OBTAINED AT THE TOTAL SOLAR ECLIPSES OF 1900, 1901 AND 1905. 
451 
Spectrum of the Corona. 
The following are the wave-lengths determined at the three eclipses of 1900, 190T, 
and 1905:— 
1900. 
1901. 
1905. 
Mean. 
Intensity. 
_ 
5535-8 
5535-8 
2 
— 
5304 
5303-1 
5303-1 
20 
— 
— 
5117-7 
5117-7 
9 
5073 
— 
— 
5073 
l 
4779 
— 
— 
4779 
l 
4725 1 
— 
— 
4725 
_ 
4722 1 
— 
— 
4722 
_ 
4586•3 
— 
— 
4586 
4 
4566-5 
4565 
— 
4566 
6 
4400 
— 
— 
4400 
1 
4358-8 
— 
— 
4359 
4 
4311-3 
_ 
— 
4311 
2 
4230•6 
4230-9 
4231-1 
4231-0 
5 
4130 
— 
— 
4130 
_ 
— 
— 
4087-4 
4087 
_ 
3987-2 
3987 
3987-1 
3987-1 
3 
— 
3891-2 
— 
3891 
_ 
3800-8 
3801-1 
3800-8 
3800-9 
3 
3642-9 
— 
3642-0 
3642-5 
2 
— 
3505 1 
— 
3505 ? 
_ 
3461-3 
— 
— 
3461 
i 
— 
3454 
— 
3454 
9 
— 
3387-9 
— 
3387•9 
12 
3361 1 
— 
3361 1 
— 
The photographs taken in 1905 are in excellent definition in the green and at the 
line 4231. The part from 4500 to 4685 is, unfortunately, not given, as the plates 
were carried back from Sfax separated by thin pieces of card and fogged where these 
were in contact. The lines in the extreme ultra-violet were only obtained in 
Sumatra. The wave-lengths were determined by reference to chromospheric lines by 
means of Hartmann’s formula. 
Experience gained in these three eclipses shows that a slit spectroscope is most 
advantageously used when tangential as nearly as possible to the sun at the point of 
second contact. This applies both to the chromospheric and the corona spectrum. 
q 9 
O !VI jLj 
