Chester.
_Astronomical Query_ (Vol. vii., p.84.).--Your fair correspondent LEONORA
makes a mistake in reference to the position, in regard to the zodiac, of
the newly-discovered planets. It is indeed not at all surprising that these
bodies were not discovered before, for this reason--they _do not move
within the circle of the zodiac_: they lie far beyond it, so much so, that
to include them the zodiac must be expanded to at least five times its
present breadth. Hence they lie out of the path of ordinary observation,
and their discovery is usually the result of keen telescopic examination of
distant parts of the heavens. LEONORA is of course aware, that, with the
exception of Neptune (the discovery of which is a peculiar case), all the
recently discovered planets belong to the cluster of asteroids which move
between Mars and Jupiter. These are all invisible to the eye with the
exception of Vesta, and she is not to be distinguished by any but an
experienced star-gazer, and under most favourable circumstances; their
minuteness, their _extra_-zodiacal position, and the outrageous orbits
which they describe, all conspire to keep them out of human ken until they
are detected by the telescope, and ascertained to be planets either by
their optical appearances, or by a course of watching and comparison of
their positions with catalogues of the fixed stars.