PHYSICAL AND MATHEMATICAL SCIENCES. 181

the flames by his own hand, as a pious, sacrifice beforedevoting himself to the life of a missionary.

We cannot better conclude our account of Galileo and his discoveries, than by quoting the able summaryof his character and labours given by professor Play-fair : —

“ One forms, however, a very imperfect idea of thisphilosopher from considering the discoveries and inven-tions, numerous and splendid as they are, of which hewas the undisputed author. It is by following his rea-sonings, and by pursuing the train of his thoughts, inhis own elegant, though somewhat diffuse, exposition ofthem, that we become acquainted with the fertility of hisgenius—with the sagacity, penetration, and compre-hensiveness of his mind. The service which he ren-dered to real knowledge is to be estimated, not only fromthe truths which he discovered, but from the errorswhich he detected ; not merely from the sound princi-ples which he established, but from the pernicious idolswhich he overthrew. His acuteness was strongly dis-played in the address with which he exposed the errorsof his adversaries, and refuted their opinions, by com-paring one part of them with another, and proving theirextreme inconsistency. Of all the writers who havelived in an age which was yet only emerging from ig-norance and barbarism, Galileo has most entirely the toneof true philosophy, and is most free from any contami-nation of the times in taste, sentiment, and opinion.” *

By the writings of Copernicus, of Kepler, and Ga-lileo , the solar system, and the subordinate series oftruths referring to the theory of motion, were so com-pletely established and unanswerably demonstrated, thatnothing was wanting but time to allow the opinions ofmen to come gradually round to the truth. The deter-mined adherents of the old systems gradually disappearedfrom the scene, and the younger generation were opento profit by the light now afforded; and, in a few years,Tycho and Ptolemy had no followers.

* Dias. p. HS.

N 3