1884.] Most Widened Lines in Sun-spot Spectra. 445 



o 



2. On February 26th, 1880, faint lines not marked in Angstrom's 

 atlas appeared among the most widened lines. 



3. A change took place in the spectra of the sun-spots in May 

 and June, 1881, the old lines faded away and new lines appeared. 



3a. The lines of iron fade away from the spots as the maximum 

 sun-spot period is approached. 



4. In October, 1881, a similar change topk place, only much more 

 abrupt. 



5. During the second hundred observations a much greater number 

 of Fraunhoferic lines have been seen wider than in the first, but with 

 less frequency. 



6. The most widened lines have shifted towards the less refrangible 

 part of the spectrum. 



7. In some spots certain lines have indicated change of refrangi- 

 bility, while other lines in the same region have not done so. 



7a. On several occasions certain lines of iron have been seen in 

 motion, while other lines in the same field of view have been at 

 rest. 



8. There are immense inversions in the lines seen widened in the 

 spots from spot to spot, and from day to day. 



9. There is a great inversion between the iron lines seen among the 

 most widened lines. 



10. There are yet greater variations between the lines brightened 

 in prominences and widened in spots. 



11. On comparing Young's chromospheric lines with the most 

 widened lines, it is found that the number of common lines increases 

 till the end of the third period, and then it falls. 



11a. There is a great difference between the lines seen in promi- 

 nences by Young at the maximum and those seen by Tacchini at the 

 minimum sun-spot periods. 



11b. In the region between F and b there are no iron lines common 

 to the most widened lines and Tacchini's observations of promi- 

 nences. 



12. Even with a six-fold complexity I was unable to classify the 

 most widened iron lines. 



13. The spectrum of iron in the sun is more like that given by the 

 spark than that given by the arc. 



14. Of three iron lines at 4918*0, 4919'8, and 4923'1 the two former 

 have been seen in spots among the most widened lines, while Tacchini 

 and others have seen the latter without the former in prominences. 



15. The prominence line 4923' 1 is sometimes seen under certain 

 conditions brighter than the longest iron line, in the region at 

 49567. 



16. The lines of iron, manganese, zinc, titanium, nickel, and copper 

 most frequently seen in spots are different from those most frequently 



