Museo Galileo
Virtual Museum
Earth's flattening at the poles

The hypothesis that the Earth was a flattened spheroid had already been voiced by Isaac Newton (1642-1727) on the basis of his theoretical investigations in Principia Mathematica (1687). His conjecture was confirmed by the measurements of the meridian arc made in the eighteenth century, including those of Pierre Bouguer (1698-1758) and Charles-Marie de la Condamine (1701-1774) in Peru.