390 Proceedings of the Royal Irish Academxj. 



No. 589. /3 Ctgni.— 3-4 Sufi ; 3 TJlugli Beigh, Tyclio Bralie, and 

 Hevelius ; 3^ Lalande ; 3-33 Sir J. Herschel {Cape Ohs., p. 440); 

 3 m. Heis ; 3-02 Pritchard (1882-455). Klein states that from obser- 

 vations in 1862 and 1863 lie found variation from 3*3 to 3'9 m. "Webb 

 also suspects variation. Espin thinks that /3 probably belongs to a dis- 

 tinct class of variables, like 63 Cygni, and that its period may be one of 

 several years. Sir "W. Herschel gives the sequences 53 (e), 6 (/3), 

 18 (S) 18 ; 6 53 T 6 and 6 — , 14 Lyr^. 2-99 and 3-2 H.P. 



ISTo. 590. D.M. 17°, 3997.— JS^ot given by Lalande or Harding. 

 Bated 6, 6 and 6-5 by d'Agelet, I783,"july 26, 27, and 29; but only 

 9-4 m. in the Durchnusterimg [Nature, December 22, 1881). 



1^0. 591. jj. AatrrL^. — 6 m. Sufi ; 4^ Lalande ; 5-4 Argelander and 

 Heis; 4-4 Johnson; 4-8 DM ; 4 m Franks, August 29, 1877. Six W. 

 Herschel gives the sequences 41 (t) - 38 {jx). M (o-) 38, 32 (v) 38"; 

 59 (^) and 67 (p) ; 38. 5-06 Pritchard (1882-586). Dr. Gould sayS 

 it "has shown marked indications of variability both at Albany and 

 Cordoba" {U. A., p. 323). 



'No. 592. t Aqijil^. — This has been suspected of variation for some 

 years. It was rated 4-5 by Sufi ; 3|-, 4 by Lalande ; 4^, 6 by 

 d'Agelet ; 5 m. Harding and Piazzi ; 4-2 Argelander ; 4-5 Heis, and 

 4-6 by Gould. Sir W. Herschel found rj - l- /x and t - v and t " 71 ; 

 4-52 Pritchard (1882*586). Dr. Gould says the Cordoba observations 

 " give reason to suspect some fluctuations" {W. A., p. 324). My ob- 

 servations are : — August 1875, 4^m. — brighter than v ; October 1876, 

 brighter than v, but slightly less than 12 Aquilas ; August 4, 1877, 

 same as last; September 23, 1879, t considerably brighter than v, 

 nearly 1 magnitude; September 18, 1881, i considerably brighter 

 than V. 3-89 H.P. 



iSTo. 593. STiiir7E 2545 Aquil^ = Lalande 37207. — A double star, 

 6-2, 8-1 : 318°-5 : 3"-5. A third star 170°± : 20", discovered by Mit- 

 chell in 1846, was rated 11 m. by Mitchell and Dawes, but only 

 15 m. by Knott. 



'No. 594. a Dkaconis. — 5-4 Sufi ; 5-6 Argelander and Heis ; 4 m. 

 Groombridge. Sir W. Herschel gives tt - cr - , 55 and p, a. 5 m. 

 Franks, September 11, 1877 {private letter). 4-74 H.P. 



December 13, 1876, about equal to r Draconis. 



June 12, 1877, distinctly less than r, and about = i; Draconis. 



April 9, 1883. cr three steps less than r, but two steps brighter 

 than V, or magnitude 4-9. 



March 4, 1884. o- one step less than t, cr 4-7. 



April 2, 1884. o- a mean between r and v, or 4-8. 



No. 595. 6728 B.A.C. Cygni.— 7 m. Lalande (37313). Not in 

 Seis' Catalogue; 6|-m. Pranks, 1877. 



