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Author Topic: Patent Dates on Lamp Bases  (Read 2176 times)

Offline Ed Covington

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Patent Dates on Lamp Bases
« on: March 11, 2002, 08:35:00 am »
During the first two decades of the 1900s it was common to find GE-related lamps with patent dates stamped on the bases. This was especially true if the lamp had a skirted base. For example, the GE Meridian lamp had two dates on the base: Nov 8, 1904 and Nov 22, 1904. Both carbon and tungsten filament lamps displayed these dates. Even a carbon lamp that did not have a skirted base had the date Nov 8, 1904 stamped at the lower end, near the center contact. Both patents were granted to Alfred Swan, youngest brother of Sir Joseph Wilson Swan. The Nov 8th date carried the U. S. Patent No. 774,404 and the Nov 22nd date carried the Patent No. 775,689. Both patents applied to the base design or its manufacture.