For most of human history, the arrival of darkness meant the end of the working day. Cities could extend their activity somewhat with candles, oil lamps, and eventually gas lighting, but nighttime remained fundamentally different from daytime.
Then, in the late nineteenth century, electricity began to change that equation.
One of the most spectacular experiments was the Moonlight Tower—a massive steel or iron tower carrying powerful electric arc lamps high above the streets. Instead of illuminating one street corner at a time, these towers attempted to illuminate entire neighborhoods from a single elevated source.
For a brief period during the 1880s and 1890s, cities across America embraced the concept. Towers appeared in Detroit, San Jose, Aurora, New Orleans, Grand Rapids, Austin and other cities.
The idea was simple: Put the brightest artificial light available as high as possible, and let it illuminate the city from above.
The engineering, however, was anything but simple.
The Idea Before the Moonlight Tower
The concept grew out of a fundamental problem with nineteenth-century street lighting. Gas lighting had transformed urban life during the first half of the nineteenth century, but gas lamps produced relatively modest amounts of light. A city needed large numbers of lamps, each requiring its own gas supply and maintenance. The result was a city of isolated pools of illumination surrounded by darkness.
Electric arc lighting offered something completely different. Arc lamps could produce enormous amounts of light compared with ordinary gas flames or the early incandescent lamps that would eventually become dominant. Engineers therefore began thinking about a different way of organizing urban illumination.
Instead of asking: “Where should we put the next streetlamp?,” they asked: “How much of the city can we illuminate from one very powerful light?”
This became known as the “high light” principle.
The higher the light source was placed, the larger the area it could potentially illuminate.
That concept would become the foundation of the Moonlight Tower.
The Technology That Made the Idea Possible
The tower concept depended on several technologies developing at nearly the same time.
The first was the carbon arc lamp. In an arc lamp, electricity jumps across a small gap between two carbon electrodes. The resulting electrical arc becomes extraordinarily hot and produces an intense white light.
The carbon electrodes gradually burn away, meaning the gap had to be continually adjusted. This made arc lighting substantially more complicated to maintain than later electric lamps.
But in the 1870s and early 1880s, that inconvenience was outweighed by one enormous advantage: brightness.
The carbon arc was among the most powerful artificial light sources available.
The second technological breakthrough was the development of practical electrical generators capable of producing the current required to operate multiple arc lamps.
Charles F. Brush and other electrical pioneers developed systems that made arc lighting commercially practical. Brush’s system was particularly important because it allowed multiple arc lamps to be operated from central generating equipment.
The third piece of the puzzle was structural engineering.
A lamp that was 20 or 30 feet above the street could illuminate only a limited area. A lamp 150 or 200 feet above the street could potentially illuminate several blocks.
Engineers therefore began building extremely tall iron structures capable of supporting lamps, electrical equipment and maintenance platforms high above the city.
The Moonlight Tower was born from the combination.
The First Towers
There is no single inventor who can accurately be credited with inventing the Moonlight Tower.
The concept developed almost simultaneously in several American cities as electrical companies experimented with ways to sell their new technology to municipalities.
One of the earliest documented tower systems appeared in Akron, Ohio, in 1881.
According to historical accounts, Akron’s city government sought proposals for a tower or mast that could demonstrate the effectiveness of electric lighting. James Bardsley, who worked as a foreman in the city’s boiler shops, submitted a design and received the contract.
The resulting tower was approximately 215 feet high.
It was essentially an enormous iron mast carrying an electric light high above the ground.
The experiment was important—but it also demonstrated one of the major engineering problems of the concept.
The Akron tower relied on supporting cables. When those cables failed, the tower collapsed.
That failure influenced subsequent tower designs.
San Jose Takes the Idea Further
The concept was dramatically developed in San Jose, California, later in 1881.
James Jerome Owen, publisher of the San Jose Mercury, became fascinated with electric lighting after seeing demonstrations in San Francisco.
Owen proposed a radical idea: rather than install conventional electric lamps throughout downtown San Jose, the city could erect a single enormous tower carrying powerful arc lights and illuminate the entire downtown area.
On May 13, 1881, Owen published an editorial advocating the idea. He described the concept as providing one enormous source of arc light so that nighttime could effectively become daytime in the downtown district.
The city approved the plan, and construction began in August.
The resulting structure was extraordinary. The San Jose Electric Light Tower rose approximately 237 feet, including its flagpole. Six carbon arc lamps were mounted near the top, producing a combined output reported at approximately 24,000 candlepower.
It stood directly over the intersection of Market and Santa Clara Streets, effectively turning one of the city’s busiest intersections into the center of an enormous outdoor lighting experiment.
Electricity came from a steam-powered generator located at a nearby planing mill. The mill used its steam engine during the day, while the generator could provide electricity for the tower at night—a clever example of early electrical infrastructure being integrated with existing industrial machinery.
When the tower was ceremonially illuminated on December 13, 1881, it became a national sensation.
Newspapers and magazines treated it as evidence that electricity was about to revolutionize urban life.
Why San Jose’s Tower Was So Important
The San Jose tower represented an important change in thinking.
Electricity was no longer merely something used inside a building.
It was becoming a municipal infrastructure technology.
The tower demonstrated that electricity could be generated at one location, transmitted to another location and converted into useful illumination on an enormous scale.
It also demonstrated the concept of centralized lighting. One generator could power multiple lamps. One elevated lighting structure could illuminate hundreds of homes and businesses.
In an era when electricity was still mysterious to much of the public, the visual effect was extraordinary. People could literally see the future hanging above their heads.
The “Several Tower” System
The next logical step was to stop thinking about a single tower.
If one tower could illuminate a portion of a city, several strategically positioned towers could theoretically illuminate an entire city.
This became known as the multiple-tower or “several tower” system.
Aurora, Illinois, provides an excellent example.
In 1881, the city contracted for a Brush electric lighting system consisting of several towers. Seven strategically positioned towers eventually carried powerful arc lamps, with the goal of illuminating much of the city rather than concentrating the light in a single downtown location.
The system first operated on November 8, 1881.
Contemporary observers were fascinated by the result. Some residents reported that the new electric light allowed them to see considerably farther down streets than they could under gas lighting. Others remarked that the light appeared more like daylight than traditional street illumination.
The Aurora system illustrates an important point: Moonlight Towers were not originally designed simply because they looked impressive. They were an economic and engineering strategy. A city could potentially illuminate a much larger area with a relatively small number of high-powered lights than it could with hundreds of conventional street lamps.
Detroit Builds a Citywide Experiment
Perhaps the most ambitious early experiment occurred in Detroit, Michigan.
In 1884, Detroit contracted with the Brush Electric Light Company to construct a system of 122 electric light towers.
The towers were approximately 150 feet tall, with groups of arc lamps mounted at their tops. The system was intended to illuminate roughly 21 square miles of the city. This was no small demonstration. Detroit was attempting to use electricity to create a citywide artificial “daylight” system.
The towers were positioned throughout the city so that their light overlapped. Maintenance crews had to climb the towers and service the lamps, and the system required regular attention because carbon arc electrodes were consumed during operation.
The towers became such a recognizable feature of Detroit that they appeared in photographs, newspapers and popular culture. One Detroit newspaper even published poetry imagining that the artificial moonlight had made the actual moon jealous.
The Problem With Light From Above
The Moonlight Tower concept had a serious weakness. Light does not necessarily become better simply because it becomes brighter.
The towers could illuminate huge areas, but they did not provide the controlled, uniform illumination that modern street lighting seeks.
A tower could create bright areas underneath and near the tower while leaving darker areas farther away. Trees and buildings could block the light. Pedestrians could also be standing in deep shadows even though the general area appeared brightly illuminated.
This became increasingly important as cities became denser.
The growth of taller buildings made it harder for a single elevated lamp to illuminate streets effectively.
The tower system was therefore an ingenious solution to a problem that was itself rapidly changing.
The Rise of the Incandescent Lamp
The Moonlight Tower’s greatest technological competitor eventually became the incandescent lamp.
Early incandescent lamps were initially far less powerful than carbon arcs. But they had a major advantage: They were easier to operate and maintain.
An incandescent lamp did not require an electrical arc to be continuously maintained between two electrodes.
As electric generating stations and distribution networks expanded, cities could install large numbers of relatively inexpensive electric lamps.
Instead of putting enormous amounts of light in a few locations, engineers could distribute smaller amounts of light exactly where they were needed.
This was the beginning of the end for the Moonlight Tower.
Austin Enters the Story
Austin adopted the tower concept later than Detroit and San Jose, but its system became the most famous surviving example.
In the early 1890s, Austin was developing a municipal electric utility based around the construction of a hydroelectric dam on the Colorado River.
The Austin Dam, completed in 1893, provided the generating capacity that city leaders hoped would power a new electric system.
In 1894–1895, the city installed 31 Moonlight Towers manufactured by the Fort Wayne Electric Company of Indiana. The towers were approximately 165 feet tall, constructed as vertical truss structures and stabilized with guy wires.
By May 1895, Austin’s towers were operating as part of the city’s first electric street-lighting system. The Austin system was therefore not merely a street-lighting project. It was a highly visible demonstration of the city’s new municipal electric utility.
Were Austin’s Towers Really From Detroit?
This is where the history becomes particularly interesting.
For decades, the popular story has been that Austin purchased 31 surplus Detroit towers when Detroit began abandoning its system. That story has some historical basis, and Austin’s towers were certainly associated with the same technological lineage. However, the evidence is more complicated than the traditional story suggests.
The Texas State Historical Association identifies the Austin towers as having been fabricated by the Fort Wayne Electric Company and shipped to Austin in pieces, rather than simply being dismantled Detroit towers transported south.
The confusion probably comes from the fact that Detroit had already demonstrated the system on a huge scale and that Fort Wayne’s towers represented an evolution of designs used in earlier systems.
So rather than imagining Austin buying 31 rusty towers directly from Detroit, it is more accurate to see Austin as purchasing a mature commercial tower-lighting system from an established electrical manufacturer.
Why Austin Kept Them
Most cities eventually removed their towers. Austin didn’t.
Part of the reason was practical: the towers continued to function. But history and circumstance also played a role. Austin’s relatively low-rise development meant that the towers remained useful for illuminating neighborhoods.
They also became part of the city’s identity. By the twentieth century, the towers had become historical artifacts even while they were still performing their original function. That makes Austin’s system particularly unusual.
Most historic lighting technology survives in museums.
Austin’s Moonlight Towers survived while still being used as lights.
Austin’s Living Lighting Museum: The Changing Lamps
Few surviving lighting installations provide such a clear physical record of the evolution of electric light like the Moonlight Towers of Austin.
Carbon Arc
The original towers used carbon arc lamps. These were exceptionally bright but maintenance-intensive. Carbon electrodes gradually burned away and required adjustment and replacement. The early towers therefore needed crews to keep the lamps operating properly.
Incandescent
In the 1920s, Austin replaced the carbon arcs with incandescent lamps. The new lamps were easier to maintain but fundamentally changed the lighting characteristics. The towers were no longer dependent upon the brilliant electrical arc that had made them famous.
Mercury Vapor
In 1936, Austin converted the towers to mercury-vapor lamps. Mercury vapor offered substantially longer lamp life and better efficiency than incandescent sources, while producing the distinctive cool, blue-green appearance that became associated with Austin’s towers.
LED
The technology has now entered another chapter. The surviving Austin towers have been modernized with LED lighting, preserving the towers’ function while dramatically reducing the energy and maintenance requirements associated with their older lamp systems. The remarkable part is that the structure has remained while the light source has changed four times.
The Towers Change the Meaning of Night
That may ultimately be the most important legacy of the Moonlight Tower. The technology was eventually made obsolete, but the concept it represented never disappeared.
Modern cities continue to pursue the same fundamental objective with:
- roadway lighting
- high-mast highway lighting
- sports lighting
- parking-lot lighting
- area floodlights
- airport lighting
- industrial site lighting
- architectural illumination
Modern high-mast lighting is, in many respects, a descendant of the same basic idea: put powerful lighting high above an area and illuminate a large space from a small number of locations.
The difference is that modern lighting engineers have vastly better optical control.
Instead of allowing light to simply spill outward from a powerful arc lamp, modern luminaires use reflectors, lenses, and precise beam distributions to put light where it is needed and minimize wasted illumination.
The Moonlight Tower had the concept, but modern lighting has the optics.
What Happened to the Other Towers?
As electrical distribution networks expanded and incandescent, fluorescent, high-intensity-discharge, and eventually LED technologies became available, most cities abandoned their tower systems.
Detroit’s enormous network disappeared.
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San Jose’s famous tower collapsed during a storm on December 3, 1915. Today, a half-scale replica stands at History Park in San Jose.
Other cities dismantled their towers as conventional streetlighting became more economical and practical.
Austin is the remarkable exception.
Of the original 31 Austin towers, 17 remained by the early 1990s, and a major restoration program subsequently preserved them. The towers received historic recognition as Texas landmarks in 1970 and were placed on the National Register of Historic Places in 1976.
The Last Moonlight Towers
Today, Austin’s surviving towers are more than historic objects. They are functioning pieces of electrical history.
They still stand approximately 165 feet above the streets, occupying many of the same locations where they were installed in the nineteenth century.
The structures have been restored, the electrical systems have evolved, and the lamps have changed dramatically. But the fundamental idea remains exactly the same: One elevated source of artificial light illuminating a large area below.
That makes the Austin Moonlight Towers extraordinary survivors.
From Arc Light to LED
The story of the Moonlight Tower is therefore not simply the story of an obsolete lighting system. It is a story about the birth of modern outdoor lighting.
The towers appeared at a moment when engineers were discovering that electricity could do more than power machines.
It could reshape the city. It could extend working hours. It could change patterns of transportation. It could affect public safety. It could alter the appearance of streets and buildings. And, perhaps most importantly, it could change humanity’s relationship with darkness.
For a brief period in the 1880s and 1890s, engineers tried to put the sun—or at least something resembling it—above the city.
The experiment ultimately failed as a practical lighting system. But in Austin, the experiment never completely ended.
The lamps have changed.
The generators have changed.
The electrical distribution system has changed.
The technology has changed from carbon arc to incandescent to mercury vapor and finally to LED.
But the towers remain.
And every night, more than a century after electric lighting first began transforming American cities, Austin’s surviving Moonlight Towers continue to perform the same remarkable experiment their designers envisioned in the nineteenth century: turning night into something humans can engineer.
Featured Image Courtesy of Amusing Planet.
