STUDY IX. 213 



it*s annual circle, no one of thofe Stars increafes or 

 diminiflies in magnitude witli refpedt to us. 



I fubmit fome farther obfervations, tending to 

 prove, that the Stars have, at lead, motions pecu- 

 liar to themfelves. The ancient Aftronomers have 

 obferved, in the neck of the Whale, a Star which 

 prefented much variety in it's appearances ; fome- 

 times it appeared for three months together, fome- 

 times during a longer interval ; fometimes it's ap- 

 parent magnitude was greater, fometimes fmaller. 

 The time of it's appearances was irregular. The 

 fame Aftronomers report, that they had obferved a 

 new Star in the heart of the Swan, which from time 

 to time difappeared. In the year 1600, it was 

 equal to a Sjar of the hi ft magnitude ; it gradually 

 dirninifhed, and at length difappeared. M. CaJJini 

 perceived it in 1655. It increafed for five years 

 fucceflively ; it then began to decreafe, and re- 

 appeared no more. In 1670 a new Star was ob- 

 ferved near the head of the Swan. Father Anjdniy 

 a Carthufian friar, and feveral other Aftronomers, 

 made the obfervation. It difappeared, and be- 

 came again vifible in 1672. From that period, it 

 was feen no more till 1709, and in 1713 it totally 

 difappeared. 



Thefe examples demonftrate, that the Stars not 

 only have motions, but that they defcribe curves 



p 3 very 



