Come See the Earth Turn: The Story of Leon Foucault (2010) by Lori Mortensen, illustrated Raul Allen.

Have you stopped to linger at one of those pendulums at your local natural history museum? You know, the one where they set up the pegs and they get knocked down at certain intervals? Well, did you know that you’ve seen proof that the earth is turning and that we owe this bit of elegant evidence to Leon Foucault? 

Neither did I. Until this book came my way. Lori Mortensen sets up the story as an underdog tale: Leon was small as a baby, slow in his elementary school classes, dropped out of medical school. But he had a knack for building things and getting things just right. An accidental discovery leads him to his proof that the earth spins on its axis. 

Then they saw it — the pendulum began swinging away from the line traced in the floor.

In an instant, the scientists knew: The pendulum wasn’t swinging in a different direction. The earth was rotating beneath it.

Leon Foucault, the frail, awkward boy, had proved that the earth turned.

Raul Allen has contributed lovely illustrations, sepia toned with an emphasis on gorgeous lighting.

Finally, a little quibble. The one thing that would push this over into an all-time favorite would be a simple explanation of the science behind the pendulum, and the scientific process of creating solid evidence to prove your hypothesis. The emphasis is on the history and there’s a missed opportunity to explain the scientific thinking behind this discovery.