CD 1964014 E&MP25.072
May 10, 1937
At the top is shown enlarged silhouettes of a portion of a new high-efficiency tungsten filament for 60 watt Mazda lamps;
in the center, a section of coiled filament as has been used in 60-watt lamps,
and below the filament is a curved strand of human hair similarly enlarged.
Original Caption by Science Service