American Swan Carbon Filament Lamp

Following the establishment of the Swan Lamp Company in Britain, the inventor of that lamp was swift to establish his manufacturing operations around the world. The American factory was established at Boston in 1882, but by 1885 had been sold to Charles Brush, who was eager to get into the new business of incandescent lamps to complement his existing strengths in carbon arc. The company continued to be known as The Swan Lamp Manufacturing Company, but it was in fact a subsidiary of the Brush empire, and in 1885 the incandescent production was transferred to Cleveland, Ohio, where the company rented space from Brush.

This lamp appears to be of a model produced between about 1893-1895 at the Brush works. Lamps produced by the company during the earlier years are quite distinctive because of the so-called goal-post stem design that supports the filament. However this model has a simplified construction employing a flared stem tube, which was first introduced in 1893 to facilitate the operation of sealing into the bulb. Rather than pinching the wires through the flare tube as was done by competitors, this Swan lamp retains a modified version of the goal-post design in which the leadwires are formed into a Y-shape, to match the narrow diameter of the flare tube. That assembly is then fused into the open end of a glass bulb.

The filament is made by Swan's squirted cellulose process and has been attached to the lead wires with carbon deposited by heating the joint while immersed in a liquid hydrocarbon. The cap is not Swan's own design, but is of the Thomson-Houston pattern, made so as to allow Swan lamps to be used in the installations of its competitor.
Manufacturer: Swan Lamp Mfg. Co. Division of Brush
Lamp Power: Approx 90 Watts
Lamp Voltage: 100 Volts
Lamp Current: 0.9 Amperes
Cap Type: Thomson-Houston (small) Fibre Insulator
Bulb Type: P-60 P-19 in eighths/inch
Bulb Finish: Clear Soda-lime glass
Filament Type: Squirted Cellulose Deposited joint
Atmosphere: Vacuum No getter
Luminous Flux: 201 lm 16 Candle Power
Luminous Efficacy: 2.2 lm/W 5.6 Watts per Candle
Beam Intensity: N/A
Beam Distribution: N/A
Colour Temperature & CRI: CCT: Approx. 2000K CRI: Ra 100
Chromaticity Co-ordinates: CCx: 0.527 CCy: 0.413
Rated Lifetime: Approx 800 hours
Burning Position: Vertical only (to avoid filament sag)
Overall Length: 140mm 5¼ inches
Light Centre Length: 82mm 3¼ inches
Factory: Euclid, Ohio U.S.A.
Date of Manufacture: c. 1893-1895
Original / Present Value: Unknown Unknown
 
References: 1) The History of the Incandescent Lamp, John Howell & Henry Schroeder, The Macqua Company, New York, 1927, pp.165-166.
2) Incandescent Lampmakers in Cleveland 1884-1905, Early Incandescent Lamps website, E.J. Covington.
3) Location of the Swan Lamp Manufacturing Company, Early Incandescent Lamps website, E.J. Covington.
4) An Enquiry for Lamp Historians, Early Incandescent Lamps website, E.J. Covington.
5) History of the Adams-Bagnall Electric Company, The Incandescent Electric Lamp 1880-1925, E.J. Covington, NELA Press, 1998 p.10.
6) History of the Fort Wayne Electric Light Company, The Incandescent Electric Lamp 1880-1925, E.J. Covington, NELA Press, 1998 pp.10-15.
7) History of the Fort Wayne Lamp Company, The Incandescent Electric Lamp 1880-1925, E.J. Covington, NELA Press, 1998 pp.15.
8) Cleveland-Based Lamp Manufacturers, The Incandescent Electric Lamp 1880-1925, E.J. Covington, NELA Press, 1998 pp.15.
9) Brush-Swan Lamp of 1887, Past Technology Collection, 2000.
10) Brush-Swan Lamp of 1890s, Spark Museum Collection.
11) Charles F. Brush, Biography by Jeffrey LaFavre.
12) The Brush Electric Company, by Jeffrey LaFavre.