This online exhibition explores electric lighting within the home. It briefly describes life before electricity, early developments in lighting and how the benefits of electricity were promoted.
All the lights before electricity relied on a flame, which caused problems such as bad smells, uncomfortable heat, dirt or the taking of oxygen from the air. Electricity on the other hand opened up new opportunities.
A major practical problem with the development of electric lighting was the need to find a suitable source of electricity that was not expensive. Michael Faraday established the principle of electromagnetic induction in 1831 which led eventually to electric generators that could produce electricity in large quantities at a modest cost. On this discovery scientists were able to experiment with electricity and lighting.
The first electric lights were Arc Lamps. The principle is that two pieces of carbon, connected to an electricity supply, are touched together and then pulled apart. A spark or 'arc' is drawn across the gap and a white hot heat is produced. For more details on the development and usage please see our Arc lamp online exhibition.
Illustrations from Crompton & Co. Electric Light Engineers showing the variety of enclosed arc lamps and half watt lanterns available.
The Arc Lamp produced a very bright light so was better suited for illuminating large areas such as railway stations and street lighting. For domestic use, a smaller light was required. The dazzling light of the arc needed to be 'sub-divided' into smaller lights. This was achieved with the development of incandescent filament lamps.
In an incandescent filament lamp the heated wire was first made of carbon and heated until white hot ('incandescent') by passing an electric current through it. Early experiments show that it was not a simple procedure as a filament material that could be heated to white hot temperatures and then cooled without breaking was required. A means of sealing the connections in a glass bulb without the heat cracking it and a vacuum pump to remove sufficient air to prevent oxidation also needed to be found.
Experiments with metal filaments demonstrated that they could run at a higher temperature than carbon. Platinum was used in early tests but was far too expensive for general use. Metals with very high melting points were tried and tungsten was found to be the most successful with the highest melting point that any other metal.
The filament lamp was not invented by one person, improvements and experiments were carried out by many. For instance, Joseph Swan and Thomas Edison's joint efforts amalgamated in the Edison and Swan United Electric Light Company Ltd in 1883.
It was not until the late 1870s that a practical lamp was created. By the end of the nineteenth century electric lighting usually meant arc lamps for outdoor use and the filament lamp the preferred light for indoors.
This photograph shows different light fittings in an office in the nineteenth century.