Early Arc Lights
The electric light debuted in New York City in 1880. But even "the city that never sleeps" had only 1,500 electric street lights to its 26,500 gas lamps by 1893. The earliest electric lights were in the form of arc lights. These lights evolved throughout the 19th century as the dominant form of lighting. Due to their undiffused light and noisy, sputtering sounds, the arc lamp was largely abandoned in the 1920s. Early arc lamps had straight posts and clear glass housing, often resembling the gas lights they replaced. The designs were decorative, particularly in commercial locations. They generally date from the 1880s-1910s.
In the pre-automobile years, straight posts with single lamps were found, as seen in the leftmost image below.
When lamps are paired and extending from brackets, as seen in the rigphpost image above, they likely date after the widespread use of the automobile. As well, groupings of lamps were often found on bridges or in front of civic buildings in this time period, as seen in the image below. They generally date from the late 1910s to early 1920s.
Occasionally, in the late 1910s and 1920s, arc lights were strung over busy thoroughfares in a large arch, as seen in the image below.