Page 450 - 89 history of astronomy_opt

Schwabe, of Dessau, began in 1826 to
study the solar surface, and, after many
years of work, arrived at a law of frequency
which has been more fruitful of results than
any discovery in solar physics.[5] In 1843 he
announced a decennial period of maxima
and minima of sun-spot displays. In 1851
it was generally accepted, and, although a
period of eleven years has been found to be
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