Page 520 - 89 history of astronomy_opt

Pound measured the ellipticity = 1/(13.25).
W. Herschel supposed the spots to be
masses of cloud in the atmosphere–an opin-
ion still accepted. Many of them were very
permanent. Cassini’s great spot vanished
and reappeared nine times between 1665
and 1713. It was close to the northern mar-
gin of the southern belt. Herschel supposed
the belts to be the body of the planet, and
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