M. Struve and Prof. Amici's Observations on Double Stars. 889 
Hence the difference of declination of these stars has diminished 
in 7.6 years. 
M. Struve has likewise published his observations on 68 Double 
and Multiple Stars, which we hope to be able to lay before our 
readers in next Number 
•SOV? 
In a subsequent article in Baron Zacb’s Correspondance , he has 
given an account of some observations on Double Stars, made by 
M. Struve with anew micrometer, constructed byM. Frauenhofer 
of Munich. These observations are highly interesting both in 
themselves, and as shewing the great accuracy with which this 
class of observations may be made with good instruments. 
ec Hercules. 
g Hercules. 
95. Hercules. 
Distance. 
Distance. 
Distance, 
1822, Aug. 26. 4" 94 
Aug. 26. 4". 60 
Aug. 27. 6 // »53 
27. 5 .31 
27. 4 .51 
Sept. 20. 6 .55 
31. 5 .14 
31. 4 .15 
— « 
Mean, 5".13 
Mean* 4".42 
Mean, 6" 54 
5. Eagle. 
| Great Bear . 
61 Ophiuchus. 
Distance. 
1822, Aug. 24. 13". 13 
Aug. 31. 14" 79 
Aug. 26. 20". 17 
Sept. 22. 13 .42 
Sept. 2. 14 .69 
Sept. 2. 20 .54 
Mean, 13".27 
Mean, 14". 74 
20. 20 .71 
Mean 20", 47 
15. Eagle. Distance, 
1822, Aug. 24. 31".68 
Sept. 22. 31 .64 
Mean 31<66 
The following are measures of the differences of declination, 
of the double star y AHetisj with the same micrometer. 
1821, Nov. 9, 
9"26 
8 .84? 
8.94 
8.68 
Mean, 8". 93 
Nov. 28. 
9' ,18 
9 .26 
8 .94 
Mean 9 // .13 
Dec. 12. 
9 V .08 
9 .SO 
Mean 9 ,29 
Genera! 
Mean, 
9"0.6 
Difference of declination of the double star 0 of Cancer. 
1822, Feb. 21. Feb. 25. Mar. 19, Mar. 26. a 
4".82. 
5.04. 
Mean 4". 93. 
4 "62, 
5".oo. 
4 .86. 
Mean 4' .93. 
4" 58. 
5 .04. 
Mean 4' / ,8L J 
y 0 
| General 
J- Mean, 
4/485. 
