The Measure of All Things: The Seven-Year Odyssey and Hidden Error That Transformed the World

Midst the chaos of the French Revolution, two astronomers set out in opposite directions from Paris to measure the world, one voyaging north to Dunkirk, the other south to Barcelona. Their findings would help define the meter as one ten-millionth of the distance between the pole and the equator. The Measure of All Things is the astonishing story of one of history's greatest scientific quests, a mission to measure the Earth and define the meter for all nations and for all time.

Yet when Ken Alder located the long-lost correspondence between the two men, along with their mission logbooks, he stumbled upon a two-hundred-year-old secret. The meter, it turns out, is in error. Pierre-François-André Méchain, made contradictory measurements from Barcelona and, in a panic, covered up the discrepancy. The quilty knowledge of his misdeed drove him to the brink of madness, and ultimately to his death. Only then did his partner, Jean-Baptiste-Joseph Delambre, discover the truth and face a fateful choice: what matters more, the truth or the appearance of the truth?

This is a story of two men, a secret, and a timeless human dilemma: is it permissible to perpetuate a small lie in the service of a larger truth? In The Measure of All Things Ken Alder describes a quest that succeeded even as it failed. It is a story for all people, for all time.