xxin.] GENERAL STATEMENTS. ^313 



ejections from the most highly heated part of the sun below the 

 photosphere, or are caused by the dissociation of the descending 

 material when it has reached the point of highest temperature. 



This being premised we pass on to the results obtained by 

 the spot observations, including with them the results of the 

 comparison with the prominence spectra. I will begin with the 

 results obtained by the complete discussion of the first hundred 

 observations taken between November, 1879, and September, 

 1880. Each line observed in each spot was carefully mapped on 

 a large scale on sheets on the top of which were shown the Fraun- 

 hofer lines with their true intensities in the region explored. 



General Statements regarding Spots. 



1. The spot-spectra are very unlike the ordinary spectrum 

 of the sun, some Fraunhofer lines are omitted, new lines appear 

 and the intensities of the old lines are changed. 



2. The next point was that in the case of each chemical 

 element, even those with many lines among the Fraunhofer lines, 

 only a very few lines, comparatively speaking, were seen to be 

 most widened. It was as if on a piano only a few notes were 

 played over and over again, always producing a different tune. 



8. An immense variation, from spot to spot, was observed 

 between the most widened lines seen in the first hundred 

 observations. Change of quality or density will not account 

 for this variation. To investigate this point I had the in- 

 dividual observations of lines seen in the spectrum of iron 

 plotted out on strips of paper, and I then tried to arrange 

 them in order, but I could not succeed, for even when the 

 observations were divided into six groups about half of them 

 were left outstanding. 



4. If we consider the lines' of any one substance, there is as 

 much inversion between these lines as between the lines of any 

 two metals. By the term inversion I mean of any three lines, 



