PHENOMENA OF GROUPS OF SOLAR SPOTS. 193 



September 27, g^h. a.m. The large spot of J has 

 rotated still further, and a small spot which was in a pro- 

 jecting part of its penumbra n p is now quite detached, 

 with a bright line between. The following large spot 

 seems to have changed little, if at all, ^ is now a fine 

 double group ; principal spot 6th mag. 



September 29, gh. a.m. Preceding spot of J presents 

 no fresh indication of rotation. Four 8| or gth mag. spots, 

 which I regard as two new groups o and cf), have broken 

 out in the space within the groups M, N, O, and P ; pre- 

 ceding spots in each a little larger than following. 



October 1, 4A. p.m. Many new spots in o and (f), and 

 they now form one compound group, in which, however, 

 there is a tendency to the binary arrangement. 



October 3, 8^. a.m. The compound group (o + cp) has 

 five 8^^ mag. spots; the rest are gth and 10th mag. It 

 has a very irregular form. 



October 5, 8|/j. a.m. Many of the spots in following 

 part of the compound group (o + (p) have united into one^ 

 which is a gth or 6th mag. in size. 



October 6, 4^^. p.m. The compound group (0 + ^) 

 now consists of a gtk mag. spot with a very large penum- 

 bra, preceded by several smaller spots. 



There is a common, and, as it appears to me, very sig- 

 nificant feature of binary groups which is often alluded to 

 in the journal, and I will therefore add an observation 

 having reference to it. 



September 16, 1859, 8^^. a.m. The following sub- 

 groups of D, F, G, and H contain more spots and extend 

 over a larger area than the preceding ; but the principal 

 spots in the preceding sub-groups are larger than those in 

 the following. 



SER. III. VOL. I. c c 



