138 Corrections in Right Ascension of [Feb. 



Mean RA of a Lyra Jan. 1821 = 18 h 30' 52-92" 



Correction for Nov. 27 = + 0-68 



Apparent right ascension =18 30 53-60 



Observed right ascension =18 30 46-33 



Clock's error = - 7-27 



Correction for North Polar Distance. 

 Equation for refraction. 



Greenwich observ. 1812, p. 251, log. mean refraction. = 1-1 1261 

 1811, p. VI. + log. of bar. 29-54, 

 and therm. 46° = 000347 



Log. of true refraction = 1-11608 



True refraction = 13 - 05". 



Equation for Aberration. 



Sun's longitude by Nautical Almanac for Nov. 27 a* 8 s 4° 58' 

 Gr. obs. 1813, p. 260, column a Lyra to be added 6 



Sun's long, at the time of the transit of a Lyra. = 8 5 4 

 Annual number for aberration obs. 1812, p. 251 =6 5 26 



Diff. taken so that it may be less than 6 signs . . = 1 29 38 



Log. cosine = 9-7037 



Gr. obs. 1812, p. 251 + log. max. of aberration. = 1-2523 



Los:, of aberration = 0-9560 



Aberration = — 9-04". The sign is negative, because the 

 difference between the sun's longitude and the annual number for 

 aberration is less than 3 signs. This sign is to be applied to 

 reduce the mean N. P. D. to the apparent. 



Equation for Lunar Nutation. 



Right ascension of a Lyra in space = 9 s 7° 44' 



Longitude of the moon's node = 10 29 35 



Right ascension — long, moon's node = 10 8 9 



Right ascension + long, moon's node = 8 7 19 



Greenw. obs. /8-34 // sin. (AR - long. ) s node) = — 6-56" 

 1812, p. 340. "t 1-20 sin. (AR + long, y node) = - 1-10 



Lunar nutation = — 7-66". This sign is to be applied to 

 reduce the apparent to the mean N. P. D. 



Equation for Solar Nutation. 



Gr. obs. 1813, p. 260, col. a Lyra equation for Nov. 26= -0-22" 



Dec. 6= -0-37 



