592 
Proceedings of the Royal Irish Academy, 
longer than that given in the Catalogue. Some recent measures 
are : — 
1886-5695 
269°-6 
0".71, Hall. 
1886-5722 
276 
•6 
0 -66, „ 
1886-6023 
274 
•3 
: 0 -58, „ 
1886-7064 
264 
•9 
0 -67, „ 
1886-739 
271 
•0 
Less than V'? Pollock. 
1888-62 
257 
•4 
: 0 -70, Burnham (6 nights.) 
1888-707 
260 
•2 
: 0 -68, Leavenworth. 
1889-41 
255 
•1 
: 0 -81, Eurnham(^.i\^.), 2957. 
47. y Coronas Australis. The period of this remarkable binary is 
certainly longer than that found by Downing and Sehiaparelli, and 
apparently somewhat longer than that given by my orbit. Powell's 
elements are perhaps the best hitherto published. These show, 
however, the distance at present diminishing, whereas recent measures 
seem to show that it is on the increase. Some recent measures are : — 
1886-615 
200°-59 
I" 
•45, Pollock. 
1887-714 
196 
•7 
1 
•68, Tebbutt (3 nights). 
1887-767 
194 
•7 
„ (1 night). 
1888-307 
192 
•4 
1 
'59 ,, 
1888-637 
: 187 
•8 
1 
•77 „ (4 nights). 
1888-707 
188 
•0 . 
Leavenworth. 
1888-809 
: 191 
•9 
2 
•30, Tebbutt (2 nights). 
1888-843 
: 185 
•4 
- n (4 nights). 
1889-41 
: 185 
•4 
1 
•79, Burnham {A.K, 2957) 
Mr. Tebbutt' s measures were communicated to me by private 
letter. In his letter he says: "The measures of position angle are 
much more easily made than in former years, as the distance between 
the components has sensibly increased." If this be so, a really good 
orbit of this interesting binary has yet to be computed. 
48. 8 Cygni = IS 2579. A difficult double star to measure, owing 
to the great inequality in the brightness of the components. My 
orbit represents all the measures of position angle fairly well, but 
gives the distance apparently somewhat too large at the earlier epochs. 
Duner suggested that Sir "W. Herschei's measure in 1783 of 18° 21' 
n.f. should read 18° 21' s.f. ; but, according to Sadler, the diagram 
in Herschei's MSS. lends no support to this hypothesis ( Olservatory, 
