210 KANSAS ACADEMY OF SCIENCE. 
Vy. ASTRONOMY. 
THE CORONA OF THE SUN. 
BY EPHRAIM MILLER, UNIVERSITY OF KANSAS, LAWRENCE. 
A lecture delivered before the Academy at its annual meeting, at McPherson, December 29, 1899. 
Prof. C. A. Young, perhaps the most competent authority upon solar phe- 
nomena, writing about the sun’s corona, says: ‘‘We must evidently wait awhile 
for the solution of the problems presented by the beautiful phenomenon. Pos- 
sibly the time may come when some new contrivance may enable us to see and 
study the corona in ordinary daylight, as we now do the prominences. The 
spectroscope, indeed, will not accomplish the purpose, since the rays and stream- 
ers of the corona give a continuous spectrum; but it would be rash to say that 
no means will ever be found for bringing out the structures around the sun 
which are hidden by the glare of our atmosphere. Unless something like this 
can be done, the progress of our knowledge must be very slow, for the corona is 
visible only about eight days in a century, in the aggregate, and then only over 
narrow stripes on the earth’s surface, and but from one to five minutes at a time 
by any one observer.”’ 
Sir Robert S. Ball, in ‘‘The Story of the Sun,’’ says: ‘‘Such is an outline of 
the facts known to us with regard to the corona; and it must be admitted that 
our information is at present of a somewhat meager description. We can only 
hope that the attempts to photograph the corona without having to wait fora 
total eclipse may ultimately prove successful. 
‘‘Doubtless many of our perplexities would vanish if a series of observations 
taken at brief intervals were certainly available. We might then expect to gain 
information regarding the changes in the corona, which it seems absolutely cer- 
tain are in progress. We might expect, too, that some satisfactory evidence 
might be forthcoming as to the actual character of the material to which the 
coronal light is due.” 
In Langley’s splendid book, ‘‘The New Astronomy,”’ we read: ‘‘ Outside all 
is the strange shape which represents the mysterious corona, seen by the naked 
eye in a total eclipse, but at all other times invisible even to telescope and spec-. 
troscope, and of whose true nature we are nearly ignorant from lack of oppor- 
tunity to study it.’’ On page 40, the same author says: ‘‘The sun went out as 
suddenly as a blown-out gas jet, and I became as suddenly aware that all around 
there had been growing into vision a kind of ghostly radiance, composed of sepa- 
rate pearly beams, looking distinct each from each, as though the black circle 
where the sun once was bristled with pale streamers, stretching far away from 
it in a sort of crown. This was the mysterious corona, only seen during the brief 
moments while the shadow is flying overhead.”’ 
The French astronomer, Flammarion, says, in his ‘‘ Popular Astronomy’’: 
‘‘ What, then, is the corona? It is probably a region in which is found a variable 
quantity of detached particles, partially or wholly vaporized by the intense heat 
to which they are exposed. But how can these particles be supported in these 
burning heights? To this question we are already able to give three replies: 
(1) The matter of the corona may be in a state of permanent projection, being 
