a Ang 
174 DOOLITTLE—ORRIT OF DOUBLE STAR 2 518. [Aprils, 
Date. p. 6. n. Observer, 
di fe} 
36 1886.09 3.00 112.23 6 Hall. 
37 1886.92 3.01 111.03 8 Tarrant. 
38 1887.14 2.56 109.18 I-4 Schiaparelli. 
39 1888.08 2.26 109.48 2 me 
40 1888, 12 3.04 107.68 5 Hall. 
4! 1888.84. 2.94 106.83 3 Burnham. 
42 1888.87 2,31 105.05 3 Tarrant, 
43 1889.03 2.87 107.59 I-2 Schiaparelli. 
44 1889.12 2.79 103.55" 4 Hall. 
45 1890.73 2.68 99.95 4 Burnham. 
46 1890.98 1.72 99.00 3 Hough. 
47 1891.01 2.62 101.49 2 Schiaparelli. 
48 1891.06 2.65 98.56 5 Hall. 
49 1891.78 2.48 97.38 4 Burnham, 
50 1893.21 2.18 93.8 I Comstock. 
51 1895.89 83.65 O-I Doberck. 
52 1895.91 2.32 87.4 I Collins. 
53 1897.97 2.62 77.22 3 Aitken. 
54 1899.11 2.39 73.6 2 cr 
55 1899.80 2.30 68.35 3 Doolittle. 
56 1900.92 2.40 63.41 2 3 
aT 1903.14 2.34 55-22 4 : 
Notes—(1) Herschel placed the pair in his ‘‘ Class II,’’ which 
indicates that he estimated the distance as between 4” and 8”, 
Otto Struve considers that at this time the distance must have been 
less than 4”, which seems the more probable. No use has been 
made of this measure in the final adjustment. (2) Excessively 
difficult. The angle was estimated roughly as being in the direc- 
tion of the principal star, of which the position angle is 107°. 
The entire unreliability of this measure was first pointed out by 
Burnham in 1894. (3) No trace of duplicity. (14) This is merely 
a rough estimate. Knott used a7™%inch refractor. (51) ‘‘ Nearly 
invisible.’’ (53) and (54) Made with the 12-inch. I have given 
half the theoretical weight to numbers (5), (38) and (43). (57) 
Was not used in the computation; these observations were made 
after the work was completed. 
These observations were corrected for precession, and then plotted 
as above described, and the elements of the true orbit were de- 
rived from them. These elements were the following: 
ee 
— 
rier an 
