When the fifth of my articles bearing the same title as this one arrived in April 2021, I looked at all of them and discovered that I had discussed apparatus named after 24 of our earlier colleagues! Who had I left out? After a bit of thought, I thought of Lloyd’s mirror, Faraday’s bag, Hope’s apparatus, Volta’s cannon and pistol, and Dewar’s “dewar.” Of course, there was Snell’s “law,” but that was stretching it too far! Since 2002, I have been writing page fillers for the American Journal of Physics, each consisting of a picture and a 100-word caption. About 800 of these have appeared to date. Therefore, I turned to them and found more than three score more names of physicists and their apparatus. Here are five of them.
James Dewar (1842–1923) is known as the first to liquefy hydrogen; this was a step on the way to...
