Light Bulb's Glow Spans 9 Decades

SAN FRANCISCO - A light bulb that lasts at least 10 years? Big deal. How about one that's been burning since 1901!

Intersource Technologies of Sunnyvale created a splash this month when it unveiled its new E-lamp during a meeting of the Edison Electric Institute, an association of utility companies. Intersource said the bulb lasts from 10 to 14 years.

The people at the Livermore Fire Department's Station One were not all that impressed. After all, a little bulb that has been burning not-quite-brightly since the turn of the century put the firehouse in the record books.

The glow of its reputation attracts tourists from around the world.

"We keep a visitors book for them to sign," said Helen Vien, a fire department clerk. "A good many of them stop by just to look at the bulb, which is real dim and hangs high up and out of the way on an old-fashioned cord."

The Guinness Book of Records and Ripley's Believe It or Not both list it as the oldest and longest-burning light bulb in the world.

With the exceptions of power failures and three times for moving it to another station, the bulb has been on since it was donated to the fire department in 1901 by Dennis Bernal, owner of the Livermore Power and Water Company.

The incandescent bulb was invented by Thomas Edison in 1879.

General Electric Co. determined that the bulb was manufactured by the Shelby Electric Company and was hand-blown with a carbide filament.

G.E. says there is no great mystery to the bulb's longevity. The lower the wattage, the longer the filaments last. The bulb puts out about as much light as the coils inside a toaster.

Barbara Fairhurst, spokeswoman for Intersource Technologies, said she's familiar with the bulb. "I think it's fascinating," she said.

She agreed with GE's assessment and pointed out that the carbide filament also helps.

The real secret, she says, is that the light is always on. "Turning a bulb off and on is what wears it down."