Mechanical Television

Television began as a mechanical contraption. The core idea was Paul Nipkow’s 1884 scanning disk: a spinning plate pierced with a spiral of holes, so that as it turned, each hole swept across the scene and sampled one horizontal line of light. Run a matching disk at the receiving end in step with the first, modulate a lamp behind it, and a crude moving image appears. Nipkow never built a working system, but in January 1926 the Scottish inventor John Logie Baird did, showing recognisable live moving faces to members of the Royal Institution in London — the first real television demonstration. His test subject was a dummy’s head called “Stooky Bill,” because the lamps were too hot and bright for a person to sit in front of for long.

For about a decade the mechanical system was television. The BBC broadcast a regular 30-line service from 1929, and by 1936 Baird had pushed his apparatus to 240 lines by scanning developed film on the fly. Millions of people saw their first moving picture on a screen this way: small, dim, flickering, tinged orange by the neon lamp, but unmistakably alive. It was a genuine medium, years ahead of anyone else.

Its limits were built into the hardware. Resolution and frame rate were both prisoners of a physical disk — how many holes you could fit, how fast you could spin it, how reliably you could keep two of them synchronised across miles of broadcast. Electronic scanning, using camera tubes and a cathode-ray screen with no moving parts, had none of those ceilings. The BBC settled the matter with a direct trial in 1936, alternating Baird’s mechanical 240-line system with Marconi-EMI’s electronic 405-line system week by week from Alexandra Palace. The electronic picture was sharper and steadier, and on 6 February 1937 the BBC dropped the Baird system outright. Within two years mechanical television had no broadcaster anywhere — the format that invented the medium, killed by the better way of doing the same thing.