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Description: | SERIES 0 .302 amp 125V 40W D.72 Osram PATENT G.E.C., LTD MADE IN ENGLAND (acid etched on the glass envelope). H (stamped or moulded into the top of the cane supporting the element). MANU General Electric Company Limited of England. circa 1924 Osram Works, Hammersmith, London, England, DES after SWAN,Joseph,Wilson,Sir. 1878 Newcastle-Upon-Tyne England This is a 125 volt 40 Watt general lighting service lamp with a standard Swan type two pin bayonet end cap BS25/26 and a clear bell shaped envelope. The single ductile tungsten squirrel cage filament is cliched to the nickel/iron lead in wires. It is supported by a lower set of five molybdenum wires and an upper set of six mounted on a central glass cane. The support wires are in the form of fine crooks not loops.The first tungsten filaments were developed circa 1906 using a process similar to the squirted carbon filament but a ductile tungsten process, by which tungsten powder is compressed and then forged into billet before being drawn through a series of diamond dies, was developed in 1909. The envelope is a machine made vacuum type without a pintel or pip. The bulb being evacuated via a hole blown in the base of the cane. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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