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HISTORICAL VIEW OP THE

It was at Padua that Galileo first avowed himself aconvert to the Copernican system. The earliest noticeof this appears in a letter to Kepler , returning thanksfor the present of his “ Mysterium Cosmographicum, ”in 1597- He seems, however, to have adopted thePtolemaic hypothesis in his public lectures for sometime after he had embraced the new doctrine ; but itmust be borne in mind how little of decisive proof hadyet been offered in support of it. A work on thesphere, however, which is decidedly Ptolemaic, longascribed to Galileo , appears to be of very doubtful au-thenticity. Both on this occasion, and afterwards, heprofessed great esteem for Kepler , though he did notconceal his dissent from his strange hallucinations.“ Kepler, ” said he, “ possesses a bold and free genius,perhaps too much so ; but his mode of philosophisingis widely different from mine.”

Galileo ’s reputation was now beginning rapidly toincrease. His lectures were attended by many personsof the highest rank ; and when, according to the con-stitution of the university, the period arrived for a newelection, he was not only re-appointed, but his salaryconsiderably augmented.

The appearance of a new star in 1604, before re-ferred to, of course attracted the diligent attention ofGalileo . Crowds flocked to his lecture-room, to hear hiscomments upon it ; and he appropriately took occasionto contrast their eagerness at the novelty and splendourof this spectacle, with their negligence in studying theordinary appearances of nature, not at all less wonder-ful, and far more instructive. He showed distinctly,from this star having no sensible parallax, that it mustbe situated far beyond the region of our atmosphere, towhich the Aristotelians referred all comets and trans-itory meteors, and to whose apprehension a new andvariable body engendered in the perfect and unchange-able celestial spheres was utterly contradictory.

Notwithstanding the hostility which these avowals offree enquiry produced, Galileo was a second time re-