284. Double- Stars discovered by Alvan G. Clark. 
The names and places of the stars are as follows: 
No, Star R. A. 1880. Decl. 1880. Magnitudes 
1_ |Sirius. 65 39™ 53*| —16° 337 nO 
3 TW VIL. List, 7 40 20 | +28 59 BS xccke 
3 |p Hydre. ean. Ot 6 Tt S215 
4° | 23271 12° 20:. 37 + 0 29 74_.10 
5 |46 Virginis. 12 54 25 | — 2 43 | 5-6._8-9 
6 |Arg. (30) 2534.|14 28 45 | +30 21 94._10 
7 |e Corone. 15 62 37 | +27 14 ee 
8 {102 Herculis. 18 8 38 | +20 48 5 ..12-13 
9 yree. 18 54 27 +32 31 3 2.42 
10... |P XTX, 257. 19:39 15 +10 29 74. 74 
1 itte. 19 43 39 | +18 51 6 6 
12 |a? Capricorni. 20 11 24 | —12 55 ees 
13. |r Cygni. 2)310 2 0:4 37: 32 54.. 8 
14 |78 Pegasi. 23 37 57 | +28 42 Dae 
No. 1. Sirius. 
The history of this interesting system is too well known to 
require more than a brief mention. From periodical irregu- 
the place assigned by theory. Once discovered, it was readily 
and measured with the same instruments with which it had 
The companion has been measured every year since 1862, 
and during the latter portion of the time the observations are 
very numerous. The last orbit of the theoretical satellite, 
computed by Auwers, based upon all the available observations 
of proper motion, gives a period of 49-40 years. From these 
elements an ephemeris has been calculated for every second or 
