200 



The Rev. Dr. Robinson on the Constant of Refraction. 



17 X <^R = — 24".57 

 K = 4.1560 



dvL = ■ 

 dfi = • 



. 1". 44 



• 0". 348 



/3 AurigcB. 

 Nine observations (1837. 675) give 

 * 8 = + 44° 55' 12". 66. 

 Precession = + 1". 132 ; sec var. = — 0". 642 ; proper motion = — 0."019. 



Airy (Greenwich, 36 and 37) . . 11". 40 Argelander 



„ (Cambridge) . . . 12 . 35 Mine . 



11". 00 

 12 ,76 



