The research that led to the discovery and understanding of cathode rays involved many different scientists from several countries and spanned more than a decade. Today, devices ranging from the oscilloscope to the electron microscope to the television set rely upon cathode rays and cathode-ray tubes.

Pioneers in the field of cathode rays, such as Michael Faraday, performed considerable research involving electricity; in particular, they were interested in the behavior of electrical current as it crossed the gap between an anode and a cathode. In order for this to occur, the two electrodes were placed within a tube from which much of the air was evacuated. During the early 1800s the technology necessary to create a true vacuum within the tube did not exist. Still, Faraday and others noticed that, even in a partially evacuated tube, a slight fluorescent glow could be detected when a current...