27S HISTORY OF FORMAL ASTRONOMY. 



and suggested at once the thought that it contained mechanism more 

 various and more vast than had yet been conjectured. And when the 

 system 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 sup- 

 ported the belief of such an arrangement of the planets, by an analogy 

 all but irresistible. It thus, as a writer 9 of our own times has said, 

 " gave the holding turn to the opinions of mankind respecting the 

 Copernican system." We may trace this effect in Bacon, even though 

 he does not assent to the motion of the earth. " We affirm," he says, 10 

 " the sun-following arrangement (solisequium) of Venus and Mercury ; 

 since it has been found by Galileo that Jupiter also has attendants." 



The Nuncius Sidereus contained other discoveries which had tht- 

 same tendency in other ways. The examination of the moon showed, 

 or at least seemed to show, that she was a solid body, with a surface 

 extremely rugged and irregular. This, though perhaps not bearing 

 directly upon the question of the heliocentric theory, was yet a blow 

 to the Aristotelians, who had, in their philosophy, made the moon a 

 bodv of a kind altogether different from this, and had given au abun- 

 dant quantity of reasons for the visible marks on her surface, all pro- 

 ceeding on these preconceived views. Others of his discoveries pro- 

 duced the same effect; for instance, the new stars invisible to the naked 

 eye, and those extraordinary appearances called Nebulas. 



But before the end of the year, Galileo had new information to com- 

 municate, bearing more decidedly on the Copernican controversy. 

 This intelligence was indeed decisive with regard to the motion of 

 Venus about the sun ; for he found that that planet, in the course of 

 her revolution, assumes the same succession of phases which the moon 

 exhibits in the course of a month. This he expressed by a Latin verse : 



Cynthiee figuras .aemulatur mater amoruin : 



The Queen of Love like Cynthia shapes her forms : 



transposing the letters of this line in the published account, according 

 to the practice of the age ; which thus showed the ancient love for 

 combining verbal puzzles with scientific discoveries, while it betrayei 1 

 the newer feeling, of jealousy respecting the priority of discovery of 

 physical facts. 



It had always been a formidable objection to the Copernican theory 

 that this appearance of the planets had not been observed. The author 



» Sir J. Ilerschel. 10 The ma Call, ix. p. 253. 



