494 
MR. J. NORMAN LOCKYER ON SPECTRUM-ANALYSIS. 
Explanation op the Plates. 
PLATE XXXVIII. 
Illustrating use of slit plate. 
Comparison of the spectra of Calcium and Barium with the solar spectrum. 
Upper spectrum Barium, H to beyond G. 
Middle „ Solar „ „ „ 
Lower „ Calcium „ „ „ 
Note. — The Calcium contains Aluminium, Strontium, and Iron as impurities. The 
barium contains the same impurities in addition to calcium. 
PLATE XXXIX. 
Illustrating use of slit plate. 
Confronting of spectra of Manganese, Nickel, Lenarto meteorite, and Iron containing 
calcium and other impurities. 
{ Manganese . . H to beyond G. 
Nickel . . . „ ,, ,, 
Lenarto meteorite ,, „ „ 
Lower „ Impure iron . „ „ „ 
Note. — The Manganese spectrum includes the longest lines of Calcium, Aluminium, 
and Iron. Nickel shows the same impurities in addition to manganese, while the 
longest nickel lines are to be traced in the spectrum of the Lenarto meteorite. 
PLATE XL. 
Illustrating use of horizontal arc. 
Long and short lines near F of impure iron. The lower part gives the spectrum of 
the core of the arc ; the upper part the spectrum of the extreme limits of the vapour. 
