ROYAL EDISWAN TUNGSTEN FILAMENT 130 VOLT BULB, 1930's

Bulb used in Trolley Buses and Trains up to and during the 1930's.

Your comments:

• Correct description. More accurately, this one can be dated as between about 1913 (when the red coloured "Dumet" wire which leads through the glass was introduced to replace platinum wire), and 1919-1920 (when the glass evacuation tip on the bulb crown was relocated to inside the lamp cap). This one would have been made at the Ediswan works in Ponders End, Enfield
  .......... James Hooker, Aarschot, Belgium, 30th of April 2011
  
  

A0698