At 119-year-old (as of May 2021), the Centennial Light is the world’s longest-lasting light bulb. Burning since June of 1901, it is currently located inside Fire Station #6 at 4550 East Avenue, Livermore, California, and maintained by the Livermore-Pleasanton Fire Department.
The bulb has been officially recognized by The Guinness Book of World Records, Ripley’s Believe It or Not!, and General Electric as the world’s longest-burning light bulb. (It’s gone out during a couple of power outages, and it was briefly turned off when it was moved in 1903, for a week in 1937, and in 1976 when it was moved again)
If you want to see or learn more about the Centennial Light and it’s interesting history, visit www.centennialbulb.org. A webcam keeps an eye on the bulb 24/7. In fact, a photo is uploaded to http://www.centennialbulb.org/cam.htm every 30 seconds.
Manufacturer: Shelby Electric Company in Shelby, Ohio (est. 1896, out of business 1912).
Manufacture date: c. 1898.
Designer: French electrical engineer Adolphe A. Chaillet (b. Nov 1867, d. ~1914).
Filament: Carbon, made by a “secret process” that is still unknown today. The filament forms a loop inside the bulb that, from below, looks like the word “no” written in cursive.
Wattage: The bulb is thought to be a 60-watt model (actual figure unknown), but it currently burns at about four watts.