Image on black and white television is deflected by a magnet, not unlike the Maltese Cross.
What it shows: The television is basically a sophisticated cathode ray tube. The electron beam in the TV is influenced by magnetic fields in the same way as in Crookes tubes.
How it works: The image on a black & white TV is formed by a single electron gun scanning the screen. Holding a strong magnet to the side or in front of the screen deflects the beam from its regular sweep pattern, distorting the image.