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POPULAR SCIENCE REVIEW. 
points upon which our knowledge of the sun and its surround- 
ings has been advanced by this particular eclipse. It has been 
rendered tolerably certain that there is around the sun a self- 
luminous shell (the leucosphere), extending upon an average a 
sixth of his diameter beyond the hydrogen atmosphere, the 
principal constituent of which shell is that unascertained 
matter which gives the “ 1474” line ; and that although this shell 
is self-luminous, it yet reflects some light from the brilliant 
strata beneath it. In the second place, it appears probable 
that there is a great extension, irregular in character and with 
a tendency to radiality, of matter which has either self-lumi- 
nosity of the same kind as the leucosphere, though more feeble, 
or that has a special aptitude for reflecting leucospheric light. 
In the third place, it is pretty certain that there is a consider- 
able scattering of all light not intercepted by the moon in and 
by some medium on this side of that body — either our atmo- 
sphere or a cosmical haze. This is as much as can be safely 
said upon the strength of the evidence now before us. More 
may possibly be inferred when a searching examination of the 
complete and detailed observations (which the Astronomer 
Royal has suggested should be made in connection with the 
undigested observations of the 1860 eclipse) is accomplished. 
It is much to be desired that this should be done before the 
time of the next eclipse — the 11th of the coming December — 
as it is not improbable that points of inquiry may be raised 
which that eclipse, from its peculiar circumstances, will afford 
special opportunities for deciding. The shadow will pass over 
the lofty Neilgherry Hills of India, and most valuable observa- 
tions, bearing upon the question of the corona’s atmospheric 
constituent, may be made at the exceptional elevations thus 
accessible.* The duration of totality there will be a few seconds 
over two minutes. In Northern Australia, however, where the 
shadow passes over Arnhem Land, the totality will last four 
minutes, and we hear with satisfaction that one observer, M. 
Bulard, of the Algiers observatory, intends to station himself 
there, most probably with photographic apparatus. And we 
may well rely upon the energy of the Australian astronomers to 
make the most of the occasion. 
* Considering how the balloon has been pressed into scientific service, 
one cannot help wishing that a high balloon view of a total eclipse could be 
obtained ; but there is no chance of an opportunity for such a view soon 
occurring. 
