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Description: | 250 18 A2 ROYAL EDISWAN (acid etched on the glass envelope). 253 (written in black on the base of the glass envelope). MANU Royal Ediswan circa 1910 Ducklees Lane, Poders 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 16 candle power general lighting service lamp with a Swan double contact bayonet two pin cap type No B22/25x26 and a clear pear shaped envelope. The double filament, in the form of fa pair of two loops, are attached to nickel to platinum to copper lead in wires by the carbon tube method and each is supported by a single molybdenum wire 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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