Alan Archibald Campbell-Swinton

Alan Archibald Campbell-Swinton

Alan Archibald Campbell-Swinton, FRS (1863, Kimmerghame House, Berwickshire – 1930, London) was a Scottish consulting electrical engineer. He described an electronic method of producing television in a 1908 letter to Nature.

Biography

Campbell-Swinton was educated at Cargilfield Trinity School and Fettes College (1878–1881).^[1]

He was one of the first to explore the medical applications of radiography, opening the first radiographic laboratory in the United Kingdom in 1896. He was elected a Fellow of the Royal Society in 1915.

Campbell-Swinton wrote a letter in response to an article in the 4 June 1908 issue of Nature by Shelford Bidwell entitled "Telegraphic Photography and Electric Vision". Even as early as 1908, it was recognized that "The final, insurmountable problems with any form of mechanical scanning were the limited number of scans per second, which produced a flickering image, and the relatively large size of each hole in the disk, which resulted in poor resolution".

Campbell-Swinton's letter ^[2][3] was published in the 18 June 1908 issue of Nature. The name of the article is "Distant Electric Vision". He wrote: "This part of the problem of obtaining distant electric vision can probably be solved by the employment of two beams of cathode rays (one at the transmitting and one at the receiving station) synchronously deflected by the varying fields of two electromagnets placed at right angles to one another and energised by two alternating electric currents of widely different frequencies, so that the moving extremities of the two beams are caused to sweep simultaneously over the whole of the required surface within the one-tenth of a second necessary to take advantage of visual persistence. Indeed, so far as the receiving apparatus is concerned, the moving cathode beam has only to be arranged to impinge on a suitably sensitive fluorescent screen, and given suitable variations in its intensity, to obtain the desired result."

He gave a speech in London in 1911 where he described in great detail how distant electric vision could be achieved. This was to be done by using cathode ray tubes (CRTs) at both the transmitting and receiving ends.^[4] This was the first iteration of the electronic television which is still in use today. When Swinton gave his speech others had already been experimenting with the use of cathode ray tubes as a receiver, but the use of the technology as a transmitter was unheard of.

In 1914 he once again described his system in his presidential address to the Roentgen Ray Society and in 1921 a book was published describing it in some detail.^[5] He himself described his system seven years later in the June 1928 issue of Modern Wireless, "Television by Cathode Rays".

"Surely it would be better policy if those who can afford the time and money would abandon mechanical devices and expend their labours in what appears likely to prove the ultimately more promising method in which the only moving parts are imponderable electrons."

By this time, although electromechanical televisions were still being introduced, inventors Philo Farnsworth, Vladimir Zworykin and Hungarian Kálmán Tihanyi were already working separately on versions of all-electronic transmitting tubes.

See also

• Clan Swinton

References

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