276 H. Draper— Oxygen in the Sun. 
brightness enough for a larger apparatus. Then the difficulty 
of having iron terminals so as to show a good coincidence is a 
serious one. So when I made the spark-compressor I arranged 
a contrivance at the back which would enable me to let in oxy- 
gen and the other gases between the terminals, and after various 
experiments with oxygen I find that it seems to suffer less 
change with altered conditions than a great many of the other 
elements I have experimented on. I have fairly shown that the 
bright lines coincide with bright spaces in the solar spectrum. 
The minor differences may be fairly attributed to such changes 
of condition as Mr. Rand Capron has referred to. With regard 
to Dr. Gladstone’s remark, which was that probably we should 
not find in the chromosphere the lines of the oxygen spectrum. 
That is precisely what I hope will be the case, although I am 
going to look as hard as I can for them. I should like to see 
them if they are there, but I shall be better satisfied if they are 
not. 
A cordial vote of thanks was then passed to Dr. Draper. 
[The photographs of the oxygen spectrum and juxtaposed | 
solar spectrum, were also presented to the French Academy of | 
Sciences in Paris, at the meeting of June 23, 1879, by M. A. 
Cornu. M. Faye made the following remarks, which we trans- 
late from the Comptes Rendus.—Eps. ] 
OM raper has, however, succeeded in discovering the 
oxygen, not in the chromosphere, but in the photosphere, where 
it discloses itself by bright lines. It is obvious that if this gas 
