The Brief Reign of Arc Lamps and Moonlight Towers in the 19th Century

By Wesley Fenlon

Before incandescent bulbs became commonplace, dramatic moonlight towers watched over cities, lighting their streets with the powerful beams of arc lamps.

History of the early days of lighting and electricity almost always focuses on Thomas Edison and his incandescent lightbulb. And quite often--especially in the last decade--that narrative has shifted to champion the underappreciated Nikola Tesla and his accomplishments. Fewer people have focused on the popular uses of electricity that preceded them both, like the arc lamp, which sits at the center of a great piece from The Atlantic on the history of moonlight towers.

The Atlantic's Megan Garber writes about moonlight towers, which were, for a brief time, popular light sources in American and European cities. The towers took name and inspiration from the moon thanks to their powerful beams of light shining down from above--often high above, as the towers could stand as tall as 300 feet.

New Orleans circa 1890. Image via

But the power source was electricity, not the natural light of the moon. Each tower was topped with 4-6 carbon arc lamps, which create an arcing current between two rods of carbon. The resulting light was incredibly bright and also incredibly hot. Low-tech Magazine writes "An electric candle typically produced a light of 1,500 to 6,000 candlepower, which corresponds to the output of 11 to 43 modern 100-watt incandescent light bulbs. The temperature in the arc could rise to 4,000 degrees Celsius (more than 7,000 degrees Fahrenheit), the highest temperature that man achieved until the arrival of the atomic bomb...the light it produced was incomparably stronger than anything else available at that time: candles, oil lamps and – appearing around the same time – open flame gas lights, which produced only 10 to 20 candlepower."

A moonlight tower in Detroit in the 1890s.

The heat of arc lights made them dangerous and impractical for indoor lighting, but great for towers standing high above city streets. The towers seemed brilliant, in theory--they were far brighter than anything else inventors had created, and harnessed a technology that was still in its infancy. The towers of light also seem somewhat majestic, given their lunar inspiration. This was the future arriving in the late 19th century, and it was inspired by the moon.

The dream didn't last, of course. Those majestic towers were at times rickety, crashing down in tangles of metal and heavy electrical cables. And the light they produced was at times unsettling. The Atlantic writes "Animals, for one thing, were unaccustomed to the newly extended daytime. Chickens and geese, unable to sleep in this new state of omnipresent light, began to die of exhaustion. Humans, too, found the high-slung orbs to be as disorienting as they were ethereal. As tall as the towers were, they still left shadows in their wake -- shadows tinged with sharp blue light, [author Ernest] Freeberg notes, which left pedestrians 'dazed and puzzled.' "

Direct, pointed lighting from the towers would illuminate certain parts of cities while leaving the rest drenched in darkness. And on foggy nights--or smoggy nights, in cities like Detroit which were pumping out smoke thanks to the bold new industrial era--the lights couldn't penetrate down to street level. They were eventually considered a failure and replaced with new forms of lighting. But a few survive to this day, still lighting the streets of Austin, Texas. Check out The Atlantic's story for more on the brief, curious history of moonlighting.