EWJona 10S50

Shown here is an early decorative lamp, made in the 1910s and coated with a red lacquer. Typical of incandescent lamps of the time, it features a straight tungsten filament operating in vacuum, and a straight-sided glass bulb with an external exhaust tip. Interestingly, the lamp is designed for a 20-V operation, probably in a light string. Six of such lamps are needed for an direct operation on 110 V mains with a 10-V safety margin.