210 



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



21 X rfR = — 67".20 

 K = 8.8831 



</b = _3".20 

 dfi = — 0.360 



The discordances in the separate values of d/x have obviously no relation to 

 the zenith distance, or the time of year, and may therefore be regarded as 

 casual. 



If we combine them according to the method already assigned, we obtain, 



Hence 



dfx = 



2305.4273 

 10225.547 



= — 0.2255. 



