THE HISTORY OF THE TELESCOPE. 97 



Bacon, to Porta, and to many others who have written on optics; but 

 to find the name of Satan iu the list is certainly surprising. Still we 

 read that a very learned man of the seventeenth century, named Arias 

 ^lontanus, tinds in the fourth chapter of Matthew, eighth verse, evi- 

 dence that Satan possessed, and probably invented, a telescope; othei- 

 wisc, how could he have •' sliown him all the kingdoms of tlie world 

 and tlie glory of them*'!'* It seems tc> be well established now, liow- 

 ever. that Franz Lippershey, or Lii)pe]sheim, a spectacle maker at 

 Middleburg, was the real inventor of the telescope, and that ( Galileo's 

 first telescope, avowedly suggested by news of the Hollander's achieve- 

 ment, was an independent invention. 



That this discovery was really an accident we may be quite sure, 

 for not only was there no developed theory of optics at that time, but 

 even the law of refraction, which lies at the basis of such theory, was 

 quite unknown. So, too, it seems to me quite certain that Galileo's 

 invention nuist have been empirical and guided by somewhat precise 

 information, vsuch as that the instrument consisted essentially of two 

 lei]ses, of which one was a magnifying and the other a diminishing 

 lens. .Vt least, that (ialileo's telescope was like that of the Hollander; 

 that, theoretically considered, it is not so sinqde as that made of two 

 magnifying lenses, as is evinced by the fact that Kepler, the first 

 l>liilosopher to establish an api)roximate theory of optical instruments, 

 only two years later invented the latter and prevailing form; and 

 finally, that (xalileo published no contributions to the theory of optics, 

 seem (piite sufticient reasons for such a belief. But, in any case, (Ia- 

 lileo's merit is in no wise lessened by having failed to do what coiUd 

 not be done at that time, and the value of his discoveries in emanci- 

 ])ating men's minds from autliority in matters of pure reason is incal- 

 culable. 



No other discoveries <»f gieat moment were made until over a gen- 

 eration after (raliUi* i)rove(l the existence of spots on the sun in Kill. 

 This cessation of activity was doubtless owing to the dilUculty of se- 

 curing telescopes of greater clficiency than that ]»ossessed by (lalileo, 

 and wl\ich he would hardly hav(^ left until its ])owers of discovery had 

 been fnlly exhausted in his own hands. By the middleof the seventeenth 

 century, however, several makers of lenses had so far improved the 

 methods of grinding and ])olishing, that telescoi»(\s notably su])erior in 

 ]»()\ver to that of (i^ableo were procurable. Of these Torricelli, Divini, 

 and Campani, all Italians, — Auzout, Avho constructed a te]escoi)e 000 

 feet in length, though no means was ever found for directing such an 

 enormous instrument towards the heavens, — but above all, Huyghens, 

 have W(m distinction as telescope -makers. The last named philos- 

 oj)her discovered, by means of a telescope of his construction, the lar- 

 gest satellite of Saturn in 1(555, tlius adding a fifth member to the list 



*The history of the telescope is admii-ably treated in Poggendorft's Gcuchkhtc 

 dvr Phjisil:, from which the stateuieuts above are takeu. 



H. Mis. lU 7 



