it, arid ; conducted fche;» By a^/rjithe*' intricate ( arrangement of wire 9 , wuich,- however, .are .fixe,d,, and .dp . not te-. qiiire to be again ' change^ or adjusted m any way.. A " ewitpli " has been devised to control the amount of 'current parsing through .the cai-bon, and at the .. saim time ., to maiiitain :a ; uniform resistance, m the sub-circaifc. Tliis, it is claimed, allows the ] division pfc the current, ; one of? the ,, moat features of the ' invention. ' The bell-glass or shade, in which the pencil of carbon is contained, is filled 'with'p are nitragen and' hermetically sealed, so that the: carbon pencil -is -not' (Jdrisumed or 'cheniiqally, attacked, but remains a permanent fixture, to be lighted whenever tne, cu-rent of electricity is turiaed on.' The : intensity ■ of the light is regulated- by the switch, the carbon, being made a dull red, a bright red,or white light, at will. The'invention of Messrs. Sawyer and Man also includes a meter- for recording the number of lights and- their time of burning-^— not the amount of electricity' furnished— : and "system "l of ■main and branch circuits, with shunts de-i vised to secure uniform resistance; ivQneJofthe objections to the «lectric light on th« score of cost has' been [the; great loss; which; results from a division' of the current, but Mr. Sawyer states that the ilium mating power of a' carbon': itf?reases iwithv vasty,; greatef rapidity: than th«. temperature,^ so ; that when? the Jight isrwell'onaiverjr slight, increase m the current increases the light, enormously. The question of the economy; of the light furnished by this lamp can. be,, demonstrated pniy by a protracted test on a., large scale.- ■* Compared » with , - the icdste tpf ;u . gas m New York^ it, j is estimated! that.-the.j electric light would-;only /costTpnft-.fqr J tie% as much, which leaves a large margin for. errors of : calculation^ . . •