Show I Cutting Our Lighting Bills in Two 1 A LBERT w W. W DEININGER has A ALBERT been been calculating for tor the Scientific Scientific American the relative cost 0 of different forms forma of light and the way that modern Inventions have cheapened cheapen cheapen- ed lighting Using gas he ho takes the theol ol open n flame as s used prior to 1905 to represent the unit of gas consumed to produce a j certain power candle-power and finds that the upright mantle with fluted flat cone reflector consumes the Invented in inverted inverted in- in vented mantle with prismatic reflector reflector reflector tor consumes Using electricity and taking as the unit of current consumption per candIe candIe candle can can- dIe dle power the carbon filament with opal cone reflector he finds the gem V I lamp mp with opal cone reflector consumes con con- MImes and the Tungsten filament with prismatic glass glas refi reflector consumes con con- V The common open flame fiame burner he says consumes 5 cube feet feet of or orgas it gas per hour whIlo while the ordinary in inverted in- in mantic mantle burn turner burner r consumes es 3 cubic feet It natu naturally fo follows lows therefore that Uia Iho thO gas consumption will be r re reduced reduced re- re 40 p 40 per r cent and the Intensity at of t illumination be 54 54 times s as great if open flame burners burner are replaced ed br by inverted man mantle le burners with prismatic t c glass glass' reflectors V. V 1 And at the 1 resent present time using Tungsten lamps with prismatic tor tors obtain 28 times as much effective effective ef- ef illumination for the same power as we could obtain using carbon lam lamps lamp's with opal cone reflectors He calculates that gas lighting costs costa only 74 per cent of ot the cost prior to 4 I 1905 and that el electric lighting costs costs j only per cent of the cost prIor to to j 1905 At present electric costal lighting I times Umes as much as gas lighting tha th thai replacement cost of or gas mantles and and Tungsten lamps Iams being very nearly the the same The limit of or illuminating efficiency by by- incandescence is' is is is' believed to be at atI I hand he lie sa says sas s. s The next era is b believed be be- i I to J bo be e one of luminescence o on oa l lI which light will b be obtained by causing g gas gas in a bulb to g glow ow by pas passing ing an aS an electric current through h It v vAnd And he ho predicts that within a few years electric le lighting lills will be c cu cut i in two bec because use only half haIr of the powe used used at present present will be required and andas and aud audas gas as bins bifia Jr frill I be considerably lower ri because The mantle type cf of light re re- re quires heat at only an and therefore a chea cheap g gas o of olow low illuminating tIrig efficiency ma may mai be us used d. d t t. t i V |