Measure of the Earth [Hardcover]

What shape is the Earth? If you said round, of course you'd be right, and smart people have known this for a couple of thousand years, even if common sense tells you the Earth is flat (why, just look at it!). But the Earth is not perfectly round, not a perfect sphere; of course there are all those mountains and valleys, but in addition, it bulges out of the perfectly spherical. Before the eighteenth century, no one knew if it bulged north and south, or bulged outwards, although there were schools of thought that argued for both ways. They didn't have data to settle the issue. They needed good measurements, and how they first got the data is the exciting story of _Measure of the Earth: The Enlightenment Expedition That Reshaped Our World_ (Basic Books) by Larrie D. Ferreiro, a recounting of a French expedition to South America which answered the question of the Earth's shape. Ferreiro had encountered one of the explorers of the expedition in his research for a book on naval architecture, and was amazed to learn about the Geodesic Mission, and even more amazed that its story and accomplishments were not known even in France. It is, however, a great story of an important scientific achievement and the huge amount of effort it took for the simple purpose of satisfying scientific curiosity.

There were two schools of thought about the Earth's bulge - Newton said it bulged at the equator, and followers of Descartes said it bulged at the poles. No one had data. Ferreiro does an excellent job of giving a history of thought on the matter, and showing how scientists considered it important enough to set up a difficult and expensive expedition to get an answer by measuring a degree of latitude at the equator. Much of the story here involves the main scientists who were in charge of the expedition, their personality defects, and the conflicts between them. The surgeon of the expedition wrote of the scientists, even before they got to Peru, "They fight like cats and dogs and hide their observations from one another. It is not possible that they can finish this journey together." The biggest problem was that the mission leader, the astronomer Louis Godin, had no business leading anybody. He was arrogant, he high-handedly insisted that everything go his way, and he decided to keep information secret that was crucial for the proper functioning of his team. No one liked him. In addition, he jeopardized the costly expedition by, for instance, spending its money on a prostitute with whom he had become infatuated in Saint Domingue, where the group was delayed on its way to Peru. It is amazing that the expedition was ever completed. It started in 1735 and was expected to take three years; it took ten. There were horrendous complications from weather, war, mosquitoes, murder, and malaria, to mention just a few. The calculations were intimidating; for the first time ever, for instance, the curvature of the Earth had to be taken into account as the positions were calculated. Everything had to be corrected to be at sea level, and the sighting of the stars had to be brought into line with the land triangles. The result of all the hardship and conflict and expense was just a number: 56,753 toises, a toise being an old measure of length. That was the measure of a single degree of latitude at the equator, shorter than a degree at Paris and shorter still than a degree near the Arctic. The question was settled: the Earth conforms to Newton's prediction, and bulges at the equator.

The result was significant, but Ferreiro shows that there was far more to the expedition than just this confirmation of Newton. The Geodesic Mission was Big Science in action, for the first time the sort of transoceanic, international effort that would continue into our own time. The expedition opened new ways of thinking about South America, apart from just being a colony of Spain. The expedition was also to be followed in style by voyages by Alexander von Humboldt and by Charles Darwin; Ferreiro speculates that the accounts from these more famous travelers contributed to the world's unawareness of the Geodesic Mission. His welcome account rescues it from obscurity, and is a happy reminder that scientific effort is subject to the ravages of bad luck, the inability to predict the future, and shortages of cash, and that it is often a messy human endeavor involving prickly characters, even when there is eventual success.

****
"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

I subscribe to the aspirational adage, `You can't know it all; but you can try.' So over the years I have attempted to maintain a catholic attitude while browsing the subjects of History books, focusing more on works that put the `story' in History as opposed to any of my preconceptions about particular subject matter. My principal reason for purchasing `Measure the Earth' was a fond recollection of having read Dava Sobel's wonderful `Longitude' many years ago. The relatively familiar narrative of Horologist John Harrison's almost life-long quest to develop a reliable chronometer to enable mariners to reliably plot their east-west locations at sea, it suggested to me that since I had already ventured in one global direction, I may as well learn more about the other...all the while hoping it was as good a story.

Well, how good is the tale told in `Measure'? Let me put it this way. If you submitted this manuscript to a publisher as a novel, they would toss back in your face and tell you to come back when you had a believable yarn. In other words, you can't make this stuff up! An unprecedented expedition to an utterly foreign shore with shaky financial support, dreadful, and eventually almost fatal, leadership, waxing and waning political tides, almost non-existent communications, the list of horribles goes on and on. But they did it. They set out to measure one degree of latitude, and using instruments that even in the day were considered obsolete, they came so close to the now-consensus figure that the difference makes no never mind.

Actually, Author Ferreiro answers the rhetorical question of this review's title. It was the mission's very success that soon augured its obscurity because it encouraged other better-planned, and much better-funded, expeditions to South America, such as those of Darwin and Humboldt, which more forcefully grabbed both the scientific and popular imaginations. The true magnitude of the achievement was also compromised by the warring retrospective accounts of the principals and the fact that the mission was never seriously assessed until well into the 20th century.

That obscurity is actually the good news for the adventurous History reader who's only looking for a good story. If that description fits you, just buy `Measure' and congratulate yourself for your adventurous spirit. Terrific read.