It was 90 years ago this year that Scottish inventor John Logie Baird publicly demonstrated his "televisor", the forerunner of the modern television.

The demonstration on 26th January, 1926, involved the transmission of a small moving image - measuring just 8.8 by five centimetres - of the face of his business partner, Daisy Elizabeth Gandy, onto a screen in a different room.

The device has been described as working rather like a radio but had an attached rotating mechanism that generated video as well as sound (modern televisions, in contrast, use electronic scanning).

PICTURE: Diane Griffiths/CC BY 2.0

The demonstration, which took place in a laboratory in Soho, London, in front of members of the Royal Institution and a journalist from The Times newspaper, came two years after Baird first managed to transmit a flickering image over a distance of about three metres.

The following year - in 1927 - Baird managed to transmit content along a 705 kilometre long telephone line between London and Glasgow and in 1928 he completed the world's first TV transmission in colour, the same year he also conducted the first trans-Atlantic TV broadcast.

In 1929, his company - the aptly named Baird Television Development Company - brought out the world's first mass produced TV set, a mechanical set.

The mechanical television was soon made redundant by the introduction of the electronic television in the Thirties but Baird continued to work in developing the medium and in 1944 he gave the world's first demonstration of a fully electronic colour television.

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