iet. iv. Tycho Brahe, and Copernicus. - 67

From these discoveries, Astronomy began toassume a new form, and most of the celestialphænomena were soon accounted for, accordingto their real or physical causes. Des Cartes,Gassendus, Casiini, and Newton, employedthemselves, with the utmost diligence, in im-proving and perfecting this science: and the lastof these great men, in particular, has establishedthe Copernican system upon such an everlastingbasis of mathematical demonstration, as cannever be shaken, but must last as long as thepresent frame of nature continues in existence.

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