Lockyer, Norman, Sir, 1836-1920, Seabroke, G. M. (George Mitchell), 1848-1918 · London, Macmillan and co. · leaf 43
making use of it to measurethe size of the earth and the inclination of the ecliptic c 2 20 STARGAZING : PAST AND PRESENT. to the equator. The method Eratosthenes followed inascertaining the size of the earth was to measure thearc between Syene and Alexandria by observing thealtitude of the sun at… … Fig. 6.—The First Meridian Circle. And now still another instrument is introduced, andwe begin to find the horizon altogether disregarded infavour of observations made on the meridian. The instrument in c^uestion was probably the inven-tion of Eratosthenes. It consisted of two circles ofnearly the…
Astronomy · Telescopes
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