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Description: | MADE IN ENGLAND ROYAL EDISWAN (acid etched on the glass envelope with the Royal coat of Arms). 250 8 A3 (stencil on the end cap. MANU Royal Ediswan circa 1910 Duck Lees Lane, Ponders End, Enfield, London, England DES after SWAN,Joseph,Wilson,Sir. 1878 Newcastle-Upon-Tyne England DES after EDISON,Thomas,Alva. 1879 Menlo Park, New Jersey United States of America This is a 250 volt 8 candle power 3 amp general lighting service lamp with a small Swan double contact bayonet two pin cap type No B15d/17 and a clear tubular envelope. The double filament, in the form of a pair of two loops series connected, are attached to nickel to nickel-iron alloy copper composite to copper lead in wires by the carbon tube method. The two filaments are connected in series by a short section of nickel wire in the form of a W which also serves as a support. further support is supplied to each filament by a single molybdenum guide wires both of which are on a central stem. The envelope is a hand made vacuum type with a pip or pintel. Note the "metallised" carbon filament was first produced in 1904-5 and was a double heat treatment of a squirted carbon filament giving it a glassy or metallic finish. | 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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