Johnson is a science writer for the New York Times and has written this book as a top ten list of science experiments. I guess that makes him the Letterman of science. Johnson's list is not the ten greatest discoveries of science but rather a list of experiments done by individuals that he finds to be important, elegant and accessible. They are experiments conducted by individuals and were done on a very human scale, often on a table top.
Do you remember hearing about Galileo dropping things from the leaning tower of Pisa? Johnson believes that never happened. He gives a detailed account of the experiment that Galileo did, rolling balls of different materials down an inclined track, timing their descent by singing. This allowed Galileo to show that heavier objects do not fall faster than light ones and to figure out the math for the acceleration of falling bodies. Newton would develop his laws of motion based on Galileo's work.
He talks about Isaac Newton but not about gravity. Newton did a series of experiments using prisms which revealed that light is made up of waves and showed that color is derived from white light.
There are several experiments in electromagnetism, Michael Faraday, James Joule, A.A. Michelson, Robert Millikan. Millikaa's experiments with oil droplets, magnetic fields and radium, in which he discovered the electron, are the most complex in the book. Johnson tried to duplicate them and was not successful, blaming himself for being unable to control the apparatus properly.
I don't know whether the experiments Johnson chose were the most beautiful or not. He left the impression that he wasn't so confident in his choices either.