458 PHILOSOPHICAL TRANSACTIONS. [ANNO 1783. 



At 7 h. between the 3d and 4th magnitude ; not quite so bright as p Trianguli, nearly equal to £ 

 Persei, and a little brighter than j Persei. 



At 7s h. about equal to f Persei, and nearly of the 4th magnitude. 



At 8 h. rather a little less bright than f Persei ; sky unfavourable. 



x\t Si h. between the 3d and 4th magnitude ; rather brighter than <J*and f Persei. 



At 9 h. certainly brighter than ^Persei, and of the 3d magnitude. 



At 9 k b. of the same brightness as s Persei ; but the sky was not favourable. 



At 10 h. brighter than 1 Persei. 



At 10j h. brighter than at 10 h. and of between the 2d and 3d magnitude. 



At 1 1 1 h. very bright ; and now it seems at its usual magnitude. 



Feb. 9. — At 6| h. nearly equal to /3 Arietis. 



Feb. 23. — At 10| h it was brighter than at 9 J h. when I observed it at its usual brightness ; now of' 

 the 3d magnitude, rather brighter than 1 and £ Persei. 



At 1 1 h. about the same brightness as £ and £ Persei. 



At 12 h. between the 3d and 4th magnitude ; not so bright as t and Z, Persei, a little brighter than 

 s Persei, and a little less than ^ Persei. 



Feb. 2r>. — At 6^ h. between the 2d and 3d magnitude ; rather less bright than « Cassiopeae. 



At 9.3 h. little less bright than £ Persei, and of the 4th magnitude. 



At lOh. nearly between 3d and 4th magnitude; a little brighter than f Persei, and a little les« 

 bright than i Persei. 



March 1. — At 8| h. the 3d magnitude ; a little brighter than 1 and £ Persei. 



At 8f h. brighter than at 8i h. 



At 9\ h. between the 2d and 3d magnitude ; a little less bright than * Cassiopeae. 



At 10 h. I believe it now at its usual brightness. 



March 21. — At J\ h. between the 3d and 4th magnitude ; not so bright as J* Persei, but brighter 

 than e, Persei. 



At 8 h. rather a little brighter than » Persei, and sometimes equal to it. 



At 85 h. the 4th magnitude ; equal to f Persei : or a very little brighter. 



At 9 h. rather a little brighter than { Persei. 



At 10 h. about the 3d magnitude ; equal to £and t Persei, but rather a little brighter. 



At 10g h. brighter than £ and 1 Persei. 



At 1 1 h. much brighter than £ and t Persei ; rather between the 2d and 3d magnitude. 



April 10. — At 8h. the 3d magnitude, and rather brighter than t Persei. 



At 85 h. nearly equal to 1 Persei, though rather a little brighter. 



At 9h. rather less bright than 1 Persei, but brighter than ^ Persei. 



At 9^ h. rather less bright than ^ Persei, and between the 3d and 4th magnitude. 



At 9 J h. about the 4th magnitude ; not so bright as ^Persei, but brighter than f Persei. 



At 10 h. rather less than at 9| h. ; believe it now very near its least brightness. 



April 13. — At 8 h. it was between the 3d and 4th magnitude ; brighter than £ Persei, but not so 

 bright as ^ Persei. 



At 8 2 h. rather brighter than J 1 Persei, and not so bright as t Persei. 



At 9 h. rather brighter than e Persei. It was too low to observe its farther variation. 



May 3. — At 9i h. between the 3d and 4th magnitude ; somewhat brighter than f Persei. 



From a comparison of all the particulars in the above observations it appears, 

 first, that this star changes from the 2d to about the 4th magnitude in nearly 3-J- 

 hours, and thence to the 2d magnitude again in the same space of time ; so that 

 the whole duration of this singular variation is only about 7 hours. And, 2dly, it 



