52a

HISTOEY OF PHYSICAL ASTEON'OHY.

astronomer, “ how I wish that we could have one hearty laugh together!Here, at Padua , is the principal professor of philosophy, whom I haverepeatedly and earnestly requested to look at the moon and planetsthrough my glass, which he pertinaciously refuses to do. Why are younot here ? What shouts of laughter we should have at this gloriousfolly, and to hear the professor of philosophy in Pisa labouring before theGrand Duke with logical arguments, as with magical incantations, tocharm the new planets out of the sky!"

Galileo can hardly be considered an independent inventor of thetelescope. Admitting that he obtained no other account of the Dutch invention, than that a spectacle maker had succeeded in executinga perspective instrument by means of which distant objects appearednearer, still the fact of his having received such a hint deprives hislabours in a great degree of the character of originality. When once aproblem is known to he resolvable, the difficulties which it involves may thenbe overcome with comparative ease by a strong concentration of the mentalpowers upon it. But, in justice to the original inventor, and the countrywhich gave him birth, it is but right to mention, that more than one ofthe Dutch instruments had found their way into Italy about the timewhen Galileo was led to construct his first telescope. Sirturus, writingin 1018, makes the following statement:—“A Frenchman proceeded toMilan in the month of May, 1009, and offered a telescope for sale to theCount di Fuentes.”* Again, in a letter from Padua , dated August 31,1609, Lorenzo Pignoria announces to Paolo Gualdo that Galileo hadbeen appointed lecturer at Padua for life on account of a perspective,like the one which was sent from Flanders to Cardinal Borghese . “ Wehave seen some here," adds the writer, “and truly they succeed well.”f

We dismiss, as an unfounded calumny, the assertion of Fuccarius, thatGalileo had actually seen one of the Dutch telescopes, nor can we evenadmit, in the face of his own words to the contrary J, that he receivedany hint relative to the peculiarity of their construction; but the noto-riety of the invention, as confirmed by the preceding extracts, could notfail to have operated as a powerful incentive to his efforts.

Some writers have been disposed to think that the Dutch telescope wasconstructed upon a different principle from Galileo ’s instrument. Pro-ceeding upon the tradition of its having been originally exhibited as anamusing toy, by producing an inverted image of a weathercock, theyhave hence inferred that it was composed of two convex lenses, like themodern astronomical telescope. This conclusion, if true, would certainlygo far to enhance Galileo ’s merit, but it rests on so narrow a foundationas to be totally inadmissible, being suggested solely by the vague traditionjust mentioned. On the other hand, Descartes and De Rheita positively

* Sirturus de Telescopic*, Franc., 1618.

f “ Di nuovo non abbiamo altro se non la reincidenza di S. Serenita, e ricondotti diLettori, fra’ quali il Sig. Galileo ha buscato 1000 fiorini in vita, e si dice col benefiziod’un occhiale simile a quello, che di Fiandra fu mandato al Card. Borghese . Se nesono veduti di qua. e veramente fanno buona riuscita .”—(Letters d’Uomini IUustri,p. 112, Venez., 1744.

+ The following are the terms in which he alludes to the information he receivedrespecting the Dutch invention on the occasion of his visit to Venice , as mentioned inthe text:—“ Giunsero nuove, che al Sig. Conte Maurizio era stato presentato da unOlandese un occhiale, col quale le cose lontane si vedevano cosi perfettamente, comese fussero state molto vicine, ne piii fu aggiunto." (Opere di GaU % Edit. Pad., 1744,tom. ii. p. 267.)