934 REPORT—1885. 
to have a higher potential than it possessed as forming part of the sun, and in 
this way too might come about some of the varying conditions upon which the 
observed changes in the corona may depend. 
The photosphere is the seat of ceaseless convulsions and outbursts of fiery 
matter. Storms of heated gas and incandescent hail rush upwards, or in cyclones, 
as many miles ina second as our hurricanes move in an hour. Is it then going 
beyond what might well be to suppose that some portions of the photospheric 
matter, having an electric potential of the same name as that of the solar surface, 
and ejected, as is often the case, with velocities not far removed from that which 
would be necessary to set them free from the sun’s attraction, should come under 
the action of an electric repulsion, and so be carried upwards from the sun P 
If we accept this view of things, many of the coronal phenomena can be satis- 
factorily explained. 
1. The yery long coronal rays, which rest upon sufficient testimony, no longer 
appear improbable. 
2. The peculiar curved rays within the corona may well arise from the smaller 
rotational velocity of the photospheric matter, which would make it lag behind as. 
it rose from the sun, and from probably varying directions of the force of eruption 
combined with the repulsive force acting radially. 
8. We should expect to find the largest coronal extensions over the spot- 
latitudes where solar activity appears to be greatest. 
4. We have an explanation of the rapidly increasing tenuity of the coronal 
matter from the sun, as the repulsion existing between the similarly electrified 
particles would cause them to separate from each other. 
5. The gas carried up with the solid or liquid particles would constantly vary 
in amount, and also in the height to which it was carried asa gas. This state of 
things is in accordance with the great differences observed in the’ spectra of different 
parts of the corona, and in the spectra of the same parts at different times. 
6. If the corona consists of electrified particles, it may well be that the planets. 
especially Venus and Mercury, may have an influence in determining the mode of 
outflow of this electrified matter in the directions in which they happen to be. 
M. Trouvelot, in his report of the eclipse of 1878,' pointed out that the two great 
coronal extensions which were remarkable at that eclipse were directed respec- 
tively to the planets Mercury and Venus. General Tennant informs me that some 
recent calculations show that at the eclipse of 1871 the positions of Mercury and of 
Venus coincided with the two positions of greatest coronal extension. He considers 
further that at the eclipse of 1882 the combined effect of these planets is distinctly 
shown ‘in the protruding angle at the upper left side of the engraved corona in the 
“ Phil. Trans.” 1882.’ ; 
7. It seems obvious, that, if the corona is due to a supply of matter and to 
forces coming from the sun, the coronal structure and the degree of extension 
which are produced by them at any part of the sun, would continue to be produced 
by these agencies at that part of the sun; and in that sense the corona would 
rotate. In the case of the more distant and diffused parts the rotation could 
scarcely be of one and the same material object, any more than in the sweep of a. 
comet’s tail at perihelion. The action of any external force, as that of a planet, 
would continue to be in the direction of this object, and independent of the solar 
rotation. 
8. Eye-observations, and photographs taken with different exposures appear to 
show that the corona has not an outer boundary, but that it is lost in increasing 
faintness and diffusion. Many of the coronal particles under the influence of the 
electric repulsion would leave the sun, and at the same time separate more widely 
from each other, becoming too diffused to be longer visible. 
9. This ceaseless outflow of extremely minute particles from the sun, very 
widely separated from each other, may possibly throw some light on another 
phenomenon which has not yet been satisfactorily accounted for, namely, the 
zodiacal light. 
10. The view of the sun as an electrically charged body may throw some light. 
) Reporé of Total Eclipse, 1878; Washington, p. 93. 
