GREAT REFRACTING TELESCOPE AT ELCHIES, IN MORAYSHIRE. 405 



/3 CYGNI — continued. 



Com- 

 ponents. 



Magni- 

 tude. 



Colour. 





Position. 



Distance. 



Date. 



Authority. 



A 

















B 





•• 





AB 



55 24 (w 40) 



34-554 (w 40) 



1842-88 



Schluter. 



A 

 B 







Orange gold.... \ 

 Azure j 









1844-5 



Sestini, 



A 

 B 







Golden yellow . "1 

 Smalt blue J 









1849-6 





A 



B 









AB 



56 12 (w 8) 



34-10 (lu 5) 



1854-67 



Spec. Hart 



A 

 B 









AB 



55 12(wl2) 



33-872 (w 12) 



1855-84 



E. Luther. 



A 

 B 







Pale yellow 



Blue 









1856-59 



Guajara. 



A 

 B 







Rich yellow 



Brilliant blue 



AB 



55 25 



34-37 



1857-42 



Fletcher. 



A 

 B 







Golden yellow .... 

 Greenish blue 



AB 



55 16 



34-56 



1857-47 



Wrottesley 



A 

 B 



3-0 

 5-0 





AB 



55 20 (ly 20) 



34-383 (w 20) 



1861-76 



Auwers. 



A 

 B 

 C 

 D 



1 

 1, 



3*0 

 7-0 

 5-3 

 5-0 



Yellow (3) 



Bluish green (3) . . 



Blue (3) 



Blue (2) 



AB 55 28(iy2) 

 AC 340 2{wl) 

 AD 33 45(w0-5) 



34-50 (w 1) 



62-03(^0-5) 



108-44 (lu 0-2) 



1862-72 



Elchies. 



In Mag?iitude, B is supposed to be slightly variable. 



In Colou?% there would seem to be yellow pulsations ; at their maximum 

 converting the single yellow of A into golden yellow, and the blue of B into 

 greenish blue, and even bluish green. 



In Position and distance these stars present one of the most remarkable 

 instances ever met with of near conformity between all ages, countries, observers, 

 and instrumental methods. Only once, in the whole series, does the second of 

 "distance" alter; and only once, excepting in the earlier examples when there 

 may be a cosmical reason for it, does the degree of " Position" change ! 

 I In Character, the pair may be a slow binary ; for though the B. A. C. proper 

 motion test has barely sensible effects, yet they are precisely opposite to what 

 , seems to have occurred ; i.e., they should have kept the Position constant, but 

 I .decreased the distance by \" in thirty years ; but in place of that the Position 

 seems sensibly to have increased, in sixty years at least, and the distance to have 

 remained constant. 



