416 HISTORY OF FORMAL ASTRONOMY 



same succession of phases which the moon exhibits 

 in the course of a month. This he expressed by a 

 Latin verse : 



Cynthiae figuras aemulatur mater amorum : 



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 betrayed 

 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 of that 

 theory had endeavoured to account for this, by 

 supposing that the rays of the sun passed freely 

 through the body of the planet; and Galileo takes 

 occasion to praise him for not being deterred from 

 adopting the system which, on the whole, appeared 

 to agree best with the phenomena, by meeting with 

 some appearances which it did not enable him to 

 explain 9 . Yet while the fate of the theory was yet 

 undecided, this could not but be looked upon as a 

 weak point in its defences. 



The objection, in another form also, was embar- 

 rassing alike to the Ptolemaic and Copernican sys- 

 tems. Why, it was asked, did not Venus appear 

 four times as large when near her perigee, as when 

 near her apogee? The author of the epistle pre- 

 9 L. U. K. Life of Galileo, p. 35. 



