494 Dr. Moll on the Invention of Telescopes. 



of discovering the satellites in 1610. Thousands, certainly 

 hundreds, saw the satellites in 1655 ; and why should not 

 John, like other people ? I, therefore, positively deny that 

 any intention is shown in Borel's book, to depreciate the 

 merits of Galileo ; and, as far as Boreel is concerned, con- 

 sidering his character and station in life, it is absurd to say, 

 that his evident object was to make Galileo's share in the 

 invention as small as possible ; but if Boreel really under- 

 valued Galileo's merits, let the English author quote, and 

 point out the place where he did so. I must offer another 

 remark to this same anonymous author, I am quite prepared 

 to believe that the telescopes made by Galileo's own hands 

 were as perfect as art could make them at the time; but 

 it is to be lamented, if the original telescope of Galileo still 

 exists in Florence, that no Italian philosopher has favoured us 

 with an account of its performance. We have, however, a sort 

 of criterion of what could be done by it. The belts of Jupiter 

 were, as far as I know, never seen by Galileo ; they were 

 observed, after his death or blindness, with instruments made 

 by Evangelista Torricelli. But the author of the English 

 life of Galileo asserts, as proof of the inferiority of the Dutch 

 telescopes, that, in 1637, ' Gaertner, or, as he chose to call 

 himself Hortensius, wrote to Galileo, that no telescope could 

 be procured in Holland, sufficiently good to show Jupiter's 

 disk, well defined*.' Hortensius wanted more than could be 

 accomplished in his time ; and even now, telescopes of a cer- 

 tain size, which show Jupiter's disk well defined, are not of every 

 day's occurrence. Does this author know many telescopes 

 excepting those made by Mr. Dollond or by Mr. Tully, capable 

 of showing Jupiter's disk, well defined; nay, does he know one 

 single telescope, not achromatic, capable of answering the 

 claim of Hortensius. The anonymous author favours his reader 

 with a translation of Hortensius's name, which he pronounces 

 to be Gaertner. He is mistaken, however: Gaertner certainly 

 is the German of Hortensius ; but he was not a German, 

 and his name, in his mother tongue, was Van den Hore. 



We find the celebrated Peirese, as late as 1622, doubting 



* P. 25. 



