Some inventors understand a scientific phenomenon and set about inventing a technological device to exploit the phenomenon.
The invention of the laser grew from the interest of two researchers in studying the structure and characteristics of a variety of molecules. During the Second World War, Charles H. Townes worked on developing radar navigation bombing systems. After the war he had the idea of modifying the radar techniques and using microwaves to study molecular structure. Subsequently he and Arthur L. Schawlow collaborated at Bell Labs in the USA on using the shorter wavelengths of infrared and optical light to develop an even more powerful tool – the laser (short for light amplification by stimulated emission of radiation). They were granted a patent in 1960. However they had no thoughts about any applications of their invention other than its use in their scientific research. Schawlow recalled:
We thought it might have some communications and scientific uses, but we had no application in mind. If we had, it might have hampered us and not worked out as well.
(Bell Labs, 1998)
It was left to others to devise ways of exploiting this invention in a commercial product. Although initially perceived by some as a weapon (a death ray), one of the first practical applications was in medicine for eye surgery. Lasers have gone on to have widespread use in industry for cutting and welding, in commerce for bar code readers, at home for entertainment (CD players, DVD players), in data storage and retrieval in computers, and so on (Figure 23). The world market for laser technology is now over $100 billion a year.
Inventions can arise from the technical curiosity of creative individuals rather than to meet a clear need. There are many examples, particularly in the past but still occasionally nowadays, of so-called talented tinkerers. Read Box 2 for an account of what talented tinkering can produce.
Christopher Cockerell was an electrical engineer who left the Marconi company to become a boat builder in Norfolk. He developed an interest in increasing boat speed by reducing friction between the hull and the water. He had the idea of supporting a craft on a low-pressure cushion of air contained within a high-pressure curtain of air (Figure 24). He built a mock-up to test his idea using a cat food tin inside a coffee tin connected to a vacuum cleaner reversed to blow, all mounted above a set of kitchen scales to measure the pressure exerted (Figure 25). It was three times the pressure of the blower without the tins and confirmed his theory. There had been previous attempts to build a vehicle that floated on air but Cockerell was the first to devise a way of containing the air cushion. Next he constructed a radio-controlled balsa wood model of his hovercraft to prove the hover principle would work in practice (Figure 26).
Cockerell applied for a patent in 1955. The Patent Office didn't know whether to classify it as a boat or a plane. The Ministry of Supply was similarly confused when Cockerell demonstrated his model but it immediately classified the invention as secret. It was only after Cockerell discovered the Swiss were working on a similar device that the ministry agreed it could be declassified and commercialised.
Having persuaded the National Research Development Corporation to back the hovercraft, the first full-size manned prototype SR-N1 was built by Saunders Roe in 1959 and crossed the English Channel in July of that year (Figure 27). It soon became apparent that the peripheral jet on the SR-N1 didn't provide enough lift to make it a practical form of transport. Cockerell devised and patented a flexible skirt to retain the air cushion. A series of experimental hovercraft designs for both civil and military applications followed the SR-N1. In 1962 the first passenger-carrying scheduled service started up across the estuary of the river Dee in north Wales and cross-channel services began in 1966 (Figure 28).
Although there are still commercial and military hovercraft in operation (Figure 29), high development costs, technical problems and cheaper competing technologies have meant they did not go on to become widely used. Rather they are used in specific situations where their ability to cross varied surfaces inaccessible to conventional vehicles gives them an advantage.
Cockerell resigned from Hovercraft Development Ltd after a dispute and the UK government persuaded him to sell his patent for £150 000 in 1971. He continued to work as an inventor, including designing a system of rafts to generate electricity from waves, but never really profited from his inventions. He had devised 36 inventions worth millions of pounds for Marconi and was paid £10 for each one. The money he received for his hovercraft patent didn't cover his development costs. Unsurprisingly he remained bitter at what is characterised as the UK's repeated failure to capitalise on the inventive ideas of creative individuals.
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