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Credits: An excerpt from "Watching TV: Opening the Doors of Reception" by Liss Jeffrey, Acting Director, MZTV Museum. Technical research by Gary Borton, Consulting Curator, and Iain Baird, Researcher, MZTV Museum.
"Mechanical TV: Pioneering Experiments"Mechanical TV: The Pioneers
One of the earliest proposals for a mechanical television
system was put forward by German researcher Paul Nipkow in
1883. When he developed patent No. 30,105, he was an
unknown twenty-three-year-old student living in Berlin. It
proved to be the basis for most early television schemes
in the world, although he never built the apparatus.
In Nipkow's patent, which he called an 'electric
telescope,' a disc was punched with holes in a spiral near
the outer edge. When the disc revolved, each hole
vertically scanned a line of the image, allowing
variations in light to reach a selenium cell. As one hole
swept over a segment of the picture, the next in sequence
tackled the portion next to it, until the complete subject
had been scanned.
The selenium cell transferred the light variations to
an electronic signal. Pictures were reconstituted at the
receiver by a similar disc which was synchronized with the
One of the better known experimenters with mechanical
television was Charles Francis Jenkins, a prolific
American inventor. In May 1920, at the Toronto meeting of
the Society of Motion Picture Engineers, Jenkins
introduced his "prismatic rings" as a device to replace
the shutter on a film projector. This invention laid the
foundation for his first radiovision broadcast.
He claimed to have transmitted the earliest moving
silhouette images on June 14, 1923, but his first public
demonstration of these did not take place until June of
Jenkins Laboratories constructed a radiovision
transmitter, W3XK, in Washington D.C. The short-wave
station began transmitting radiomovies across the Eastern
U.S. on a regular basis by July 2, 1928. Jenkins wrote in
1929: "This gave the amateur action-pictures to 'fish'
for; and during August following a hundred or more had
finished their receivers and were dependably getting our
broadcast pictures, and reporting thereon, to our great
It was in this way that Jenkins actively promoted
enthusiasm and experimentation in the short-wave radio
community, and the U.S. experienced its first television
boom, with an estimated 20,000 lookers-in.
John Logie Baird, a Scottish engineer and entrepreneur,
achieved his first transmissions of simple face shapes in
1924 using mechanical television. On March 25, 1925,
Baird held his first public demonstration of "television"
at the London department store Selfridges on Oxford Street
in London. In this demonstration, he had not yet obtained
adequate half-tones in the moving pictures, and only
silhouettes were visible.
In the first week of October, 1925, Baird obtained
the first actual television picture in his laboratory. At
this time, his test subject was a ventriloquist's dummy,
"Stooky Bill," which was placed in front of the camera
Baird later recollected, "The image of the dummy's
head formed itself on the screen with what appeared to me
an almost unbelievable clarity. I had got it! I could
scarcely believe my eyes and felt myself shaking with
After much discussion with his business associates,
and further improvements, Baird decided to publicly
demonstrate television on Tuesday 26 January, 1926, again
at Selfridge's department store. This was the first
opportunity for the general public to see television.
The Baird company continued to publicize this
historic demonstration, and J. L. Baird's other scientific
breakthroughs as they feverishly worked to obtain
financial backing and construct a line of home receivers.
With Baird's transmitting equipment, the British
Broadcasting Corporation began regular experimental
television broadcasts on September 30, 1929. By the
following year, most of Britain's major radio dealers were
selling Baird kits and ready-made receivers through retail
and by mail order.
Richard Kadrey (firstname.lastname@example.org)