Astronomy. 313 
venient method of solving the questions relating to the corona 
itself, With this instrument, then, I prepared to observe the 
eclipse, proposing to myself the following problems :— 
L. To ascertain whether, just before the beginning, and at the 
end of totality, the solar spectral lines are reversed—a phenomenon 
observed by Prof. Young in the eclipse of 1870. 
2, Amidst the several chromatic images of the prominences, to 
observe especially whether the image given by the ye low line 
D, coincides with that of the lines of hydrogen gas. 
3, To define the form and dimensions of the chromatic images 
of the corona. wc? 
0 verify the phenomenon of the reversal of the spectral lines at 
the extreme edge of the sun, I had arranged the plane of disper- 
came continuous, without however exhibiting, just before 
totality, the reversal of the lines, although I was watching most 
intently for this phenomenon. I would not, however, be under- 
stood as denying altogether the reversal of the lines, for it is not 
impossible that a thin film of mist, or the bright atmospheric light 
at that time diffused over the spectrum of the solar limb, may 
have concealed the bright lines. 
the very instant of totality, the field of the telescope ex- 
acle. The chromosphere at the 
d 
7 
of light and the most surprising contrast of the brightest colors, 
it 
with the tints of the chromatic images of the corona. My atten: 
tion was mainly directed to the comparison of the forms of the 
nore strongly marked, one in the red corresp nding with the 
line C, another in the "green, probably coinciding with the line 
