446 On the Most Widened Lines in Sun-spot Spectra. [Mar. 20, 



seen in prominences, whilst in cobalt, chromium, and calcium they are 

 the same. 



17. The lines of iron, cobalt, chromium, manganese, titanium, and 

 nickel seen in the spectra of spots and prominences are usually 

 coincident with lines in the spectra of other metals with the 

 dispersion employed, whilst the lines of tungsten, copper, and zinc are 

 not. 



18. All the lines of titanium seen among the most widened lines 

 have either been greatly developed in passing from the arc to the 

 spark, or else have been seen only in the spark. 



19. The lines of titanium, zinc, and nickel, seen widened in the 

 fourth period, are not the same as those seen in the first. 



20. Several of the new lines seen among the most widened lines 

 occupy positions near those occupied by titanium lines. 



21. No lines of cobalt, manganese, chromium, copper, or tungsten, 

 were seen in the fourth period. 



22. A strong barium lino has been seen once among the most 

 widened lines ; it is a line greatly intensified in passing from the arc 

 to the spark. 



23. A hundred and one lines have been seen among the most 

 widened lines which have no corresponding lines (so far as is known) 

 in the spectra of the elements. One of these lines has been seen 

 frequently in prominences by Yojng. 



24. So far as the observations have gone, there has been no differ- 

 ence caused by the nearness of the spot to the limb. 



