British Association. 303 
but it was not: bounded by a regular outline, for there were several 
streamers and also curved rays, which were observed and depicted by 
several observers. Mr Bonomi observed the planets Venus and Jupiter, 
close to the obscured sun, shining with great brilliancy. Under no other 
conditions could these planets be viewed so close to the sun; for in what- 
ever manner the sun might be shut off from view, the atmospheric illu- 
mination would drown these planets in light. Mr Galton’s careful draw- 
ing presented several strange horns of light, supported in part by Mr 
Murray’s.. Mr Weiler’s presented strange appearances, which it was 
difficult to reconcile with the others. M. Plantamour of Geneva, who 
made his observations near the eastern coast of Spain, made three succes- 
sive drawings of the corona during the eclipse. The appearances de- 
picted led the speaker to think that they could only be accounted for on 
the supposition that an atmosphere capable of reflecting light extended 
nearly from the earth to the moon. It was clear they could not be pro- 
duced by our atmosphere. 
He would show experimentally that there were means of detecting the 
difference between reflected and non-reflected light; for this purpose he 
would, with Mr Ladd’s assistance, throw a beam of light on to the screen 
by means of the voltaic lamp; then, as he interposed a doubly-refracting 
prism, the beam would be divided into two beams, one of which would 
revolve round the other without alteration of intensity as he caused the 
prism to rotate. He then would interpose an unsilvered glass reflector 
in the path of the ray, and again place the doubly-refracting prism in 
the path of the ray. On rotating the prism, the two beams of light not 
only revolved the one round the other, but each became alternately ob- 
secured, thus proving that there is a difference between ordinary light and 
reflected light; the reflected light being what is termed polarised. By 
ascertaining, therefore, if the light of the corona were polarised, it could 
be ascertained with great probability whether it came direct to the eye 
or whether it had been bent by some reflecting medium. An English 
observer had proved beyond doubt that the light of the corona was po- 
larised, and a foreign observer, M. Prazmowski, had even gone further, 
and had shown that the position of the plane of polarisation passed , 
through the sun, the corona, and the eye of the observer. When this 
was ascertained, it went a long way towards proving that the light of the 
corona was reflected by something like an atmosphere, or at all events a 
medium capable of reflecting light intermediate between the earth and 
the moon. Was there an atmosphere extending from the earth to the 
moon? ‘The speaker stated that he knew not; but he knew of no other 
hypothesis which would account for the appearances presented by the 
corona. 
The Astronomer-Royal now returned to the red prominences, which he 
stated were seen in great beauty during the eclipse of 1860. As he had 
stated in the early part of his lecture, the question had been raised 
whether they belonged to the sun or tothe moon. By means of the 
moving model, he showed that if they belonged to the moon they would 
follow her as she moved onward; but if they belonged to the sun, those 
on the left would be shortened and those on the right lengthened as the 
moon moved from right to left; as they were actually found so to do, it 
was a strong prima facie argument that they belonged to the sun. M. 
Faye had also pointed out the following fact. Suppose there was a pro- 
minence on the top of the sun at the commencement of the eclipse, it was 
evident that it must be at that moment to the left of the moon’s centre ; 
at the middle of the eclipse it would be just over the centre, and on the 
right of the centre at the end of the eclipse. It was not at all probable, 
if the prominence were an illusion resulting from the sun’s light shining 
