particles that encounter it impart to it their negative electricity,
and then, since like electric charges repel like, the storm of
particles following will be sheered off from the earth, and will
stream around it in a maze of hyperbolic paths. Those that continue on
into space beyond the earth may be expected to continue picking up
wandering particles of matter until their bulk has become so great
that the solar attraction prevails again over the light pressure
acting upon them, and they turn again sunward. Passing the earth on
their return they will increase the amount of dust-clouds careering
round it; and these will be further increased by the action of the
ultra-violet rays of the sunlight causing particles to shoot radially
away from the earth when the negative charge of the upper atmosphere
has reached a certain amount, which particles, although starting
sunward, will be swept back to the earth with the oncoming streams. As
the final result of all this accumulation of flying and gyrating
particles in the earth's neighborhood, we are told that the latter
must be transformed into the semblance of a gigantic solid-headed
comet provided with streaming tails, the longest of them stretching
away from the direction of the sun, while another shorter one extends
toward the sun. This shorter tail is due to the particles that we have
just spoken of as being driven sunward from the earth by the action of
ultra-violet light. No doubt this whole subject is too technical for
popular statement; but at any rate the general reader can understand
the picturesque side of the theory, for its advocates assure us that
if we were on the moon we would doubtless be able to see the
comet-like tails of the earth, and then we could appreciate the part
that they play in producing the phenomenon of the Zodiacal Light.

That the Light as we see it could be produced by the reflection of
sunlight from swarms of particles careering round the earth in the