206 Proceedings of the Royal Irish Academy. 



183. S AQTJAEn. — Elements derived by Schonfeld from observa- 

 tions of 4 maxima and 18 complete periods give the period 280-4 days, 

 with deviations up to 10 days. Correcting the period with reference 

 to an observation by Lalande, 1798, Oct. 22, this deviation would be 

 increased to 18 days at the maximum of 1873, Oct. 8th. 



184. /? Pegasi. — Variation irregular, according to Schcinfeld, and 

 often for a long time scarcely perceptible. Argelander found as an 

 approximation — 



Ep. E. Min. 1851. 9. 23-3, Max. 1851. 10. 14-6 + 41^-079 E. 



But Schonfeld says this is not confirmed by observation, the period 

 being more probably an irregular one between the limits of 30 and 

 50 days. 



185. E, Pegasi. — According to Schonfeld, the observations cannot 

 be represented by a constant period. The Elements 



Max. Ep. E. = 1858. 3. 17-1 + 379^-48 E 



would, however, well represent the observations from 1848 to 1867. 

 The period given in the Catalogue is deduced by Schonfeld from 9 

 certain maxima and 21 complete periods, but shows a fault up to 30 

 dayS; and does not agree with earlier observations. 



186. S Pegasi. — Period derived by Schonfeld from observations in 

 1872 and 1873, and a maximum, 1874, middle of July. He gives the 

 approximate Elements. . — 



Max. Ep. E. = 1873. 9. 4 + 316^- E. 



187. R AaiJAEn. — Erom the earlier observations of the star Schon- 

 feld derives a period of 392 days ; but from Argelander's observa- 

 tions and his own, he finds 391 days, the period having probably 

 diminished. He thinks, however, that the period may have even 

 changed to 380 days or 405 days ; but neither of these will agree with 

 Argelander's observations, 1843-1848. He suggests that Argelander's 

 observed maxima, in these years, may have been only secondary ; and 

 his own observations show signs of such secondary maxima. Schonfeld 

 calls its colour " sehr roth." 



The period of this star has lately been discussed by S. C. Chandler, 

 Jun. {Scie?ice Observer, Oct., 1877); and he concludes that "instead 

 of a uniform period, we must assume a variable one, with a mean 

 value of 387 "4 days, which runs through the cycle of its irregularities 



