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SNEL, Willebrord (1580-1626). Eratosthenes batavus, de terrae ambitus vera quantitate. Leiden: George Abrahamsz van Maarssen for Jodocus Colster, 1617.
4o (212 x 154 mm). Full-page engraving showing the triangulation of Holland on p.168, numerous woodcut diagrams in text. 18th-century Italian paper boards, UNCUT AND UNOPENED (some chipping and small losses to spine).
FIRST EDITION OF SNEL'S FUNDAMENTAL WORK IN THE SCIENCE OF GEODESY AND OF GREAT IMPORT IN THE HISTORY OF NAVIGATION. In this work Snel outlines the principles of a new method for determining the length of the arc of the meridian by triangulation. "In 1615 he became deeply involved in the determination of the length of the meridian, selecting for this work the method of triangulation, first proposed by Gemma Frisius in 1533 and also used by Tycho. Snel developed it to such an extent that he may rightfully be called the father of triangulation. Starting with his house... he used the spires of town churches as points of reference. Thus, through a net of triangles, he computed the distance from Alkmaar to Bergen-op-Zoom (around 130 kilometers). The two towns lie on approximately the same meridian. Snel used the distance from Leiden to Zoeterwoude (about 5 kilometers) as a baseline. His instruments were made by Blaeu" (DSB).
From the mean of these two measurements Snel calculated the length of a degree to be 352,347 feet, a more accurate reckoning than any previous attempt. "His figure... showed the great error in the popular figure of 300,000 feet, which up to then was used by navigators. One navigator, at all events, was quick to see the advantage of using the lately calculated and more accurate figure, and used it upon his voyage to discover the North West Passage, in 1633. This was Captain Thomas James, after whom the bay to the south east of Hudson's Bay was named [see lot 280]. In the account of his 'strange and dangerous' voyage, as he described it, he related how, before leaving Bristol, he caused many small glasses to be made, whose part of time he knew with accuracy, and marked off the log like in accordance with Snellius's measure of feet to one degree" (Commander J.B. Hewson, A History of the Practice of Navigation, Glasgow, 1963, p.158). Snel also solved the so-called recession problem for three points, and the problem is often named after him. The title of this work is a tribute to the Greek mathematician Eratosthenes, who was famous for his measurement of the circumference of the earth. Norman 1963. A VERY FINE COPY.
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FIRST EDITION OF SNEL'S FUNDAMENTAL WORK IN THE SCIENCE OF GEODESY AND OF GREAT IMPORT IN THE HISTORY OF NAVIGATION. In this work Snel outlines the principles of a new method for determining the length of the arc of the meridian by triangulation. "In 1615 he became deeply involved in the determination of the length of the meridian, selecting for this work the method of triangulation, first proposed by Gemma Frisius in 1533 and also used by Tycho. Snel developed it to such an extent that he may rightfully be called the father of triangulation. Starting with his house... he used the spires of town churches as points of reference. Thus, through a net of triangles, he computed the distance from Alkmaar to Bergen-op-Zoom (around 130 kilometers). The two towns lie on approximately the same meridian. Snel used the distance from Leiden to Zoeterwoude (about 5 kilometers) as a baseline. His instruments were made by Blaeu" (DSB).
From the mean of these two measurements Snel calculated the length of a degree to be 352,347 feet, a more accurate reckoning than any previous attempt. "His figure... showed the great error in the popular figure of 300,000 feet, which up to then was used by navigators. One navigator, at all events, was quick to see the advantage of using the lately calculated and more accurate figure, and used it upon his voyage to discover the North West Passage, in 1633. This was Captain Thomas James, after whom the bay to the south east of Hudson's Bay was named [see lot 280]. In the account of his 'strange and dangerous' voyage, as he described it, he related how, before leaving Bristol, he caused many small glasses to be made, whose part of time he knew with accuracy, and marked off the log like in accordance with Snellius's measure of feet to one degree" (Commander J.B. Hewson, A History of the Practice of Navigation, Glasgow, 1963, p.158). Snel also solved the so-called recession problem for three points, and the problem is often named after him. The title of this work is a tribute to the Greek mathematician Eratosthenes, who was famous for his measurement of the circumference of the earth. Norman 1963. A VERY FINE COPY.