30 C. H. MoLEOD ON 



belonging to the old cycle, but would seem rather to be a part of the general tendency of 

 the spotted areas to move towards the equator as the period increases towards a maxi- 

 mum. 



The most interesting group of spots, both from its long life and its behaviour, which 

 has appeared during the past year, was first observed as a single spot near the western 

 limb on Aug. *7th, reappearing on the eastern limb very greatly developed (approximate 

 area = 220 millionths of the sun's hemisphere) on August 25th, and after crossing the 

 sun's disc was again observed near the eastern limb on September 24th, and was last 

 seen on October 2nd. The behaviour of this group cannot be better described than in the 

 words of Mr. Maunder, who referring to the group shortly after its second appearance, 

 remarks that as it drew away from the limb, it showed itself greatly enlarged (area of 

 whole group as observed here at the time, reached as high as 400 millionths). Two small 

 spots led the group, then came a confused mass of very small spots, and a large spot with 

 a dark nucleus followed. The small spots in the centre of the group, crystallized out on 

 the succeeding days into a number of well-defined spots, the largest of which exceeded 

 in size all the others put together. Three pairs of nuclei were now in existence, and 

 these, which comprised the two leaders of Aiagust 27th, and the double nuclei of the two 

 principal spots, each showed a remarkable instance of apparent partial rotation. The 

 most distinct case of apparent rotation was furnished by the last spot of the group, in 

 which the northern nucleus moved at a regular rate of about 10" or 11° a day in position- 

 angle, with regard to the southern. The other two examples were not by any means 

 so well marked or so regular, but still the rotation came out there. Perhaps, however, it 

 is scarcely fair to call this movement rotation ; it really seemed to be a well-marked case 

 of the way in which sunspots on the outside of a group are dragged into axial line. Two 

 of the spots turned in position-angle in one direction and one in the opposite direction. 

 Many changes took place in the group, and the two main spots seemed to draw all the 

 little spots into them, a proceeding that is frequently the case in a sunspot group. But, 

 although they exhibited this attraction for all the little spots, the two great spots had a 

 distinct repulsion for each other, and separated at the rate of 1| degree or 9,000 miles a 

 day. Another instance of a long-lived group was one first observed here on November 

 22ud, near the eastern limb as a group of two spots with an area of approximately 75 

 millionths. The group developed rapidly until the 26th, when there were 18 spots 

 extending over 13° of longitude, and the whole spotted area amounted to about 100 mil- 

 lionths. Two days later the length of the group had increased to 15", and the area reached 

 175 millionths, the number of spots decreased and the central group increased in area, 

 amounting at this time to more than half of the total area of the group. Although not 

 a"-ain well observed during this rotation the group would appear to have gradually dimi- 

 nished after this date, the 28th November, when it was nearly in the central meridian, 

 in its first revolution. It reappeared as a very small spot (area 10 millionths or slightly 

 larger than the earth's disc), and experiencing a still further reduction in size was last 

 seen on December 28th when its area was reduced to 5 millionths. 



The following are amongst the most important groups which have appeared during 

 the year : 



