THE GENERAL PERTURBATIONS OF THE MINOR PLANETS. 173 
Then from 
rab } 7 : y er, i zg —-L Oz ae Z 
tg a et nme Mere tg — 24% 47 ang = ! ea Sarr 
7 a + 0% + X y +oz + Y z+ oa + X 
ee ee Pape Sed 
sin 6 
’ 
we have, giving also the observed place for the purpose of comparison, 
a, = 340° 31’ 11.4 6: = — 223’ 23" 1 log A = 0.149514. 
a, = 340 33 49.1 d= —2 2 25.4 
where the subscript c designates the computed, and the subscript 0 the observed place. 
Both observed and computed places are already referred to the mean equinox of 
1894.0. If the observed position were the apparent place we should have to reduce 
the computed also to apparent place by means of the formule 
Aa =f+gsin(@+a)tyd 
MS = g cos (G + a), 
the quantities f, y, and G' being taken from the ephemeris for the year and date. 
If the observed position has not been corrected for parallax we refer it to the cen- 
tre of the Harth by means of the formulee 
Riess zpcosg’ sin (a — 4) 
ip A “cos 0 
ig 9’ 
oy = = 
IY cos (4 — @) 
Tae =p sin g’ sin (y — 9) 
4 : sin 7 
where 
a is the right ascension, § the declination, A the distance of the planet from the 
Earth, ~’ the geocentric latitude of the place of observation, 6 the siderial time of 
