414 HISTORY OF FORMAL ASTRONOMY. 



astronomers ; which have been observed by Galileo 

 Galilei, &c. &c., by the assistance of a perspective 

 glass lately invented by him ; namely, in the face of 

 the moon, in innumerable fixed stars in the milky- 

 way, in nebulous stars, but especially in four planets 

 which revolve round Jupiter at different intervals 

 and periods with a wonderful celerity; which, 

 hitherto not known to any one, the author has 

 recently been the first to detect, and has decreed to 

 call the Medicean stars" 



The interest this discovery excited was intense : 

 and men were at this period so little habituated to 

 accommodate their convictions on matters of sci- 

 ence to newly-observed facts, that several of " the 

 paper-philosophers," as Galileo termed them, appear 

 to have thought they could get rid of these new 

 objects by writing books against them. The effect 

 which the discovery had upon the reception of the 

 Copernican system was immediately very consider- 

 able. It showed that the real universe was very 

 different from that which ancient philosophers had 

 imagined, and suggested at once the thought that it 

 contained mechanism more various and more vast 

 than had yet been conjectured. And when the sys- 

 tem of the planet Jupiter thus offered to the bodily 

 eye a model or image of the solar system according 

 to the views of Copernicus, it supported the belief 

 of such an arrangement of the planets, by an 

 analogy all but irresistible. It thus, as a writer 7 of 



7 Sir J. HeracheL 



