"The truth belongs to everyone, but error is ours alone." -- The Measure of All Things Amidst the chaos of the French Revolution, two intrepid 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, a standard that has since swept the planet. 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, and a drama worthy of the great French playwrights.