Average Reviews:
(More customer reviews)Despite its title and subtitle, there is much more in this book than a description of Eratosthenes's attempt to measure the earth's circumference. Roughly the first half of the book contains information on the ancient world as it existed at about the time that Eratosthenes lived. Topics discussed include: the origin and evolution of the city of Alexandria, the people who lived and worked there, the Museum and Library, other landmarks, the politics, the local kings, the thinkers of the period, etc. In the second half of the book, more technical details are presented on Eratosthenes' measurement of the earth's circumference, e.g., his methods, his results as given in the ancient unit "stade", detective work in converting the stade into modern miles, etc. Also discussed are attempts, over the centuries since Eratosthenes's time, to explore and map the globe and even circumnavigate it. The writing style is scholarly, often witty and generally quite engaging - the second half, in my opinion, is particularly gripping.
Unfortunately, there is an error on page 140, near the bottom. Here it is stated that "... the first day of spring in the northern hemisphere is the day when the earth's axis is perpendicular to the plane of its solar orbit". This is incorrect; the earth's axis is never perpendicular to the plane of its solar orbit (the ecliptic); it is currently at about 23.5 degrees off from being perpendicular to the ecliptic and this angle varies somewhat (oscillates) over long periods of time. The first day of spring (vernal equinox), is the day when solar rays hit the earth's surface perpendicular at the equator at local noon, i.e., the sun is directly overhead, as correctly stated in the sentence following the above quote. Simply eliminating the sentence that includes the above quote would easily fix the problem.
Aside from this minor point, this is a book that can be enjoyed by anyone; however, based on its scholarly bent and its subject matter, it will likely be most relished by the more serious ancient history/science buffs.
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