Preliminary Note on the S]jectricm of the Corona. 191 



Table of Coronal Eings. 

 Group I. Typical ring, A 5303*7. 



Wave-lengtii. 



Brightness. 

 Max. = 10. 



w ave*lengtli. 



Brightness. 

 Max. = 10. 



3952 -5 



2 



4536 



1 



4007 



1 



4588 -5 



1 



4022 



1 



4657 



1 



4056 



2 



4685-5 



2 



4068 



1 



4714 



1 



4085 



1 



4727 



1 



4121 



1 



4737 



1 



4168 



1 



4768 



1 



4220 



2 



4808 



1 



4231 -3 



5 



4922 



2 



4248 -5 



2 



5125 



1 



4262 



1 



5137 



1 



4400 



1 



5303 -7 



10 



4430 



1 







4518 



1 







Group II. Typical ring, X 3987*0. Group III. Typical ring, X 4359*5 



Wave-length. 



Brightness. 

 Max. = 10. 



3800 



3 



3987-0 



5 



4275 



1 



4568 *5 



3 



Wave-length. 



Brightness. 

 Max. = 10. 



4030 



1 



4192 



1 



4204 



1 



4302 



1 



4323 



2 



4359 -5 



3 



4485 



1 



4648 



1 



4662 



1 



4788 



1 



4890 



1 



5001 



1 



5255 



1 



I have already suggested that the different forms of the coronal 

 rings indicate that they are not all due to the same substance, and 

 the foregoing tables suggest that at least three substances are in 

 question. The attempts which have so far been made to trace the 

 origins of the rings, however, have led to no very definite results, and 

 the coincidences with lines in the spectra of stars and nebulae which 

 were formerly suspected have not yet been completely established. 



Special interest is attached to the question of the presence or 

 absence of carbon flutings. There is a possible trace of the fluting^ 



