. G. W. Struve, Director of the observatory at Dorpat, 
an able and excellent astro onomer, has turned to an impor- 
tant account, the superiority of this new Instrument, in a 
more extended and accurate examination of double stars 
than has been effected by ane preceding astronomer. The 
following are poate from an analysis of his shpeet: on this 
subject by A. Gautie 
The new sane executed in England and at at Dorpat, 
already surpass in precision those of the great ast 
to whom we owe the discovery of Uranus, on account of the 
perfection of micrometers. But the achromatic telescopes, 
hitherto employed have been eeitty inferior, in their optical 
powers, to the ene | cP hata of Herschel. A. tele: 
scope, therefore whic bear a comparison with them, 
in those relations, and shiigh had a decided a aI in 
scope of ee cee, of a certain 
prighthoss, is that portion of the sky, visible to me, in order 
to ascertain which among them is double. I entertained 
the hope of obtaining more positive knowledge on the man- 
ner of distinguishing stars physically and optically double, 
in order to be able to deduce some general views of the 
ane an which these stars are distributed over the celes- 
tial vau 
It is ay under the equator that the Me sky can ts 
|, by the earth’s rotation, while a pole, 
half is visible. In the latitude of Dorpat 121° of ihe 
sky can be seen, viz. from the pole to 313° south of thee equa- 
tor. But the southern stars rise too little above the horizon, 
to be on ex xamined ev it the most powerful i ta of 
the pole, or 15° south of the equator. In this space the 
— stars = still 162° above the horizon at their meri- 
di divided this interval into twelve zones, 
scbonling to ‘the elas from the celestial poles and made 
