In the 18th century, Europe's scientific community was torn between two opposing theories: Descartes' argument that the Earth was spherical, and Newton's contention that it was flattened at the poles. Recognizing that the answer was the key to securely navigating the earth's oceans, France and Spain organized a joint expedition to colonial Peru. Their goal was to measure a degree of latitude at the Equator; by comparing this measurement to one taken back in Europe, they would be able to determine the planet's shape and put an end to the debate. But what seemed a straightforward scientific exercise was almost immediately marred by a series of unforeseen catastrophes: treacherous terrain, deeply suspicious locals, and the voyagers' own hubris. A thrilling tale of adventure, political history, and scientific discovery, Larrie D. Ferreiro's Measure of the Earthrecounts the greatest scientific exhibition of the Enlightenment through the eyes of the men who completed it--pioneers who overcame tremendous adversity to traverse the towering Andes Mountains and discern the Earth's true shape.

Larrie D. Ferreiro is the author and editor of several books on the history of science and technology, including Ships and Science, which received the North American Society for Oceanic History's John Lyman Award for Best Book in Science and Technology. A frequent maritime contributor to the History Channel and the Discovery Channel, he was an on-screen historical consultant to a BBC documentary about the Geodesic Mission. He lives in Fairfax, Virginia.