Haren me 
W. 7. Sampson—Spectrum of the Corona. 345 
Several observers during the recent eclipse failed to see the dark 
lines, though they looked for them carefully. While I do not 
uestion the results of observers who report the presence of 
ark lines I think all the observations taken together show 
that the continuous spectrum of the corona is not the spectrum 
of the sun. Aside from this, Prof. Arthur W. Wright made 
measurements of the polarization of the light of the corona, 
the first time I think it has been attempted, and has found 
the polarization to be but a small percentage of the whole light 
emitted. Although all reflected light does not reach us as polar- 
wed light, yet I think the small percentage of polarization 
taken with the faintness of the dark lines indicates that the cor- 
ona is to a considerable extent self-luminous. The meteoric 
dust not only reflects the sun's light but it is continually show- 
ering upon the sun and in its passage through its atmosphere 
is rendered incandescent. 
No photographs of the spectrum of the corona can probably 
throw any light upon the matter. 
August 31, 1871, 
