and on Astronomical Refractions. 

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

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

 + [1-2501754] e+ [0-7409070] e n + &c.} 



[9-0139814] <p 



tan <t = r i e = tan . 



cos v 2 



501 



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 Tabula Regiomontance (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. 



Tables of Mean Refractions. 

 Bar. 30 inch. Therm., Fahr., 50. 



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



