Il6 PHILOSOPHICAL TRANSACTIONS. [aNNO 1 660. 



The head of it is in the book described of a colour like that of Jupiter, all 

 along much brighter than that of the former comet, though of a somewhat less 

 magnitude ; having in its middle only one round, but very bright and large, 

 kernel or speck, resplendent like gold, and encompassed with another more 

 dilute and seemingly uniform matter: its tail being at first about 17 deg. and 

 afterwards 20, and sometimes 25 deg. long, and divaricated towards the end, 

 which became narrower and more attenuated as it approached towards the sun. 



He observes, that this star in progress of time became retrograde, whence it 

 came to pass, that in the months of June and July it did not appear again before 

 the rising of the sun, though the sun left it far behind: whereas, if it had pro 

 ceeded toward the eye of Taurus, it would have appeared again in the morning. 



He maintains that this comet was not the same with the former, which he 

 thinks may be demonstrated only by a due delineation of both their courses 

 upon the globe. 



He concludes, 1st, With an intimation of his sense concerning two other co- 

 mets pretended to have been lately seen ; one at Rome, about the girdle of An- 

 dromeda, in the months of February and March, 1664 ; the other in Ger- 

 many, in Capricorn, about Saturn in the head of Sagittary, during the months 

 of September and October, 1665. 2dly, With an advertisement of what he 

 has done in that important work for the advancement of astronomy, and the due 

 restitution of the fixed stars. 



The second part of this book endeavours to justify the author's observations 

 touching the former comet, excepted against by M. Auzout in several parti- 

 culars. 



From all which he pretends to prove that he has not erred in his observation 

 of February 1 8, nor been prepossessed by any hypothesis, nor deluded by any 

 fixed star, as M. Auzout thinks ; but that near the first star of Aries there then 

 appeared a phenomenon most like to that comet that was seen some days be- 

 fore, if compared with the observations made thereof February 12, 13, 14; 

 though he wiH not hitherto positively determine, whether that phenomenon 

 which appeared to him February 18, was indeed that very comet which he saw 

 with his naked eye and observed with his geometrical instruments, the said 

 12, 13, and 14th days of February; or whether it was another; and whether 

 he had lost that comet, which moved towards the second star in Aries : but 

 leaves to the learned world, and particularly to the Royal Society, to judge of 

 this and the other particulars in controversy. 



II. Isaacus Vossius * de Nili et Aliorum Fluminum Origine. 



* Isaac Vossius, bornatLeyden in ]6l8, was a man of considerable talents and learning, and 

 spent a long life, of 7 1 years, in close study. He recdved several honours and emoluments from 



