Key Moments in 1920s Television

The invention of the television was the work of many individuals in the late 19th century and early 20th century. Individuals and corporations competed in various parts of the world to deliver a device that superseded previous technology. Many were compelled to capitalise on the invention and make profit, while some wanted to change the world through visual and audio communication technology.

...***Key Moments in Early Television*** (Pre-20th Century to 1910s)

###  The 1920s

By the 1920s, when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems. He created his prototype in a little village called Santa Cruz on the island of Trinidad where he was recovering from an illness. He had also started work on the first colour television.

### 1923

#### December: First transmission of images

American inventor, Charles Francis Jenkins begins to work on television. He published an article on "Motion Pictures by Wireless" in 1913, but it was not until 1923 that he transmits moving silhouette images for witnesses.

### 1925

#### March 25: First public demonstration of moving images

John Logie Baird gives the first public demonstration of televised silhouette images in motion, at Selfridge's Department Store in London. Since human faces had inadequate contrast to show up on his primitive system, he televised a talking, moving ventriloquist's dummy named "Stooky Bill", whose painted face had higher contrast. nature.com (pages 505-6)

#### June 13: First synchronised pictures and sound

Charles Francis Jenkins publicly demonstrates synchronised transmission of pictures and sound.

#### June 30: Charles Francis Jenkins' US patent for wireless transmissions

Charles Francis Jenkins is granted a U.S. patent for Transmitting Pictures over Wireless (filed on March 13, 1922).

### 1926

#### January 26: First demonstration of television

   John Logie Baird demonstrates the transmission of an image of a face in motion by radio. This is widely regarded as the first television demonstration in history. The subject was Baird's business partner Oliver Hutchinson. Baird's system used the Nipkow disk for both scanning the image and displaying it. A bright light shining through a spinning Nipkow disk set with lenses projected a bright spot of light that swept across the subject. A selenium photoelectric tube detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronised with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one scan line of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognise a human face.

#### May 7: Léon Theremin

In the Soviet Union, Léon Theremin had been developing a mirror drum-based television, starting with 16-line resolution in 1925, then 32 lines and eventually 64 using interlacing in 1926. As part of his thesis, Theremin electrically transmits and then projects near-simultaneous moving images on a five-foot square screen. By 1927 he achieved an image of 100 lines, a resolution that was not surpassed until 1931.

#### December 25: First example of "all-electronic" television

    Kenjiro Takayanagi demonstrates a television system with a 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan. Takayanagi took the important step of using a cathode ray tube to display the received signal, thereby developing the first "all-electronic" television set. This prototype is still on display at the Takayanagi Memorial Museum at Shizuoka University, Hamamatsu Campus. By 1927, Takayanagi improved the resolution to 100 lines, which was unrivalled until 1931. By 1928, he was the first to transmit human faces in halftones. His work had an influence on the later work of Vladimir K. Zworykin. His research toward creating a production model was halted by the US after the Japanese surrender at the end of World War II.

### 1927

#### January 1: The British Broadcasting Corporation

The British Broadcasting Company becomes the British Broadcasting Corporation.

#### April 7: Herbert Ives and Frank Gray

Herbert E. Ives and Frank Gray of Bell Telephone Laboratories give a dramatic demonstration of mechanical television. The reflected-light television system included both small (2" x 2.5") and large (24" x 30") viewing screens. Both sets were capable of reproducing reasonably accurate, monochromatic moving images. Along with the pictures, the sets also received synchronised sound. Subjects of the telecast included Secretary of Commerce Herbert Hoover. Television historian Albert Abramson underscored the significance of the Bell Labs demonstration: "It was in fact the best demonstration of a mechanical television system ever made to this time. It would be several years before any other system could even begin to compare with it in picture quality."

#### May 24-27: First long-distance television broadcast

John Logie Baird transmits a signal over 438 miles (705 km) of telephone line between London and Glasgow. scotsman.com

#### September 7: The Television Society and Philo T Farnsworth

The Television Society is founded. With Royal patronage, it becomes the Royal Television Society in 1966.

Philo T. Farnsworth demonstrates his first fully electronic system in San Francisco, which did not require a Nipkow disk.

#### September 20: First electronic image recordings

John Logie Baird makes first electronic image recordings onto ordinary 78 rpm gramophone records. He called this system “Phonovision”. blog.scienceandmediamuseum.org.uk

#### December 30: "Noctovision"

John Logie Baird demonstrates “Noctovision” (infra-red television) to the Royal Institution. blog.scienceandmediamuseum.org.uk

### 1928

#### January 13,: World's first television station

WRGB (then W2XB) start as the world's first television station. It broadcast from the General Electric facility in Schenectady, NY. It was popularly known as "WGY Television".

#### February 8: First transatlantic television broadcast

John Logie Baird's company (Baird Television Development Company/Cinema Television) broadcasts the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. bairdtelevision.com

#### July 2: First television station to broadcast to the general public

The Jenkins Television Corporation opened the first television broadcasting station in the U.S., named W3XK, and first sends transmissions from the Charles Jenkins Laboratories in Washington and, from 1929, on from Wheaton, Maryland, five nights a week. At first, the station could only send silhouette images due to its narrow bandwidth, but that was soon rectified and real black-and-white images were transmitted.

#### July 3: First demonstration of colour television

John Logie Baird demonstrates colour television. blog.scienceandmediamuseum.org.uk

#### August 10: Stereoscopic television

Television images in, apparently, three dimensions are demonstrated for the first time in the Baird Laboratories in Long Acre, before an audience of scientists and representatives of the press. bairdtelevision.com

#### September 22-29: "Televisors"

John Logie Baird's Television Development Company demonstrates their model A, B & C 'televisors'.

### 1929

#### March 5: First BBC broadcast

John Logie Baird broadcasts television using the BBC’s London transmitter. blog.scienceandmediamuseum.org.uk

#### July: Experiments in Germany

John Logie Baird becomes involved in the first experimental mechanical television service in Germany. John Logie Baird: Television Pioneer By R. W. Burns

#### September 30: BBC test transmissions

The British Broadcasting Corporation (BBC) and John Logie Baird begin daily experimental broadcasting of 30-line television transmissions using the BBC’s 2LO transmitter.

#### November

John Logie Baird and Bernard Natan of Pathé establish France's first television company, Télévision-Baird-Natan.

***Key Moments in 1930s Television*...**