

Dr. Moll on the Invention of Telescopes. 325 



inventor under the obligation of making a telescope through 

 which one could see with two eyes. 



Two days afterwards, the 4th of October, 1608, we find the 

 following entry upon the Journals of the States : 



' Sabathi, 4 October, 1608. 



* Resolved, that inclusive of the communication held the 2d 

 instant with Hans Lippershey, a native of Wesel, inventor of 

 the instrument to see at a distance, one person from each pro- 

 vince will be named, to examine and to try the said instru- 

 ment on the turret of the mansion of his Excellency (Prince 

 Maurice) , and to investigate whether it is likely to be of such 

 utility as is generally believed ; and, in such a case, to treat 

 with the inventor, that he undertakes to make three such 

 instruments of rock-crystal (christael de roche), for which he 

 asks a thousand florins a-piece ; that he moderates his charge, 

 and promises never to transmit his invention to anybody.' 



In this piece we have the counterpart of what happened to 

 Galileo at Venice. Here we have the members of the States- 

 General ascending the turret on Prince Maurice's house, to 

 examine a distant object with the newly-invented spy-glass, as 

 the Venetian senators mounted the steeple of St. Mark ; and 

 probably Lippershey was equally tired as the Italian philoso- 

 pher, with snowing off his instrument to persons requiring 

 telescopes to make them see with two eyes. 



The mention which, in this early stage of the invention, is 

 made of rock or mountain crystal, appears very curious. It 

 seems that, in this beginning, the difficulty of procuring glass 

 fit for telescopes was equally as great as it is now, and rock 

 crystal was frequently resorted to, in the constructiom.of object- 

 glasses. This appears, amongst others, from a passage in 

 Hevelius, who, however, gives the preference to glass. At this 

 present day the Parisian optician, Cauchoix, constructs tele- 

 scopes of rock or mountain-crystal, which he calls lunettes 

 vitro-crystal lines ; but which, in my opinion, are inferior to 

 glass telescopes of equal size. One consequence may be 

 deduced from the circumstance of rock-crystal being used in 

 the construction of these telescopes, which is, that this spec- 

 tacle-maker must have been well skilled in his profession, 



