The Forgotten Era of Moonlight Towers

Back in the early 19th century, the invention of the dynamo brought promises of an exciting new world ahead, but the most urgent need of the day, or rather the night, was lighting. Edison's revolutionary incandescent light bulbs had not been invented yet, but Sir Humphry Davy, who can be considered the true founder of electric lighting, had demonstrated at the very beginning of the century a method to produce light by bringing two metal electrodes very close together to produce a sustained spark. Known as arc lamps, these became the first practical electric lights. A carbon arc lamp consist of two carbon rod electrodes in free air, and connected to a source of electric current. The electric arc is struck by touching the rods together and then slowly drawing them apart to create an arc across the gap. The heat vaporizes the tips of the carbon rods and the highly luminous carbon vapor produces an intense bright light. New Orleans Riverfront electrically luminated at night, 1883. Sketch by J. O. Davidson Although the invention of the arc lamp was a spectacular feat, it became obvious that their use would be limited. The light produced by the arc lamp was too intense to be endured at close range, making them unsuitable for indoor use. Even when installed outdoors at the height of typical street lights, these lamps required shielding to reduce the glare which meant that much of their light was wasted. The city of San Jose, California, tried to solve the problem in 1881 by putting arc lights atop a 237-foot tall tower. A total of 6 arc lights were installed boasting a total light output of 24,000 candlepower. Inspired by San Jose, many American and European cities began putting up lighting towers. These came to be known as Moonlight Towers because the way it mimicked the shining moon. A single tower illuminated several blocks at once, and there was enough light to read one’s pocket watch a quarter of a mile away.