"Thus, ... this type of indirect measurement was really child's play to the Alexandrians. They were eventually able to measure by indirect means the radius of the earth, the diameter of the sun and moon and the distance to the moon, the sun, the planets, and the stars. That we can measure such physically inaccessible lengths and do so, moreover, with an accuracy as great as we wish, seems, at first blush, incredible." -- Morris Kline
In the Principia, Newton first raised the question of the Earth's shape. Continental scholars influenced scientific efforts to solve the problem in Paris, while their French colleagues helped in advancing a theory on the Earth's shape. The evolution of French mechanics proved not to be the replacement of a Cartesian pattern by a Newtonian / Leibniz concept, failing Kuhn's paradigm of scientific revolutions. Instead, a complex process involving various tools of research and coordination from the entire scientific world contributed. Larrie Ferreiro both explores and reports the innumerable phases, and aspects of technical problems underlying the historical development of the post-Newtonian mechanics. He embeded his technical discussion in a biography framework that involves society, politics and institutional history.
During the eighteenth century, the spread of Newtonian physics in the French scientific community, Newton's writings contributed only a small part to the central thesis of the work done on the shape of the earth. Continental scholars, especially Leibniz, influenced the entire French proceedings, and many French scholars participated in defining the final earth's shape theory. The evolution of Enlightment physics, proved to be more than a mere replacement of a scientific discipline framework with another, but a rather complicated process involving many areas of research and contributions from the entire scientific world.
Prior to 1735, South America was largely 'terra incognita' to most Europeans, but on that year, the French Academy of Sciences sent a joint mission, of French and Spanish scholars to Quito, a South American Spanish province (present-day Ecuador) to study the curvature of the Earth at the Equator. Equipped with telescopes and quadrants, the mission members considered the transfer of scientific knowledge from Europe to the Andes as a sacred fire transmitted esotericly through the European astronomical instruments to curious observers in South America. This expedition would put South America, on the world map for centuries to come, at least in the minds of Europeans.
In 1735, a team of French and Spanish scientists traveled to South America as members of the Equator Geodesical Expedition. Their mission for this expedition was to attempt to find the true shape of planet Earth. The earlier work of great physicists Isaac Newton and Huygens suggested it flattened at the poles, while bulging around the equator. Or was the bulge rather at the bottom pole than at the equator, as it is revealed in the Quran, and debated earlier with Moslem astronomers in Andalusia. To settle this matter, the "Académie des Sciences, a Paris," commissioned two metrological expeditions: one to Lapland, near the North Pole, and the other to Quito, near the equator. Measuring the length of a meridian arc of one degree at each of these two sites and comparing the results would resolve the issue. As it turned out, Newton-Huygens thesis was correct. The equatorial expedition entailed unprecedented international cooperation, because Spain had long forbidden foreigners to travel in its American dominions. It had provided a wide European public with a rare information about equatorial South America, land of the Incas, the fabled Amazons and El Dorado.
For the next decade, the mission traveled widely, conducting geodesical measurements. Its members had gathered information about a territory that Europeans still knew little, after about two centuries of the Spanish conquest of the Inca territories. The expedition resulted in a wide range of results, some addressed the journey itself, while others were concerned more broadly with the region. Ferreiro searched, and wrote one of the best reconstructed travel stories to result from the expedition. He recounts in detail the historical joint expedition of France and Spain, to discover the shape of the Earth, and determine its size. A historical account of the Inca empire; with a description of the province of Quito. Expected to take about two years, the expedition to what is now Peru, extended over almost a decade. While reading the fascinating and engaging account of the complex project, filled with examples political conspiracy, dysfunctional interpersonal relations, and wasted efforts that Ferreiro recounts with apparent enthusiasm. But the mission was ultimately successful and became a historical as well as a scientific achievement.
Measuring the New World: Enlightenment Science and South America
The Problem of the Earth's Shape from Newton to Clairaut: The Rise of Mathematical Science in Eighteenth-Century Paris and the Fall of 'Normal' Science