38 i'HILOSOPHICAL TRANSACTIONS. [ANNO 1781. 



Stars. He observed it in an achromatic transit instrument, 3 feet long, and 

 deduced its mean r. a., by comparing it to several stars, having made the neces- 

 sary corrections for aberration and nutation, the result of all being igi° 28' 3S' 7 . 

 Its declination north was 22° 53'4- The diameter of this nebula about 2' of a 

 degree. 



Fill. Double Stars discovered in 1779> ot Frampton-house, Glamorganshire. 



By Nathan. Pigott, Esq., F. R. S., Foreign Member of the Academies of 



Brussels and Caen, and Correspondent of the Royal Academy of Sciences at 



Paris, p. 84. 



Inclosed are the determinations of the places of 3 double stars, which I dis- 

 covered this summer (1779)'- at ^ east I presume they have not been observed 

 before, because I do not find them inserted in Dr. Bradley's catalogue, published 

 in the Nautical Almanac 1773, or in the Connoisance des Terns, or in other cata- 

 logues in my possession, y Delphini indeed, is in M. de la Caille's catalogue; 

 but not as a double star. The instrument he used was not probably powerful 

 enough for that purpose. In the two-feet telescope of my quadrant it appears 

 only as a single star. These stars were observed by me in a three-feet achro- 

 matic telescope of a transit instrument, with an object-glass near 2 inches 

 diameter. The r. a. are nicely determined by several observations, which 

 always agree with each to a fraction of a second in time. The declinations were 

 deduced from the difference of altitudes between the double stars and the known 

 stars to which they were compared. 



September 5, 1 779- 



App. r. a. App. declination. 



307° 21' b" . .«■ Delphini, 3d mag 15° 8' 53"n. 



309 6 3<> . . 2d or brightest of y Delphini 4 15 20 40 n. 



9 J. . diff. r. a. of the 2 stars in y Delphini. 



Note, both the stars in y Delphini have the same, or nearly the same, decli- 

 nation. The 1st is of the 6th, the 2d of the 4th mag. 



September 1Q. 



319 59 27 + /3 Aquarii, 3dmag 6' 31 34 s. 



3 IS 3 21.. preceding double star, 5th mag 7 40 34 s. 



11 — dirt". R. a. between 1st and 2d of the double stars. 



Note, the 1st seemed of the 5th, the 2d of the 7th mag. The 1st is perhaps 

 6" or 8" s. of the following one. 



337 36 55 4- £ Pegasi, 3d mag 9 41 24 n. 



346 53 361. . double star, 8th, 9th mag 3 5() 17 y. 



Note, both the stars of this double star have the same, or nearly the same r. a.; 

 their difference in declination is 15" or perhaps 20". 



