The light bulb that hasn't gone out since 1901

In Fire Station No. 6 in Livermore, California, hangs a small, hand-blown bulb with a carbon filament. It was switched on in 1901, before commercial radio or assembly-line cars existed, and — apart from power cuts and a couple of moves — it hasn't gone out since. During the 1976 move it travelled for twenty-two minutes inside a box, escorted by a patrol car, and was lit again on arrival.

Nobody quite knows why it endures. It glows faintly, at about four watts, an ember-orange gleam; perhaps that is precisely what has saved it — never being switched off and on, never suffering surges. Its maker, the Shelby Electric Company, closed over a century ago: the bulb has outlived its own company.

Since 2001 a webcam has streamed it live, and here comes the detail worth telling at dinner: the camera has broken down several times and had to be replaced. The bulb has watched its own guardians die. The firefighters have clear orders: nobody touches that socket.