288 Double-Stars discovered by Alvan G. Clark. 
No. 12. a® Capricorni. (AB=H 608.) 
Herschel IT discovered a 16-magnitude companion to this star 
and entered it in his second catalogue of double stars. Since 
that time it has received but little attention from double-star 
observers. Under favorable conditions a 6-inch refractor will 
show it fairly. The following are all the measures: 
Herschel IT __... -. ar 2 D6" + 1830+ ln 
Pn ee 44-1 6°36 1846°7 18” 
PROIGOR Bg OL inchs te oe 1874°6 20 
Seva oo 150°2 741 1878°5 3n 
In November, 1862, with the 184-inch object glass now at 
the Dearborn Observatory, Mr. Clark found that this minute 
companion was itself a close, equal pair. Professor Young 
was able to see it with the 9-4-inch refractor of me Dartmouth 
College Observatory when observing at Sher Colorado, 
att an altitude of more than 8,000 feet ive Me sea level. 
, to anyone who has seen this minute pair, is a striking 
iteverntion of the importance of getting above the lower atmo- 
sphere. The following are all the measures > 
Holden -_.-.. ..-.. P=57°@ D=1"-72 1874°6 ln 
eens 58°6 1°24 1874°6 In 
moe 65°2 1°14 1875 ln 
| Siecle Alen HS 63°2 oe 1876°7 In 
Sarina 61°2 1°06 1878°5 2n 
No. 13. +t Cygni. 
This fine pair was discovered in October, 1874, with the 
tae object glass manufactured for Mr. L. JM McCormick of 
Chicago. It has already shown a sa angular motion, and is 
caccole tedly a binary system. It has been carefully and 
regularly observed by Baron oo ened The individual 
measures are as follows: 
P=174:8 D=1:06 1874°90 
174°3 1°43 1875°33 
171°0 1°33 187551 
171°5 1°37 1875°67 
168°9 1°26 1875°89 
163°2 1°26 1876°76 
159°8 1°23 1876°82 
157°0 1°47 1877°39 
157°7 1°25 1877743 
1575 1°33 1877°59 
155°8 1°37 1877-70 
155°0 1°21 1877°79 
152°5 115 1877°84 
154°2 1°14 1877°92 
152-9 1:17 1877794 
