and on Astronomical Refractions. 

 = sin fl {[3-0541728] e + [2-8051475] e 3 

 + [2-3443834] e 5 + [1-7821564] c 7 

 + [1-2501754] e D + [0*74090?0] e n + &c.} 



501 



tan <p = 



[9-0139814] 

 cos 



e = tan 



1 

 21 



Mr. Russell has calculated a table of refractions from the above 

 formula ; and the following comparative view has been drawn up, 

 with Bessel's table in the Tabidce Rcgiomontance (which may be 

 considered as the result of observations), with the table published 

 annually in the Conn, des Temps, and with Mr. Ivory's table, re- 

 cently published in the Phil. Trans. 1838, p. 224. 



Tables of Mean Refractions. 

 Bar. 30 inch. Therm., Fahr., 50°. 



~ App v 



Zenith 



Mean Refractions. 



App. 

 Zenith 





Calculated. 



Observed. 



Dist. 











Dist. 



Conn, des Temps. 



Ivory. 



New Table*. 



Tab. Reg. 



10 



10-30 



lo'-30 



10-30 



10%) 



o 

 10 



20 



21-26 



21-26 



21-26 



21-26 



20 



30 



33-72 



33-72 



33-72 



33-72 



30 



40 



48-99 



48-99 



48-99 



48-99 



40 



45 



58-36 



58-36 



58-36 



58-36 



45 



50 



69-52 



69-52 



69-51 



69-52 



50 



55 



83-25 



83-25 



83-24 



83-24 



55 



60 



100-86 



100-85 



100-85 



100-85 



60 



65 



124-65 



124-65 



124-63 



124-62 



65 



70 



159-22 



159-16 



159-16 



15911 



70 



75 



214-83 



214-70 



214-68 



214-58 



75 



80 



320-63 



32019 



320-08 



319-88 



80 



81 



354-33 



353-79 



353-64 



353-38 



81 



82 



395-37 



394-68 



394-47 



394-20 



82 



83 



445-87 



445-42 



445-11 



444-86 



83 



84 



511-22 



509-86 



509-34 



509-23 



84 



85 



595-80 



593-96 



59313 



593-38 



85 



85| 



648-34 



646-21 



645-15 



647-10 



85| 



86 



710-07 



707-43 



706-04 



707-15 



86 



86* 



783-07 



779-92 



778-08 



777'36 



86£ 



87 



870-37 



866-76 



864-30 



864-59 



87 



sn- 



975-89 



971-93 



968-84 



972-21 



87i 



88 



11051 



1101-35 



1097*26 



1101-40 



88 



88* 



12650 



1262-6 



1257-66 



1265-5 



881 



89 



1464-9 



1466-8 



1461-49 



1481-8 



89 



89£ 



17164 



1729-5 



1725-70 



1764-9 



891 



90 





2072-6 



2075-4 





90 



* The constitution of the atmosphere is shown by the table in p. 498. 



