306 W. Crookes—Spectrum of Helium. 
Wave-length. Intensity. 
4121°3 7 Present in all the gases except “cléveite, R.” 
4044°3 9 Present in “uraninite, R,”’ and “ cléveite, R.” 
Absent in the others. 
[ These lines form a very close pair, seen in all 
4026°1 10 4 the samples of gas, except ‘‘ bréggerite, R.” 
402415 6 } Lockyer find a line in bréggerite gas at 
{  4026°5. 
40129 Seen in all the samples of gas. 
7 
4009°2 7 Seen in ‘‘ helium puriss.” 
3964°8 10 The center line of a dense triplet. Only seen in 
“cléveite, KR,” im “helium ‘purigs;4aeo 
‘‘broggerite, L.” Hale gives a chromospheric 
line at 3964. 
3962°3 + Seen in all the samples of gas. 
3948°2 10 Very strong in ‘“uraninite, R,” very faint in 
“cléverite, R,” and not seen in the others. 
Lockyer finds a line in gas from bréggerite at 
3947. There is an eclipse line at the same 
wave-length. 
3925°8 2 Seen in “helium puriss.” 
3917°0 2 Seen in ‘‘ helium puriss.” 
3913-2 + Only seen in “uraninite, R,’ and “helium 
puriss.” Hale gives a chromospheric line at 
3913°5. 
( A very strong triplet, seen in all the samples of 
3890°5 9 | gas. Lockyer finds a line having a wave-length 
38885 10 ~{ 3889 in gas from bréggerite. Hale gives a 
3885'9 9 | chromospheric line at 3888°73. There is a 
| strong hydrogen line at 3889°15. 
3874°6 6 Only seen in “ uraninite, R.” 
3867°7 8 Seen in “helium puriss.” 
SOTO 40010 Seen in all the samples of gas. Deslandres gives 
a chromospheric line at 3819°8. 
3800°6 4 Seen in “helium puriss.” 
3732°5 5 Seen in “helium puriss.” Hale gives a chromo- 
spheric line at 3733°3. 
3705°4 6 Seen in all the samples of gas. Deslandres gives 
a chromospheric line at 3705°9. 
3642°0 8 Only seen in “uraninite,; R.” 
3633°3 8 Seen in “ helium puriss.”’ 
3627°8 5 Only seen in “ uraninite, R.” 
3613°7 9 Seen in “helium puriss.” 
3587°0 5 Seen in“ helium puriss.” 
3447°8 8 Seen in “helium puriss.”’ 
3353°8 5 Seen in “helium puriss.” 
3247°5 2 Seen in “helium puriss.” | 
3187-3 ae The center line of a close triplet. Very faint in 
“cléveite, R,” and ‘“‘uraninite, R,” and strong 
in “helium puriss.” and in ‘ broggerite, L.” 
It is not seen in “ broggerite, R.” 
