Infra-Red Heat Source

Ref. M3

This undated item goes probably back to the early decades of the 20^th century.

The heat emitting bulb is of a very archaic design, judging from the pointed vacuum tip on top of the bulb. These tips disappeared from the industry in the twenties. The filament is equally of a very archaic type. It is of the pre-tungsten era, totally made of a long widely spaced helically wound carbon wire. It is of a low wattage (110V).