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Description: | PATENT GEC LTD 8 OSRAM 200V GASFILLED 60W 08 MADE IN ENGLAND (acid etched on the glass envelope). SGS1 (etched on the glass envelope) MANU General Electric Company Limited of England. circa 1925 Osram Works, Hammersmith, London, England. DES after SWAN,Joseph,Wilson,Sir. 1878 Newcastle-Upon-Tyne England This is a 200 volt 60 Watt gas filled general lighting service lamp with a standard Swan type two pin bayonet end cap BS25/26, wreath filament and a clear pear shaped envelope. The single ductile tungsten coiled filament is clinched to the nickel part of the lead in wires which also act as the main support. Secondary support is in the form of five fine molybdenum crooks fixed to the central glass cane. The gas is probably a mixture of nitrogen and argon. 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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