Decorative Enamel Bowl 50-GA
The 1950s marked the beginning of a major extension of the range of ordinary incandescent lamps, with bulbs having new shapes and finishes for decorative applications. It was the goal of the lamp manufacturers to add value to their products so as to earn better margins, such as were being achieved by their colleagues in the luminaire business.

In 1946 GE pioneered the introduction of ceramic glazes fired into the bulb surface, which allowed ordinary mass-produced bulb shells to be economically coated with a coloured finish. In 1949/50 new soft pink and ivory colours were introduced together with a completely new bulb shape. The so-called 'GA' style is a combination of the G and A shapes, and was offered in two sizes of the 50 Watt GA-25 and the 75 Watt GA-30.

Rather than applying a flat colour to the whole bulb surface, only the bowl is coloured and it features a pattern of concentric rings. It is not only decoratively-inspired, but was scientifically designed by GE's lighting applications engineer, Matthew Luckiesh. The coated crown delivers a soft glare-free light downwards, while the frosted upper surface allows approximately 2/3 of the light to efficiently uplight the ceiling. The result is an elegant lamp whose efficacy is not significantly reduced below that of the ordinary inside-frosted lamp. The GA lamp proved especially popular for many years, but by the mid-1970s its shape had fallen out of fashion and was replaced by other decorative designs. It was briefly joined by the 'Celeste' lamp from 1959-60, but that was also discontinued after only a few years as consumer preferences shifted towards larger decorative luminaires that contained low-cost standard A-shape lamps.
Manufacturer: General Electric U.S.A.
Lamp Power: 50 Watts
Lamp Voltage: 120 Volts
Lamp Current: 0.417 Amperes
Cap Type: E26s Aluminium + Vitrite insulator
Bulb Type: GA-80 GA-25 in eighths/inch
Bulb Finish: Inside frosted Pink enamel coating
Filament Type: C-9 Single coil wreath
Atmosphere: 95:5 Ar:N2 Red phosphorus getter
Luminous Flux: 600 lm
Luminous Efficacy: 12.0 lm/W
Beam Intensity: N/A
Beam Distribution: N/A
Colour Temperature & CRI: CCT: 2700K CRI: Ra 100
Chromaticity Co-ordinates: CCx: 0.460 CCy: 0.411
Rated Lifetime: 1000 hours
Burning Position: Universal
Overall Length: 113 mm 4 7/16 inches
Light Centre Length: mm inches
Factory: Youngstown, Ohio U.S.A.
Date of Manufacture: August 1958 Date Code: 32 . .
Original / Present Value: Unknown Unknown
 
References: 1) GE Lamp Catalogue, USA, 1960, p.15
2) GE Lamp Catalogue, USA, 1975, p.16, last known listing