The rare specimen sold for £7500 (plus 25% buyer’s premium) at Bonhams' September 19 sale titled Instruments of Science and Technology.
Born in Pallion, Sunderland, Swan created his first prototype incandescent light bulb around 1860, later using carbonised thread and improved vacuum pumps to improve the lifespan and quality of the light it emitted.
He first publicly demonstrating this longer-lasting product during a popular 1878-79 lecture series at the Newcastle upon Tyne Chemical Society before forming the Swan Electric Light Company Ltd to manufacture bulbs for both private and commercial use in 1880. Some 1200 of them were installed at the Savoy Theatre in London - the first public building to be lit entirely by electricity.
Bonhams' rare survivor, with a carbon rod filament, dates from c.1877. Measuring 5in (13cm) across and mounted horizontally in a mahogany case, a brass plaque reads: The First Incandescent Electric Lamp. This was made in 1877 (circa) by Sir (then Mr) Joseph Wilson Swan. Previously exhibited at The Royal Society, it had been estimated at £4000-6000.
