In 1879, an inventor named Thomas Edison finally got his big idea to work. It was a lamp powered by electricity. The principle remains familiar today: a current passed through a filament enclosed in a glass bulb causes the filament to become incandescent.

It took about ten years to get from prototype to commercial product, and this was only after several predecessors had failed to develop a product of sufficient reliability for sale to the public. The problem was thermal cycling of the filament, leading to failure in fatigue once the bulb had been switched on and off a few times.

Lightbulbs are still like that; incandescent ones at least. The original carbon filaments have been replaced by tungsten, and a cage of support wires bears the weight (at the expense of conducting away heat and hence reducing efficiency). In spite of these elaborations, a typical bulb lasts about a thousand hours, and it's an exceptionally long-lived one that as much as doubles that lifetime.

All of this makes a lightbulb in a Californian fire station rather unusual.

The Livermore Light

Less than 25 years after 'the Wizard of Menlo Park' secured his patent, the Shelby Electric Company made a carbon-filament lamp with a hand-blown bulb. To be more accurate, they made thousands, but one in particular found its way to the hose-cart house of the fire department of Livermore, California. It was first switched on in the summer of 1901. The same bulb is still working more than a hundred years later¹. The claim of World's Oldest Lightbulb has been verified by the Guinness Book of Records, and is said to be ratified by newspaper records and a technical audit by General Electric.

The 'Livermore Light' has burned continuously for most of its life, putting out a steady four watts or thereabouts. It originally served as a nightlight, illuminating the area where the fire-tenders were housed, but has long since progressed to the status of revered curiosity. It has been moved without mishap a couple of times over the years, most recently in 1976 to the current site of the station at 4550 East Avenue.

The bulb's hundredth birthday was celebrated on 8 June, 2001 with a community barbecue. Three bands provided live music: one contemporary, another playing 1950s tunes and the third performing in the style of the first years of the 20th Century. The Livermore Light has its own website and is open to visits by the public.

Individual specimens of modern low-energy bulbs have a chance of surpassing the Livermore Light, given time. Several types are inherently longer-lived than incandescent bulbs, because they generate much less severe stresses in their components. Having said that, many buildings, required to house them, last less than a hundred years, and so perhaps the record will never be broken. All of the closest known rivals seem to have gone 'pop' in recent years, with other American examples from 1908 and 1912 both expiring around the turn of the millennium: as did the oldest British contender, which dimmed for the last time in January, 2001 in the washroom of an Ipswich electrical shop where it had operated since 1930.

The Livermore-Pleasanton Fire Department has no plans to replace their celebrated lightbulb. Although its usefulness is minimal, it's now too big an attraction to contemplate disposal. When it does eventually succumb, it certainly won't be thrown away either. Ripley's museum is first in line to receive and preserve the corporeal remains of the longest-lived lightbulb in history.