50 
POPULAR SCIENCE REVIEW. 
disc of the moon, surrounded by the aureola of a soft, bright 
light, through which shot out, as if from the circumference of 
the moon, straight, massive, silvery rays, seeming distinct and 
separate from each other, to a distance of two or three diame- 
ters of the lunar disc, the whole spectacle showing as upon a 
background of diffused rose-coloured light. . . . The silvery 
rays were longest and most prominent at four points of the 
circumference, two upon the upper and two upon the lower 
portion, apparently equidistant from each other, giving the 
spectacle a quadrilateral shape. The angles of the quadrangle 
were about opposite the north-eastern , north-western , south- 
eastern , and south-western points of the compass . . . . There 
was no motion of the rays.” 
The spectroscope may perhaps afford some information re- 
specting the structure of these beams ; but the faintness of 
their light will render spectroscopic observation very difficult. 
If I were willing to hazard a speculation as to their structure 
and physical cause, I should associate them, I think, with the 
tails of comets, and regard them as phenomena indicating the 
action of some repulsive force exerted by the sun. Sir John 
Herschel has pointed out that we have demonstrative evidence 
of the real existence of repulsive forces exerted by the sun with 
great energy under certain conditions and upon certain forms 
of matter. A source of perplexity exists, however, in the rela- 
tive narrowness of these beams, whose apparent cross-section, as 
delineated by most observers, is far less than the apparent dia- 
meter of the sun. One would thus be led to infer that the 
real seat of these repulsive energies lies far beneath the solar 
photosphere. It is worthy of notice, too, that the beams 
usually appear to extend from the zone of spots ; and one might 
almost infer that the repulsive action is exerted with peculiar 
energy in lines extending from the sun’s centre towards the 
so-called spot-zone. 
It is with reference to such questions as these that the ob- 
servation of the present and future solar eclipses is so full of 
interest. There are problems presented by the corona which 
are as yet not only unsolved, but apparently very far from solu- 
tion. All the energies of our observers need to be directed to- 
wards the mastery of these difficulties ; and therefore it is that, 
as I think, I have been right in urging as earnestly as possible 
that the records of past eclipses should be made to bear fruit 
in the interpretation of all problems which can be in- 
terpreted by means of them, while the opportunities afforded 
by future eclipses, and the skill of those who observe them, 
should be wholly devoted to those more perplexing problems 
which still await even the means of solution. 
The news has just arrived that the Sicilian party will be dis- 
