net. The other, and more important one, is that the
search for planetoids has naturally been carried on in that
comparatively narrow zone within which most of their orbits fall; and
that, consequently, those having the most highly-inclined orbits are the
least likely to have been detected, especially if they are at the same
time among the smallest. Moreover, considering the general relation
between the inclination of planetoid orbits and their eccentricities, it
is probable that among the orbits of these undetected planetoids are
many of the most eccentric. But while recognizing the incompleteness of
the evidence, it seems to me that it goes far to justify the hypothesis
of Olbers, and is quite incongruous with that of Laplace. And as having
the same meanings let me not omit the remarkable fact concerning the
planetoids discovered by D'Arrest, that "if their orbits are figured
under the form of material rings, these rings will be found so
entangled, that it would be possible, by means of one among them taken
at hazard, to lift up all the rest,"--a fact incongruous with Laplace's
hypothesis, which implies an approximate concentricity, but quite
congruous with the hypothesis of an exploded planet.

Next to be considered come phenomena, the bearings of which on the
question before us are scarcely considered--I mean those presented by
meteors and shooting stars. The natures and distributions of these
harmonize with the hypothesis of an exploded planet, and I think with no
other hypothesis. The theory of volcanic origin, joined with the remark
that the Sun emits jets which might propel them with adequate
velocities, seems quite untenable. Such meteoric bodies as have
descended to us, forbid absolutely the supposition of solar origin. Nor
can they rationally be ascribed to planetary volcanoes. Even were their
mineral characters appropriate, which many of them are not (for
volcanoes do not eject iron), no planetary volcanoes could propel them
with anything like the implied velocity--could no more withstand the
tremendous force to be assumed, than could a card-board gun the force
behind a rifle bullet. But that their mineral characters, various as
they are, harmonize with the supposition that they were derived from
the crust of a planet is manifest; and that the bursting of a planet
might give to them, and to shooting stars, the needful velocities, is a
reasonable conclusion. Along with those larger fragments of the crust
const