of a new Variable Star» 15^ 



-their change of pofition occaiioned by the earth's diurnal 

 motion, and that particularly In ftars of a great altitude. 



The magnitudes of the liars, to which /3 Lyrse was com- 

 pared during the progrefs of its variation, are as follows. 

 P Cygni and y LyriE of the third magnitude ; f and 5 Herculis 

 of between the fourth and third magnitude ; Herculis is 

 fomething lefs than a ftar of the fourth magnitude; f, ;«, and 

 ^ Lyr« are ftars of between the fourth and fifth magnitude, if 

 not nearer the fifth. The relative brightnefs of thefe ftars. 

 follows the order in which they are fet down. 



OhfervaUons of the bright nefi aiid magnitude of jG Lyn*. 



1784, Sept. 10. At 1 1 h. =^, much lefs than y Lyr:E ; 

 nearly equal to, if not rather brighter than ^, x, and ^ Lyrys, 

 and not fo bright as |, Q, and Herculis ; between the fourth 

 and fifth magnitude. 



Sept. II. At 8| h. nearly the fame as it was lafi: night, if 

 not brighter ; indifferent obfervation. 



Sept. 12. At 8| h. and ph. between the third and fourth 

 magnitude ; lefs than y Lyras, brighter than Q, |, and Her- 

 culis, and much brighter than f, x, and 2 Lyras. Mr. E. 

 Pi GOT T agrees with me nearly. 



Sept. 13, 15, 18, 19, and 20. It was at or near its greateft 

 brightnefs, 



Sept. 23. At 7 1 h. It was nearly equal to ^, x, and I Lyrae, 

 and much lefs than f, ^, and Herculis. 



At io| h. the air being extremely clear, I compared it more 

 attentively to the neighbouring ftars, and found it as follows : 

 rather a little brighter than ^, a little lefs than ^, and rather 



X 2 lefs 



