BINARY STAR a CENTAURI. 451 
aphaster on the west, moves again with proportionate slowness, and so is seen there 
for a long period with hardly any sensible alteration of place. The time of revo- 
Jution seems to be as short as 77 years; and LaCaitue and MaskELyNe’s' obser- 
vations, which had before appeared somewhat anomalous, are fully reconciled, as 
belonging to a former revolution; indeed the small star seems to have been al- 
most in precisely the same situation with respect to the large one when observed 
by MaskELYNE in 1761, as it appeared to Str J. HERSCHEL in 1838; and had ob- 
servations been continued for twelve years after MASKELYNE’s time, our know- 
ledge of sidereal astronomy might have been almost a century in advance of its 
present position. 
Captain W. S. Jacob’s Observations of a* and ? Centauri (A.B. 14" 29:5", NPD. 
150° 12’), made at Poonah, Lat. 18° 31’ N., Long. 4 55™ 42° H., with a Five 
Feet Achromatic Telescope. 
Distance 
of the 
Two 
Stars. 
Estimated Remarks. 
Magnitudes. 
Magnifying Power. 
| Weight of Observations. 
Magnifying Power. 


Or 
| 
= Se | Weight of Observations. 
do. 
definition tolerable. 
daylight; dawning. 
daylight; definition tolerable. 
d 
. 
— 
Chl oF © 


good. 
tolerable. 
do. 
do. 
| | 
G9 G9 &9 OD GO CO G9 G2 OD CO Oy OO GO GO O9 OD G9 C9 C9 G9 LD 
do. 
definition tolerable. 
daylight; definition tolerable. 
: do. 
very good. 
do. 
fair. 
excellent. 

| 
| 
i 



do. 
slightly tremulous. 
| 

PEPE EP PRE E EE PE RED A RE ROKRR EP BD | Number of Observations. 
Tl eel ee tc I De ee ee 
| 
| 
NOt ty by © 
Oro or or 

g 
: 
§ 
a 
Zi 
4 
6 
5 
5 
5 
7 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 






