458 MR WILLIAM SWAN ON THE 
rated from the moon’s edge when first seen, and the separation increased as the 
moon advanced.”* 
My own observations of the prominences are accordant with those which 
have now been stated. A little after the commencement of the total phase, 
I determined their positions, and then left the telescope to make some other 
observations. On returning to the telescope, I found that the prominences on 
the moon’s western limb had increased very sensibly in height; and on watch- 
ing the hook-shaped prominence,—which I did until a few seconds before the end of 
the totality,—it seemed to rise from behind the moon, its base increasing in breadth, 
while the contour of the portions which were already visible, remained quite un- 
altered. Its motion, relatively to the moon, seemed to me quite sensible; but, 
although I may posssibly have been mistaken in this, I feel, no doubt whatever as 
to the striking difference between its height when first seen and that which it 
finally attained. Figs. 7 and 8, Plate XI., which are taken from a sketch made im- 
mediately after the total phase, represent this prominence as it was first and last 
seen. From its accidental resemblance to an object with whose form I happened 
to be familiar,} its shape was very distinctly impressed on my memory; and I feel 
satisfied that the change which took place in its appearance as the eclipse ad- 
vanced, was precisely such as would have happened to a body of permanent form 
belonging to the sun, from which the moon gradually receded and left more and 
more of it exposed. 
Numerous observers of the late eclipse, therefore, bear decided testimony to the 
fact, that the prominences situated on the side towards which the moon was moy- 
ing, were occulted by it, while those on the opposite side were gradually exposed ; 
and, at the same time, all are equally certain that the forms of those objects were 
in no other respect altered. I conceive, then, that unless we suppose they 
were deceived as to one or other of these points, we cannot hesitate to admit that 
the prominences are material objects, and that they exist in the sun. For if they 
were optical phenomena, it is quite inconceivable that the moon’s motion should 
alter their height alone, while it did not at the same time affect their forms.t 
The discussion of the observations of the late eclipse seems, then, to lead to 
the following results :— ; 
1. The red prominences are not caused by the telescopes used in observing the 
eclipse ; for they were seen with the naked eye. 
* Ast. Nachricht., No. 777, p. 157. + P. 342. 
{ The occultation of the prominences on the east side by the advancing moon, serves to explain 
some of the variations in the statements of different observers, as to their number. Mr Lassex1’s 
observations already cited, shew that an observer might be too late on the outlook to see some of the 
prominences on the east side. Mr Dunkin, Mr Jacxson, Mr Hinp, Mr Perrersson, and myself, 
all saw no prominences to the east of the sun’s vertex. At least three of these observers had their 
attention withdrawn from the red prominences by registering the time, and by making naked eye 
observations at the commencement of the total phase; while in Mr Dunxr’s case, the sun was 
covered with a cloud shortly after the commencement of the totality, and the prominences were not 
looked for until after it had passed away. 
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