J. C. Draper—Dark Lines in the Solar Spectrum. 261 
one else to other elements, which are very nearly coincident 
with the oxygen lines, as determined by the photographic 
method, as will be seen in the table at the close of this article. 
hat gas. 
The first column contains the wave lengths of certain lines in 
the chart made from photographs of the solar spectrum. The 
second the wave lengths of the lines of the condensed electric 
spark in oxygen. The third Pliicker’s lines of oxygen, which 
are much more numerous than those of Huggins, which are 
resented in the fourth column, while the fifth column gives 
the lines of Angstrém’s air spectrum, which may be credited 
to oxygen. The term free in the first column is used to indi- 
cate the fact that no element has heretofore been found to 
give a line within two or three tenths of a wave length of that 
ition. It is therefore free to be assigned as an oxygen line. 
the chemical symbols on the other lines show that the element 
indicated has been assigned to that line, and shares it with 
oxygen. The number of lines of greater wave length than 
3961°60, which are free from other elements, and which are 
assignable to oxygen, is good evidence of its presence in the 
solar envelopes. 
Draper. DRAPER. Piicxer. | Hvuaass. | Anesrrom. 
Photographic chart |. Eco of * Lines ot Lines of eae 
with th: wig eae} Sal tn pei a oxygen, oxygen. saa ; 
ete 
3864-50? free. | 3864-75! 
3882°309 + 3882-303 
3907-90? « 8-00! 
3912-253 « 3912-353 
3919-753 « 3919-502 
3945-10! «& 394 
3954603 3954-70 
61-604 « 
3973-403 & 3973-5010 
Sees yh). 3982-70" 
3995-503 “ 8995°505 
: 406950" | 4069-003 4069-00° 4069°50 
aa & : : 4071°65 
4072-103 4071-90" | 4072-003 4073-008 | ped Bn 
4075-50? « 4075°451° 4075°50 
4084-704 4084:805 4085-004 
4088-09! « 4087-804 4086-002 
4093-201 « 4093-104 | 4094-002 
4104-40? « 4104-508 4104-002 4103-00 
4111-002 « 4111-104 
4118-007 Fe, 4118-20 | 4117-002 4117-002 
4121-208 4121-208 
