342 MR WILLIAM SWAN ON THE 
anything like concentric rings. Its light was brightest next the moon’s limb, and 
gradually shaded off into darkness at a distance of about half the moon’s diameter. 
The most striking feature in the corona was the appearance of brilliant beams 
of light which shone out in various directions. They were sharply defined, and 
much brighter than the rest of the corona; and, probably owing to their supe- 
rior illumination, they were visible a little beyond its general outline. One 
of these beams (see Plate XII.), I found was situated 28° 35’ to the east of the 
sun’s vertex. It constituted by far the brightest part of the corona, and had a 
sort of conoidal figure. I had not time to ascertain the positions of the other beams ; 
but there was a remarkable one about 35° or 40° to the west of the sun’s vertex, and 
two others which I have ventured to represent in the figure from memory. The 
three latter beams were quite different in form from the first. They resembled 
the narrow sunbeams which shine through broken clouds; or the inverted cone 
of light visible in the dark over a blast-furnace fed by coke. Their sides were 
beautifully rectilinear, apparently converging to the centre of the sun, so that 
their forms were those of very acute cones. In one at least, the light increased in 
brilliancy from the centre towards the sides, as if the cone were hollow; its edges 
appearing brightest owing to the luminous stratum, constituting the hollow cone, 
being there presented to the eye more obliquely, and therefore acting on it with 
a greater depth of lucid matter. 
The first object that attracted my attention on looking at the corona through 
the telescope was a remarkable hook-shaped red prominence (represented in Plate 
XIL., and in Plate XL., figs. 7 and 8) 110° 30’ to the west of the sun’s vertex. The 
next moment I thought there was the trace of a red prominence in the middle of 
the bright beams of light to the east of the sun’s vertex; but in another instant 
my attention was withdrawn from this by the appearance of a second prominence 
a little below the hook-shaped one, and on looking back I saw no farther trace of 
red light to the east of the sun’s vertex. 
As considerable doubt had been expressed whether the red prominences exist 
in the sun or moon, or are only optical phenomena, I was prepared to look for 
faint objects of variable and indistinct appearance, requiring, perhaps, consi- 
derable attention to see them at all. I was therefore agreeably surprised to find 
the prominences objects of perfectly definite outline, and of permanent form so 
long as they continued visible. The hook-shaped prominence, especially, had a 
remarkably smooth, sharp outline, and its rose tint became darker towards the 
edges, suggesting the idea of a convex surface. At the risk of offering what may 
be deemed: a whimsical comparison, | may mention, that, at the moment, it 
seemed to me very like the Eddystone, or Bell Rock lighthouse transferred to the 
sun, with its top beginning to fuse and bend over like a half melted rod of glass. 
The other prominence was of less height, but of greater lateral extent ; and its top 
was deeply serrated, so as to bear a strong resemblance to a chain of peaked 

