11.5

**Dead medium: Mechanical TV: The Pioneers**

From: kadrey_AT_well.com (Richard Kadrey)

These are excerpts from the catalog from the exhibition at the Royal Ontario Museum, "Watching TV". The exhibition runs through September 15, 1996.

The catalogue is available from Royal Ontario Museum shops, CityStore 299 Queen Street, West, Ontario, Canada or from MZTV Museum. Cost - $11.50 Cdn., $10.00 US, plus shipping. Send email orders to mztv_AT_bravo.ca.

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: The Pioneers**


 * Nipkow**

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 transmitter.


 * Jenkins**

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 1925.

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 help."

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.


 * Baird**

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 apparatus.

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 excitement."

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 (kadrey_AT_well.com)