of a new Variable S/af\ i6a 



further confirmation, compare two of the mofl: di^ant of 

 therrij viz, Sept. 29. 22 h. and Nov. 20. 6 h. which interval i 

 find contains fix periods, each of 12 d. 20 h. =i=: 



I have it in my intention to purfiie the fubje6t further, and 

 when I have got a fufficient number of obfervations, it will 

 be eafy to determine the period with greater exadlnefs, and 

 alfo at the fame time to afcertain the other particulars of the 

 variation with more precifion. In the mean while I wifli that 

 this account may be confidered as being yet imperfe<£l ; but I 

 was induced to fend it -in its prefent ftate, in hopes that other 

 aflronomers may contribute by their obfervations to the eluci-^ 

 Nation of this phiEnomenon. 



As /3 Lyr^ is a quadruple ftar, N^ ^. of Mr. Herschel*s 

 Vth Clafs of Double Stars *, 1 was deiirous to fee if any of 

 the fmall ftars near it would be affe£led by its different changes ; 

 but they feemed not to fuffer any alteration, either when it 

 was at its greateft or at its leaft brightncfs. I attended to this 

 the more particularly becaufe the lots of the ftar's light was 

 very confiderable, and thephaenomenon feemed to be occafionefd 

 by a rotation on the ftar's axis, under a fuppodtion that ther& 

 are feveral large dark fpots upon its body, and that its axis is 

 inclined to the earth's orbit. 



I muft not omit mentioning here that Mr. Herschel, 

 amongft thofe ftars which he fuppofes to have undergone an 

 alteration, reckons (3 or y Lyras ; becaufe he obferved that y was 

 much larger than (3, while Flamsteed marks both of the 

 fame magnitude -f*. It may alfo be added, as fhewing that /j 

 Lyrae varied in former times, that Hevelius, in his Catalogue, 

 differs from Flamsteed, and marks y^Q^ ^he third rnagnltucie, 



* Phil. Tranf. for 1 782, p. 14?. 

 t Phil. Tranf. for 1783, p. 256. 



Y % ■ aiid 



