1943 Philips 15S58 (15 W / 110 V)

The 15 W squirrel-cage filament lamp shown here was made during WWII, in a period when the Netherlands was under German occupation. At that time Philips operated on limited resources and had difficulties getting the raw materials necessary for the production of their lamps. This difficult situation got significantly worse after December 6th, 1942, when the British Royal Air Force bombed Philips’s factories in Eindhoven during operation Oyster. As a result, simpler lamp designs that had been phased out years and even decades earlier were re-introduced while some other products were simply outsourced. Naturally, the primitive and inefficient lamp designs were abandoned after the end of the war when production could resume under normal conditions. The construction featured in the present lamp dates back from the origin of practical tungsten filament light sources in 1904, a design that was mostly abandoned in the second half of the 1910s following the release of the first coiled filament lamps in 1913. Due to its low wattage and the configuration of its filament, the lamp operates under high vacuum which is maintained by a red phosphorus getter visible on the filament support stem.