’ 
d+ OC. S. Hastings—Constitution of the Sun. 
length, which was kindly placed at my disposal by the gentle- 
men in Hartford, to whom it belongs.* e New Have 
spectroscope too, of 12 effective prisms, was replaced by one of 
which the dispersing member was a Rutherfurd grating on 
Sie metal, either of 8648 or 17296 lines to the inch at 
will. These gratings were of the i se size, having a ruled 
surface of about 12 inches square. 
The immediate results I give in order of refrangibility of 
the lines observed, as no observed variations in them can be 
attributed to anything other than the temporary modifications 
of transparency in our atmosphere. ‘he numbers are the 
places on Angstrém’s maps as nearly as could be ascertained 
without micrometer. 
Line (C) 6561°8 is cleaner and wider at limb, i. e. ree hhaze on 
either side of the line as ordinarily seen is much re 
6431 is slightly stronger at center than at limb. 
6371 is visible at center but not at limb. 
(D,) 5894°8 slightly less hazy at limb. “i 
(D,) 5889-0 decidedly cleaner at lim hy 
A fine line very close to its more refrangible side is either want- 
b. 
- ing or much fainter in spectrum of lim 
5577°5 is much stronger at lim 
5440 + (not on Angstrém’s chart) i is a little stronger at limb. 
The Mg lines 5183-0, 5172°0, 5166°5 (5, 6,5,) are cleaner at limb. 
The oe b, belonging to a different element does not show such a 
peculia 
ree ts faint line not in A.) is stronger at limb. 
9 +, a faint line slightly stronger at lim 
(F) 4860°6 is much cleaner, more free from haze at limb. 
4702°3 seems ree at limb. 
4340°0 cleaner at li 
4226°4 shows less hate at limb. 
41012 is a very hazy line, so Le Sangha by Angstrém ; but at 
limb it is practically free from haze—a striking difference. 
4045 is slightly less hazy at limb. 
Other ts Raa have been recorded, but only these have 
been observed more than once eac 
Any theory of the sun, worthy of attention, must not only 
explain the above described phenomena, but also others better 
known, and as yet not accounted for satisfactorily. Of these 
the most noteworthy is the spectroscopic appearance of a spot 
and its penumbra. As is well known, such a spectrum eX- 
hibits a very strong general absorption, with a very slightly 
modified elective absorption. A few faint lines appear in the 
spot spectrum which are not otherwise seen; and a few faint 
* My acknowledgments for this courtesy are gratefully accorded to Mr. ae 
comb its former owner, and to Mr. Howard and Mr. Chapin its present owners 
