IN CONNEXION WITH THE SPECTRUM OF THE SUN. 
813 
Description of the Photographs. 
PLATE LXXXIV. 
Spectrum 1. Long and short lines of calcium. 
Spectrum 2. Long and short lines of strontium. 
Spectrum 3. Long and short lines of barium. 
Note . — In these photographs the impurity lines which have been eliminated from the 
map by the process described in the paper are present. 
The photographs illustrate the use of the horizontal arc. 
PLATE LXXXV. 
Spectrum 1. 
aluminium. 
Comparison of the spectra of the Lenarto meteorite, calcium, and 
1, spectrum of the meteorite. 
2, ,, calcium. 
3, ,, aluminium. 
Spectrum 2. Comparison of the spectra of nearly pure iron and strontium. 
4, spectrum of iron. 
5, „ strontium. 
Spectrum 3. Comparison of the spectra of Matthiessen’s iron and calcium. 
6, spectrum of calcium. 
7, „ iron when cast into ingot. 
8, „ „ before casting. 
