66 NOTICES OF THE MEETINGS [May 2, 
change, from the state of a very narrow lune of solar light (the 
contour of the moon being totally invisible,) to the state of an entire 
dark moon surrounded by a ring of faint light, as most curious and 
striking. The progress of the formation of the ring was seen by 
his companion, and by some other persons: it commenced on the 
side of the moon opposite to that at which the sun disappeared. 
In the general decay and disease which seemed to oppress all nature, 
the moon and corona appeared almost like a local disease in that 
part of the sky. In some places, the corona was seen as distinctly 
double; it would appear that the ring which the Lecturer saw 
(whose breadth, by estimate of repeated duplication, he found to be 
about one-eighth part of the moon’s diameter, or four minutes of arc 
nearly) was the inner of the two rings seen by M. Arago and others. 
The texture of the corona appeared in some places as if fibrous, or 
composed of entangled thread; in some places, brushes or feathers 
of light proceeded from it. One photometric estimate of the quantity 
of light in the corona, cited by M. Arago, gave it equal to one- 
seventh part of full moonlight. From a chromatic analysis of its 
light by means of an ordinary prism, it appeared to be deficient in 
green rays. 
The Lecturer characterised the inquiry into the origin and locality 
of this corona as one of the most interesting connected with the 
eclipse. It had been specially indicated by M. Arago (see the 
Annuaire du Bureau des Longitudes, 1842) as a very important sub- 
ject of inquiry whether the corona is concentric with the moon or 
with the sun; but his recommendation had received very limited 
attention. ‘The general tenor of the evidence went to prove that 
the corona belongs to the san. This, however, was not the opinion 
of more ancient writers, who tacitly consider it as the atmosphere 
of the moon. 
But the most remarkable of all the appearances were the red 
mountains or flames apparently projecting from the circumference of 
the moon into the inner ring of the corona, to the height of one mi- 
nute of arc at the smallest estimation, or a much greater height by 
other estimations. It was afterwards discovered that these had been 
seen before by Vassenius, a Swedish astronomer, who observed the 
eclipse of 1733 at Géteborg, (a place very favourable for the approach- 
ing eclipse), and whose account is given in the Philosophical Trans- 
actions, vol. xxxvili. He terms them ‘‘subrubicunde nonnulle 
macule, extra peripheriam disci lunaris conspectee, numero tres aut 
quatuor.” This observation, however, was not known to any of the 
observers in 1842, and all were therefore taken by surprise. Drawings 
were exhibited of these red mountains asseen at Perpignan, Narbonne, 
Vienna, Pavia, Superga, and Lipetsk. It was shown that, by a trace 
still visible on the engraving, the drawing first made at Vienna had 
coincided very exactly with that made at Pavia; that the Narbonne 
observations would be very exactly reconciled with them by suppos- 
ing the error (very likely to occur to unpractised astronomers) of 
ee 
