13. J.J. Thomson, with his deflection modifications and phosphorescent screen, had invented the cathode ray tube. The name would be shortened to “CRT,” and it would come to be manufactured in the millions in the last half of the next century for use in television sets and computer monitors. Users are cautioned against getting too close to the screen, as Röntgen’s X-rays come streaming out the front as the electrons crash into the shadow-mask used in color versions of the tube. J.J. Thomson would probably disapprove of the commercial use of his experimental apparatus, as he was opposed to the concept of profitable science.