Television

History
Main article: History of television
The origins of what would become today's television system can be traced back to the discovery of the photoconductivity of the element selenium by Willoughby Smith in 1873, the invention of a scanning disk by Paul Gottlieb Nipkow in 1884, and Philo Farnsworth's Image dissector in 1927.
On March 25, 1925, Scottish inventor John Logie Baird gave a demonstration of televised silhouette images in motion at Selfridge's Department Store in London. In 1927, Baird transmitted a signal over 438 miles (705 km) of telephone line between London and Glasgow. In 1928, Baird's company (Baird Television Development Company / Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. He also demonstrated an electromechanical color, infrared (dubbed "Noctovision"), and stereoscopic television, using additional lenses, disks and filters. In parallel, Baird developed a video disk recording system dubbed "Phonovision"; a number of the Phonovision recordings, dating back to 1927, still exist.[1] In 1929, he became involved in the first experimental electromechanical television service in Germany. In November 1929, Baird and Bernard Natan of Pathe established France's first television company, Télévision-Baird-Natan. In 1931, he made the first live transmission, of the Epsom Derby. In 1932, he demonstrated ultra-short wave television. Baird's electromechanical system reached a peak of 240 lines of resolution on BBC television broadcasts in 1936, before being discontinued in favor of a 405-line all-electronic system developed by Marconi-EMI.
However, Herbert E. Ives of Bell Labs gave the most dramatic demonstration of television yet on April 7, 1927, when he field tested reflected-light television systems using small-scale (2 by 2.5 inches) and large-scale (24 by 30 inches) viewing screens over a wire link from Washington to New York City, and over-the-air broadcast from Whippany, New Jersey. The subjects, who included Secretary of Commerce Herbert Hoover, were illuminated by a flying-spot scanner beam that was scanned by a 50-aperture disk at 16 pictures per minute