John Logie Baird, a Scottish inventor, gives the first public demonstration of a pictorial-transmission machine he calls a televisor. Baird's invention used mechanical rotating disks to scan moving images into electronic impulses. This information was then transmitted by cable to a screen where it showed up as a low-resolution pattern of light and dark. Baird's first television program showed the heads of two ventriloquist dummies, which he operated in front of the camera apparatus out of view of the audience. The principle behind transmitting images through electric currents had actually existed since 1875, but Baird was the first to make practical advances in television technology. In 1928, he made the first overseas broadcast from London to New York and the same year demonstrated the first colour television. His early British broadcasts never reached more than about 100 television sets, but he was responsible for launching a revolution in communication and entertainment.