Gore — On Knoivn Variable Stars. 181 



70. IT Htds-3: = LAtAjnoE 20,556 = BiiLin2fGHA]a: 242. — Yariation 

 has been observed in this star by Birmingham, Gould, and Espin. 

 Birmingham's estimates of magnitude, 1873-1876, vary from 4-5 to 

 6'5. The Cordoba determinations range from 4"3 to 6-1 ; and Dr. 

 Gould says, "place its variability beyond all question." It was rated 

 6 m. by HeveKus ; 5^ by Lalande ; 6"5 by Bessel ; 7'5 m. by Lamont ; 

 and 6"5 by Argelander and Heis. According to the Cordoba observa- 

 tions, a Minimum occurred in the first half of 1871. Dr. Gould calls 

 it " intensely orange red." 



71. RTJes^ Majoeis. — The elements found by Schonfeld represent 

 the maxima generally well, and agree with the probable invisibility of 

 the star to Lalande, 1790, March 15. Pogson, who has observed the 

 star in minimum, fixes this 103 days before the maximum, and re- 

 marked {Men. JVot., P.. A. S., December, 1876) that the star rises 

 with astonishing rapidity to maximum, but fades away very slowly. 

 Schmidt observed a maximum (below 7 m.), 1876, June 17, and found 

 the interval, from first visibility (13 mag.) to maximum, 28 days, and 

 from maximum to disappearance, 112 days. Schonfeld calls its colour 

 "rothlich," and Anwers, '^ blassroth." 



72. 7] Argus. — This celebrated star is one of the most remarkable 

 objects in the heavens, varying, as it has done, through all grades of 

 brilliancy, from Sirius to a 7th magnitude star (I) It was observed 

 by Halley as 4 m. in 1677 ; Lacaille, in 1751, rated it 2 m. ; Burchell, 

 1811 to 1815, saw it 4 m. Prom 1822 to 1826, it was 2 m. In 

 1827, it was 1 m., and about equal to a Crucis. It shortly after 

 diminished again to 2 m,, and so remained till the years 1834 to 1837, 

 when Sir J. Herschell, at the Cape of Good Hope, rated it r4 m. 

 Suddenly, in 1838, it rose to a magnitude nearly equal to Canopus. 

 After this it again faded, until 1843, when it was observed by 

 Maclear to be brighter than Canopus, and almost rivalling Sirius in 

 brilliancy. Prom that time its light has gradually diminished. It 

 Avas 1 m. in 1856 (Abbott) ; 2-3 m. in 1858 (Powell) ; 3 m. in 1860 

 (Tebbutt) ; 4-2 m. in 1861 (Abbott) ; 5 m. in 1863 (Ellery) ; 6 m. in 

 1867 (Tebbutt). In 1874, it was observed 6'8 m. at Cordoba, and 

 only 7"4 m. in Xovember, 1878. Schonfeld considers that a regular 

 period is very improbable, although a period of 46 years was suggested 

 by 'Woli, and a period of about 67 years by Loomis. The star is 

 situated in a very remarkable nebula, in which some observers consi- 

 der that remarkable changes have taken place since Sir J. Herschell 

 examined it with his 20-feet reflector at the Cape. The spectroscope 

 shows that the nebula consists of glowing gas, one of the constituents 

 being hydi'ogen. 



73. T Cabins. — Discovered to be variable by Thome at Cordoba, 

 from observations in 1871-1874. The period has not been deter- 

 mined. 



B .1. A. PROC, 8EK. II., VOL. lY. — SCIENCE. 2 A 



