Fifteen Eighty Four

The incandescent lamps was the killer application of the electrification. Just a couple of years ago we decided to say goodbye to this lighting workhorse. A first assumed successor – the CFL – was not embraced by consumers. Nevertheless it pioneered the transition to energy-efficient lighting. And now the LED lamp takes over.

This article is the final instalment in a series of five on product evolution. They illustrate that technological evolution can explain ‘the origin of products’, although one of a different nature than we know from biological species.

For thousands of years people used oil lamps and candles to illuminate their homes during dark hours. Both did not produce a lot of light and were inconvenient in use, as they require their fuel to be replenished. Besides, open fire is notoriously dangerous. Then at the start of the 19^th century gas lamps fuelled by coal-gas distributed by a network of pipes became an innovative solution to illuminate the streets of in European cities. Gas lamps became a huge success but also remained dangerous because of their open fire and toxic fumes. Many theatres illuminated by gas lamp burned down killing many. The world longed for a safer type of light!

Electric light

Progress is sometimes due to bizarre experiments. That was surely the case with the Italian Luigi Galvani who once touched the leg of a dismembered dead frog with a metal object. The frog leg kicked as if alive. This drew the attention to the phenomenon of electricity. Alessandro Volta, also Italian, continued experiments to understand the matter and developed the first battery. This provided the first practical source of electricity, which was then used by David Humphrey for more electrifying experiments. He took huge amounts of batteries, and a platinum strip and conducted an electric current through it until it illuminated light. And there it was, electric light by incandescence! A second experiment that produced light was by means of an arc between to carbon rods. The electric arc made it to a first commercialised version of electric light, the arc lamp. However, it was not ideal. The lamp produced an intense light that could not be dimmed. Besides, it still produced unpleasant fumes, and the rods needed to be replaced regularly.

Incandescent

Decades of pioneering experiments finally delivered incandescent lamps. In 1879 two different inventors on both sides of the North Atlantic claimed a patent for a first incandescent lamp using thin carbon wires that light up glowing when sufficient electricity is conducted through it. These were Joseph Swan in the UK and Thomas Alva Edison in the USA. And they were not the first to experiment with these lamps. No fewer than 19 inventors claimed patents on incandescent lamps before Swan and Edison.  However, all these pioneering predecessors failed to commercialise their inventions.

The invention of the incandescent lamp was the first large scale application of electricity. Obviously this requires power stations to generate and networks to distribute the electricity. In the early days, dual current (DC) dominated and only short distances could be covered between power station and point of use. There was no voltage standard in networks yet. Only once networks started using alternating current (AC) they could cover larger distances and the need arose to use same voltages in coupled AC networks. Since these days the world became divided in 110 Volt and 220 Volt networks, something that has not changed since.

The incandescent lamp became a huge success. First types that used carbon filaments could only be used for about 40 hours. This implied that one needed to replace lamps quite soon. And so a huge industry arose for making incandescent lamps. These new industrial companies started to employ inventors that experimented with many types of materials and constructions aiming to increase the lamp life. Once it was clear how one could process tungsten into ductile filaments, the incandescent lamp improved lifespan towards thousand hours. Still it required regular replacement, commonly once a year, and therefor the screw base interface was designed that became a standard we still use today. The lamp that evolved in this way became known as the general lighting solution or GLS and remained the preferred type of electric light for consumers for almost a century.

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