July 31

Primo Levi, the Italian chemist and writer whose memoir of Auschwitz became a touchstone of witness literature, was born in Turin.

Ignatius of Loyola, founder of the Society of Jesus and author of the Spiritual Exercises, died in Rome.

Fritz Hommel, a German Assyriologist and historian of Babylonia and Assyria, was born in Ansbach in Bavaria.

On 31 July 1790, the first U.S. patent was granted to Samuel Hopkins for an improved process of making potash; it was signed by President George Washington.

On 31 July 1971, Apollo 15 astronauts David Scott and James Irwin first drove the battery-powered Lunar Roving Vehicle across the Moon's surface, greatly extending how far a crew could explore.