Joseph Swan returns to consider the problem…

Joseph Swan returns to consider the problem of the light bulb with the aid of a better vacuum and a carbonized thread as a filament in 1875.

The most significant feature of Swan's improved lamp is that there is little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire.

However, his filament has low resistance, thus needing heavy copper wires to supply it.

Joseph Wilson Swan was born in 1828 at Pallion Hall in Bishopwearmouth (now part of Sunderland, Tyne and Wear).

His parents were John Swan and Isabella Cameron.

He had served an apprenticeship under a pharmacist there, and had later become a partner in Mawson's, a firm of manufacturing chemists in Newcastle upon Tyne. (This company will exist as Mawson, Swan and Morgan until 1973, formerly located on Grey Street in Newcastle upon Tyne near Grey's Monument.

The premises are now owned by the Swedish fashion retailer H&M and can be identified by a line of Victorian-style electric street lamps in front of the store on Grey Street.)

Swan lives at Underhill, a large house on Kells Lane North, Low Fell, Gateshead, where he conducts most of his experiments in the large conservatory. (The house will later be converted into a private fee-paying, grant-aided, co-educational grammar school named Beaconsfield School. Here, students could still find examples of Swan's original electrical fittings.)

In 1864, Swan patents the carbon process for printing photographs in permanent pigment.

When working with wet photographic plates, Swan had noticed that heat increased the sensitivity of the silver bromide emulsion.

By 1871, he had devised a method of using dry plates and substituting nitro-cellulose plastic for glass plates, thus initiating the age of convenience in photography.

Eight years later, he patents bromide paper, developments of which are still used for black-and-white photographic prints.

In 1850, Swan had begun working on a light bulb using carbonized paper filaments in an evacuated glass bulb.

By 1860, he had been able to demonstrate a working device.

However, the lack of a good vacuum and an adequate electric source had resulted in an inefficient bulb with a short lifetime.