140 DISSERTATION SECOND. [part i. 



nary, is now well known, and needs not to be described ; 

 but the sensations which the view must have communicat- 

 ed to the philosopher who first beheld it, may be con- 

 ceived more easily than expressed. To the immediate 

 impression which they made upon the sense, to the won- 

 der they excited in all who saw them, was adt'ed the 

 proof, which, on reflection, Ihey afforded, of the close re- 

 semblance between the earth and the celestial bodies, 

 whose divine nature had been so long and so erroneously 

 contrasted with the ponderous and opaque substance of 

 our globe. The earth and the planets were now proved 

 to be bodies of the same kind, and views were entertained 

 of the universe, more suitable to the simplicity, and the 

 magnificence of nature. 



When the same philosopher directed his telescope to 

 the fixed stars, if he was disappointed at finding their magni- 

 tudes not increased, he was astonished and delighted to 

 find them multiplied in so great a degree, and such nun> 

 bers brought into view, which were invisible to the naked 

 eye. In Jupiter he perceived a large disk, approaching 

 in size to the moon. Near it, as he saw it for the first 

 time, were three luminous points ranged in a straight line, 

 two of them on one side of the planet, and one on the 

 other. This occasioned no surprise, for they might be 

 small stars not visible to the naked eye, such as he had 

 already discovered in great numbers. By observing them, 

 however, night after night, he found these small stars to be 

 four in number, and to be moons or satellites, accompany- 

 ing Jupiter, and revolving round him, as the moon revolves 

 round the earth. 



The eclipses of these satellites, their conjunctions with 

 the planet, their disappearance behind his disk, their 

 periodical revolutions, and the very problem of distinguish- 



