The Astronomical Observatories of Jai Singh c6.s1.t1.62

c6.s1.t1.62

This topic of ‘ Climates ’ recalls a most interesting chapter in the history of civilization. It exercised the attention of such astronomers and astrologers as Eudoxus, Eratosthenes, Hipparchus, Manilius, Ptolemy, Dorothea of Sidon, etc., etc. The subject presented difficulties. The number of climates assumed varied, but generally a chorographic system, which applied the seven planets to the seven zones or climates, prevailed. Also, according to Paul of Alexandria, “ each sign corresponds to a climate or parallel, and by virtue of its Trigon to each quarter.” For the mathematicians, the problem was to find a progression corresponding to ascensional differences. They took the length of the day as the measure,¹ and progressed from one climate to another by half hour steps. (See appendix C.)