ae 
OBSERVATORY AT WEST POINT. 201 
TO FIND ft AND v. 
Denote by A, the right ascension of a star, and by 7’ the sidereal time of observation, 
then will 
s=ti—AR,, 
and eq. (1), for the same star observed in quick succession in direct and reversed posi- 
tion, gives 
s=(U'—AM) = o'+do+x sin (p—s) tan J’+u tan 0+ sec &. 
s' = (t'"—M) =0"+do +A sin (o>—s) tan J’—uy tan d’—y sec 3. 
Taking the first from the second and reducing, we have 
(t”’—t')—(o""—o') = —2 uw tan --2yseo. . . . . . (11) 
and for a second star differing considerably from the first in declination, 
(t,—t,)-—(0,,—~0,) =—2 wtan #'’—2ysecd".. . . . . (12) 
in which s and » are the only unknown quantities. 
EXAMPLE. 
To illustrate, I take the stars observed on the 3d of April. 
Object. [Face] cutonometer.| intervai,| Interval. | Hour Circle. | Hin Atle} Dec. Circle, | Refr. “| TDettination. [rue Declination, 
(ij—t) (0 oe 9) 
y Urew Majoris,| N. | 4°41™42s, 5°56™16s, 54°33'45”". 
8™00*,; 8™01°.31 8™05s, —40’.89) 54°83/04".1 | 54°88/52".48 
S.| 449 42. 18 04 21. 54 3845. 
|e Hydra. W.| 735 O1 .5 6 27.05) 17 57 10. 7 0100. 
| 6 26. 6 38. —39 89) 700385 .1] 6 5916 3 
| E. | 7 41 27.5 6 03 48. 70130. 
| 
| Urse Majoris.| B.| 818 14. 5 56 51. 52 2430. 
| me es 10 26.) 10 27.7 10 12. 11 .35) 562 2423 .5 | 52 2318 .3 
.|8 28 40. 18 07 03. 52 2355 . = 
The data furnished by this table in equations (9) and (10), give 
A= N(48.4)? + (72) w= 86175 = 1'26”.-756. 
Tan 9 = a Tan 33°54’35", 
= 33°54/35". 
and in equations (11), (12), give, regarding face west as the reversed position, 
0.24 u + 2,02 y = —11° 
2.60 w+ 3.28 »y = — 15° 
VOL. IX.—54 
