OBTAINED AT THE TOTAL SOLAR ECLIPSES OF 1900, 1901 AND 1905. 
443 
Wave¬ 
length. 
Intensity 
in the— 
Wave¬ 
length. 
Intensity 
in the— 
Chromo¬ 
sphere. 
Sun. 
Spark. 
Arc. 
Chromo¬ 
sphere. 
Sun. 
Spark. 
Arc. 
3733 
4 
7 
10 
8 
3816 
6 
15 
9 
8 
3738 
3 
3 
3 
6 
3824 
7 
6 
7 
8 
3745 
10 
12 
7 
8 
3826 
8 
20 
9 
8 
l 6 
7 
6 
3828 
7 
8 
9 
8 
3748 
7 
10 
7 
6 
3834 
8 
10 
8 
8 
3749 
4 
20 
8 
10 
3856 
4 
8 
8 
8 
3758 
4 
15 
8 
8 
3860 
5 
20 
9 
10 
3763 
7 
10 
7 
8 
3873 
4 
7 
8 
8 
3765 
3 
6 
5 
8 
3886 
4 
15 
8 
6 
3767 
6 
8 
7 
8 
3895 
3 
7 
5 
6 
3788 
3 
9 
5 
6 
3899 
3 
8 
6 
6 
3790 
3 
5 
3 
6 
3923 
2 
12 
6 
8 
3795 
3 
8 
8 
6 
3928 
4 
8 
7 
8 
3799 
4 
7 
7 
6 
3930 
4 
8 
6 
8 
The intensities of the lines in the chromosphere on the whole follow the spark 
spectrum most nearly. It may be noticed, too, that the lines which are specially 
strong in the sun (compare, e.g ., 3826 and 3828) are not specially strong in the 
chromosphere, spark, or arc. 
The most striking enhanced lines are not in this part of the spectrum. The 
following list gives some of those which are very faint in the spark with a comparison 
with neighbouring arc lines :— 
Nickel. 
Nickel is v # ery weak in the chromospheric spectrum. About a dozen lines can with 
considerable probability be attributed to it. These are the strongest spark lines of 
3 L 2 
