Inside a fire station in Livermore, California, a single light bulb has been glowing for more than a century.
It was first switched on in 1901. It has survived renovations, relocations, a faulty power supply, and two world wars. It has outlasted presidents, industries, and entire eras of technology.
And it was made in Shelby, Ohio.
Known as the Centennial Light, the bulb is recognized by Guinness World Records as the oldest known operating light bulb in the world. While it now gives off only a faint glow equivalent to about four watts, roughly the brightness of a nightlight, it has been burning almost continuously for 125 years.
Long before Silicon Valley startups and smart homes, a small Ohio factory built a bulb that simply refused to quit.
Born In Shelby
The Centennial Light was manufactured in the late 1890s by the Shelby Electric Company in Shelby, Ohio. At the time, electric lighting was still evolving rapidly, and competition among lamp makers was fierce.
The Shelby Electric Company was not a minor operation. Organized with $100,000 in capital stock, the company quickly became one of the most ambitious electric lamp manufacturers in the country. By 1902, the plant was capable of producing 10,000 finished lamps per day. Local newspapers proudly noted that the company stood outside the so-called electrical trust, positioning itself as an aggressive competitor in a fast-growing industry.
The technical force behind the Shelby lamp was Adolphe A. Chaillet, a French engineer credited with developing an improved carbon filament design. Company literature from the 1890s claimed the Shelby lamp delivered 20 percent greater efficiency and a 30 percent longer life than other lamps on the market. Tests at the time reportedly showed the Shelby bulb outperforming competitors in forced life trials.
In short, this was not an accidental success. The company was intentionally building durable, high quality lamps at a time when electric lighting still felt like the future.
One of those hand blown carbon filament bulbs eventually made its way west.
A Donation That Changed History
In 1901, the bulb was donated to the Livermore-Pleasanton Fire Department in California by Dennis Bernal, owner of the Livermore Power and Water Company. According to local accounts, Bernal gifted the bulb to the fire station when he sold his company.
It was installed in a hose cart house on L Street and turned on.
It has been glowing ever since.
Over the decades, the bulb moved at least four times as the fire department relocated. During a 1937 renovation, it was turned off for about a week. In 1976, when the department moved into Fire Station No. 6, officials refused to risk unscrewing it from its socket. Instead, they cut the cord and transported the bulb under escort in a specially designed box. The power interruption during that move lasted just 22 minutes.
Today, the bulb runs on an uninterruptible power supply. In 2013, viewers watching a dedicated webcam thought they had witnessed its final flicker. After nearly ten hours of darkness, electricians determined the problem was a faulty power supply. The bulb itself was fine.
It returned to its steady glow.
Why Has It Lasted So Long?
Several factors help explain the Centennial Light’s longevity.
First, it was built differently. The bulb uses a thick carbon filament rather than the thinner tungsten filaments common in most modern bulbs. The components were handmade, with high-quality brass and glass. It was originally a 60-watt bulb, but over time its output has dimmed to about four watts.
Second, it is almost never turned off. Switching a bulb on and off causes repeated heating and cooling cycles that stress the filament. By staying on continuously, the Centennial Light has avoided much of that wear.
There is also the matter of philosophy. The Shelby Electric Company was operating in an era when durability was a selling point. The company’s promotional materials emphasized efficiency, strength, and longer life. In the late 1800s, proving that your lamp could outlast a competitor was powerful marketing.
More than a century later, one of those lamps is still making the case.
A World Record With Ohio Roots
The Centennial Light was officially recognized by Guinness World Records in 1972 as the most durable light. It has been featured by major news networks, highlighted in documentaries, and even appeared on MythBusters. It has its own website and a loyal following of curious viewers who check in on its steady glow.
Every few months, according to the Livermore fire chief, another wave of media attention brings visitors to see it in person. Then things quiet down again.
Through all of it, the bulb remains in the care of the Livermore-Pleasanton Fire Department. When it finally burns out, there are no firm plans for what happens next, though Ripley’s Believe It or Not has expressed interest in acquiring it.
Until then, it continues to glow. Not too bad for something that was never supposed to make history.
