_Ast. Mod. Hist_., pp. 86, 87).

[6] Kepler tells us that Tycho Brahe was pleased with this
device, and adapted it to his own system.

[7] _Hist. Ast._, vol. i., p. 354.

[8] _Hist. of Phys. Ast._, p. vii.

[9] "Est enim Astronomi proprium, historiam motuum coelestium
diligenti et artificiosa observatione colligere. Deinde causas
earundem, seu hypotheses, cum veras assequi nulla ratione possit
... Neque enim necesse est, eas hypotheses esse veras, imo ne
verisimiles quidem, sed sufficit hoc usum, si calculum observationibus
congruentem exhibeant."




BOOK II. THE DYNAMICAL PERIOD



5. DISCOVERY OF THE TRUE SOLAR SYSTEM--TYCHO BRAHE--KEPLER.


During the period of the intellectual and aesthetic revival, at the
beginning of the sixteenth century, the "spirit of the age" was
fostered by the invention of printing, by the downfall of the
Byzantine Empire, and the scattering of Greek fugitives, carrying the