Let there be light.
A few years after Sir Joseph Swan invented light bulbs he came up with the idea of fairy lights to illuminate London's Savoy Theatre--and now they brighten up all our lives at Christmas.
Sir Joseph Swan is one of the many people credited with the invention of the incandescent electric light bulb, and his house in Gateshead was the first in the world to be lit by light bulbs. It was Swan who oversaw the fitting of his good friend Sir William Armstrong's Cragside house in Northumberland with electric light bulbs.
Swan was born in 1828 near Sunderland, and trained as a chemist. It was his work in the photographic division of John Mawson's company that led him to start thinking about the use of carbon in incandescent lighting (he had previously successfully invented a type of 'carbon process' that allowed the printing of photographs without fading).
At the time, many inventors were puzzling over the issue of how to find a way of making "a scheme of electric lighting capable of giving small units of light". Swan deduced that the issue could be solved by a lamp that worked not on the well-used arc principle, but by the use of "incandescence in vacuo of a thin continuous carbon conductor of high specific resistance".
It took Swan some years to work out how to create the perfect vacuum, and to source materials cheap enough to make it a viable domestic invention. But by 1878 he had cracked it, and gave a demonstration of his incandescent carbon lamp at a meeting of the Newcastle upon Tyne Chemical Society--and then many subsequent lectures across the country, including one at the Literary and Philosophical society of Newcastle, where more than 700 gathered to see his invention. He was elected a member of the Institution of Mechanical Engineers in 1884--with his proposal written by William Armstrong: "In electricity the details of the manufacturing of the incandescent lecture lamp, Mr Swan has applied knowledge and invention ...".
Illuminated Christmas trees became popular during the late 18th century--before the advent of incandescent lights, these were often lit with candles resting on the branches (although this obviously posed a series of safety hazards!). String-like small bulbs that we would know as fairy lights came as a result of Swan and others making bulbs that could work as smaller units.
The earliest example of this is perhaps in 1881, when the Savoy Theatre in London became the first building to be lit by a type of what we would now term 'fairy light' incandescent electric light bulbs. These were Swan's design, and were installed to great acclaim--not only for safety but also the way that you could change the level of light, and the great illumination they threw on the costumes and staging.
These days, fairy lights and garlands of lights are everywhere at Christmas, although technology has moved on and rather than being incandescent light bulbs many are now LEDs.
Previous strings of lights suffered from the problem of being on one single circuit, meaning that when one light bulb went out all the bulbs went out. Now the strips of lights come equipped with shunts that can bypass the faulty light and keep the rest glowing.
By IMechE assistant archivist Sarah Broadhurst