125 
elements, “ which represent seven maxima observed in the 
course of three years, with reference to Piazzi’s estimations of 
magnitude in \ugust, 1803,” viz 
Period — 138 -6 days. 
Epoch = 1860, Nov. 6. 
Having observed this star with more or less regularity 
during the past four years, it occurred to me that it would not 
be uninteresting to compare the elements resulting from a 
discussion of my own observations with those which had been 
deduced by Dr. Winnecke. The results of this discussion I 
have now the honour of presenting to the Manchester Literary 
and Philosophical Society. 
Projecting my observations in the usual way, I obtain the 
following dates of maxima and minima, with the correspond- 
ing magnitudes — 
Maxima. 
1861. 
Dec. 
1 
p 
o 
CO 
-8-4 
mag. 
1862. 
Oct. 
5-0- 
-7-8 
1863. 
Nov. 
19-4- 
-7'6 
1864. 
Aug. 
16-3- 
-7-5 
1865. 
Jan. 
7-3- 
-7-7 
May 
25-5- 
-7-8 
Oct. 
5-5- 
-7-5 
Minima. 
1861. Oct. 26 '3 — 1 3 -6 mag. 
1863. Sep. 18-0— 13-2 „ 
1864. June 19'5— 13-2 „ 
Nov. 4-0— 13-1 „ 
1865. Aug. 6-3— 12-8 „ 
Dec. 14-3— 13-7 „ 
Treating the seven observed maxima according to Mr. 
Baxendell’s method, we obtain the following elements : — 
Period = 137'59 days. 
Epoch - 1864, April 4-95. 
Comparing the observed times of maximum with those 
calculated from these elements, and also from those of Dr. 
Winnecke, we obtain the following differences between calcu- 
lation and observation : — 
* The projection of a series of his own observations of this maximum 
obligingly communicated to me by Mr. Baxendell, yields the following results, 
in gratifying accordance with my own : — Date of maximum, 1863, jSTov. 18'9, 
mag. 75. 
/ 
