396 
ME. WAEEBN DE LA EUE ON THE 
a position-angle 86° 26'^, a group of spots, extending on the 18th from 114° 30' to 
121° 30'f, and a double spot X visible on the 14th in position-angle 243° 63' to 245° 34' 
there were none between which and the luminous prominences any connexion could be 
presumed to exist. The group 114° 30' to 121° 30' was surrounded by many faculs ; 
the spots in it underwent considerable changes on the 19th and 20th; the faculas 
extended evidently beyond the visible portion of the sun’s surface on the 18th ; for a 
part which was not in sight on the 18th came into view on the 19th and 20th. Just 
in the neighbourhood of these faculse there was visible in the telescope during the 
totality, a very brilliant sheet of light. On the 18th, besides the group of spots 
suiTounded by faculas just mentioned, and other small spots delineated in the index 
map, Plate XV., there were three conspicuous spots, which I have designated by the 
letters «, 6, c. Spot c was visible on the 14th, but the two others had not yet come 
round; the three spots «, 6, c continued to be visible on the 19th and 20th. 
On the whole, however, no very intimate relation was discoverable between the pro- 
minences and the sun-spots ; and recent photographic researches having convinced me 
that the formation of spots and their changes are among the least frequent of the great 
disturbances always occurring in the solar photospliere, I take this opportunity of stating 
my opinion that future investigations will rather tend to disprove any very close con- 
nexion between them. 
On the 14th, at 4'' 12“* G®’6 Greenwich mean time, the spots visible on the sun’s disk 
were the following: — 
Spot. 
, /3 
Cluster . -< 7 
Ls 
X first nucleus 
X second „ 
Position-angles. 
45 
112 
113 
114 
114 
114 
243 
245 
37 
21 
6 
25 
35 
51 
53 
34 
Distance from the centre in 
a decimal of the radius. 
•3825 
•5548 
•5169 
•4984 
•5811 
•6075 
•8899 
•9078 
The spots a, (3, 7, and £, somewhat changed, were still on the disk on the 18th, but 
I did not notice any spot which could have been brought by rotation into proximity with 
the western limb of the sun, with the exception of X, which was at some httle distance 
in longitude on the hemisphere turned away from the earth. 
Of the group of small spots surrounded by faculaB, visible on the eastern edge of the 
sun on the 18th, the following were selected and measured on photograph No. 6, whose 
epoch is 1*^ 47"^ 43®'6. 
* See in the index map, Plate XY., the prominences E and P. 
t See in the index map, Plate XY., the prominences H and Gr. 
X See in the index map, Plate XY., the prominence L, which, however, was at some distance from the 
position of X. 
