The Adams-Bagnall Electric Co. was organized in 1895 by Thomas Adams and E. J. Bagall, both formerly associated with the Swan Lamp Manufacturing Company of Cleveland, which was owned by and manufactured incandescent lamps for the Brush Electric Co. of Cleveland. The Brush Electric Co. was founded in 1880 by Charles F. Brush, the inventor of the first practical arc light system in the United States, which was used extensively for electric street lighting in the 1880's. Brush, along with Thomas A. Edison, is considered the "father" of electric light. It appears that Adams and Bagnall left the Swan company because of its closing in 1895 due to the acquisition of the Brush company by a predecessor of General Electric.
While at Swan, Thomas Bagnall had developed the Adams-Bagnall arc lamp, which used the clutch mechanism patented by Brush to control the movement of the carbon rods, but operated at on constant pressure (voltage). Constant pressure operation enabled arc lights to be integrated into incandescent light systems and to be controlled individually, like incandescent lamps. Prior thereto, most arc light systems operated on circuits separate from incandescent lamps and at constant current (amperage), which necessitated high voltages for a series of lamps and made providing for the turning on and off of individual lamps difficult. Bagnall's lamp also incorporated the latest development in arc lighting the early 1890's, enclosure of the gap between the carbon rods in a small inner glass globe, which increased the safety and brilliancy of the arc and extended the life of the carbon rods to up to 150 hours (the carbon rods are consumed in the operation of an arc lamp, requiring the "trimming" of the lamp periodically with new rods).
The Adams-Bagnall lamp appears to have been a popular lamp around the turn of the 20th century, holding its own against the arc lamp offerings of G.E. and Westinghouse. A 1904-1905 catalog of the Illinois Electric Company, a Chicago electrical supply house, that I have shows your lamp. It's described as "suitable for high ornamentation for inside service" as well as outdoor service. Models are offered in steel and copper housings, for operation on direct current at 110 and 220 volts and on alternating current at 100 to 120 volts, and fitted with either a clear or alabaster globe or a metal reflector.
The Rushlight Club, Inc. © 2020
Rushlight Club Home Page www.rushlight.org