THIS lightbulb has ensured no-one is left in the dark — for 110 years.

03aecac1b59f1484288413bdc1e99899.PNGThe bulb has been declared the oldest known working light by the Guinness Books of World Records. It has held pride of place in a fire station, in Livermore, northern California, since 1901. With the exception of a brief period in 1903, a week in 1937, and some power outages between then and 1976, the bulb has shone continuously.  The light has sparked debate between baffled scientists who cannot understand how it has continued to glow.

Lynn Owens, the chairman of the town's lightbulb centennial committee, said: "Nobody knows how it's possible. It is a 60 watt bulb and it's only turned on for about four watts but nobody knows why it keeps burning.  "We've had scientists from all over the country looking at this lightbulb. Of course nobody has ever been able to touch it."

The bulb has become a hit with tourists from across the world who have been drawn towards the incessant light.