(7) 
in the winter of 1896—97 to over 4° and decreasing the following 
winter to somewhat over 2°, now proved to be reduced to 0° in the 
last opposition 1). A total of 16 serviceable measurements after the 
periastronpassage seemed sufficient to venture on a correction of the 
elements of this interesting system. 
The space not allowing me to enumerate here all the separate 
measurements, I must refer to the Ast, Nachr. 3084—85, for the 
observations up to 1890, where Prof. Auwers communicates them 
in extenso. Here and there only do the positions used by me differ 
a little from his on account of assigning slightly different weights 
to the results of the separate nights. Just as Prof. Auwers I had 
formerly been obliged to derive a measurement of Haut in 1888 
from the compilation given by Prof. Burnnam in Monthly Notices lviii 
6 without knowing its source. In the 2nd part issued since then 
of the Observations of double Stars, made at the U. S. Naval Obser- 
vatory by AsapH Hatt, Ì find: 1888.248 p = 23°27; s=5'777, 
with remarks as faint, very faint, extremely faint for the separate 
nights. Not being able however to make the angle of position agree 
in any way with the surrounding measurements I have now also 
excluded this measurement. Farthermore Mr. Haut gives a few 
yearly means differing slightly from his previous statements in M. N., 
A, N., and A. J. I considered the last values the best and have 
modified the previous data accordingly. 
The communication of the separate measurements after the peri- 
astron-passage would demand too much space; L therefore restrict 
myself to the following table of the mean numbers for each observer 2). 
The observed angles of position have already all been reduced to 
the meridian of 1900.0 by applying the correction for precession. 
1) It may be mentioned here that the orbit of Prof. Auwers leaves the following 
deviations (Ods. — Comp.) : + 159.24; + 13°.87;-+.11°53. ‘These are indeed greater, 
but they also indicate that the assumed time of revolution is nearer the truth than mine. 
2) As a rule all the observations of one and the same observer during one opposition 
are contracted into a single mean. With the relatively great changes in 7 however, 
the motion of the angle in this part of the orbit is far from regular and the 2nd 
differences (with an ephemeris from year to year) amount to several degrees. I have 
therefore not dared to join into means the observations 5 and 11, 7 and 12, 13 and 
15, 14 and 16; in every case the difference in time amounts to half a year nearly. 
(In passing the proofs through the press). In M. N. lviii 6 is still communicated 
the following measurement of Lewis at Greenwich with the 28-inch: 189%.214, 6= 
179°2, r=4/68 (1 night). This had been overlooked but would have received at 
all events the weight 0, the deviation in the angle of position amounting almost to 
10°, 7. e to more than 0’5 in are of the great circle (according to elements IL; 
Ab=+9°93; Ar= + 0'53). 
