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Description: | TO BE BURNT CAP DOWN 5L/487 (black stencil on end cap). 80 V 3000 W 82 SIEMENS GASFILLED MADE IN ENGLAND (acid etched on the glass envelope). A.M. 8.E.L. 2 (with crown acid etched on the glass envelope. 1995 (written in black on the glass cane). MANU Siemens [Electric Lamps and Supplies Ltd] probably late 1930's England DES after SWAN,Joseph,Wilson,Sir. 1878 Newcastle-Upon-Tyne England This is one of two gas filled singly coiled 80 Volt 3,000 Watt ductile tungsten double filament general service lamps with Goliath Edison Screw Caps type GES No E40/45. Described previously as a light house bulb (see entry for G.1988.39 in old catalogue and dated as circa 1960 see also pre disc data sheet for same entry). This would appear at first sight to be OK but this is a lamp produced for the Air Ministry who were never involved in light house operation. The cap down position of the lamp suggests that it was not used for general area lighting such as aircraft hangers. The most likely use for this type of lamp was as an airfield beacon. The filaments are arranged in cruciform monoplanes which would give a uniform 360 degree spread and the envelope is not partially blackened or mirrored suggesting that the lamp was not used with a reflector or condensing lens. The gas is probably nitrogen or a nitrogen argon mix. The date is also suspect since by the end of the Second World War airfield beacons were electronic directional RF types. This would suggest that the lamp was produced pre 1939. The asbestos is in two forms solid to insulate the molybdenum supports and woven to insulate the lead in wires in the cane from the tuffnel sleeved neutral wires. This lamp in a glazed ceramic lamp holder GLAHM 105916 not mentioned in the catalogue entry or the pre disc data sheet. | 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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