154 Mr. South’s observations of the apparent distances 
No. DXCIX. R. A. 9 h iS m ; Decl. 7 0 1' N. 
Struve, 341 ; Hist. Gael. 273. 
Double ; equal ; each of the 10th magnitude. 
Passy ; January 17, 1825 ; Seven-feet Equatorial. 
Distance =: 3"*78o | 5 Obs. | Diff. — o".g^ 7. Excessively difficult. 
Passy ; February 5, 1825 ; Seven-feet Equatorial. 
9 1 and 10th magnitudes. 
Position =58° 55 ' np 
Distance = 3".45o 
5 Obs. 
5 Obs. 
Diff! = 0" .697 } Extreme h difficult. 
Passy ; March 2, 1285 ; Seven-feet Equatorial. 
9th and 9| magnitudes. 
Position ~ 56° 29' np 
Distance = 3".25 1 
5 Obs. 
5 Obs. 
Diff. = 2 0 42' } 
Diff. zz o".336 5 
Very difficult. 
Passy ; March 26, 1825 ; Seven-feet Equatorial. 
Equal; each of the 10th magnitude. 
Position zz. 5 7 ° 38' np or sf 
Distance zz 3 "-572 
Diff! = \ Extremel y difficult. 
5 Obs. 
5 Obs. 
Mean Result. 
Position 57 0 4i # np or sf {is Obs.); Distance 3". 51 3 (20 Obs.) ; 
Epoch 1825.13. 
No. DC. R. A. 9 h 19“ ; Decl. 9 0 50' N. 
Leonis ; Struve, 342 ; I. 26. 
Double ; large, white ; small, pale blue. 
Royal Observatory, Paris ; March 15, 1825; Eleven-feet Achro- 
matic by Lerebours, having an object-glass of 8.4 English 
inches clear aperture. 
With a power of 420 the small star is separated half a diameter of the large star ; 
with 560 three-fourths of a diameter ; with each power the stars are admirably de- 
fined, and as round as possible : had we any micrometrical apparatus, measures of 
position and distance might be gotten with the greatest facility. Mons. Bouvard 
present. Night favourable. 
Whether the Seven-feet Equatorial will enable me to measure this close double 
star I do not know ; the highest power that can be applied to its present micrometer 
is 273, which is certainly inadequate to show the star double .* 
* By a letter from Mr. Herschel, dated May 14, 1825, I find that Mr. Struve 
has measured this star with his telescope of 9 inches aperture, and 14 feet focal 
length, made by Fraunhofer. 
