e discovery that a great planet circulated beyond Uranus.
The new body, which received the name of Neptune, was brought to light
as the result of calculations made at the same time, though quite
independently, by the Cambridge mathematician Adams, and the French
astronomer Le Verrier. The discovery of Neptune differed, however, from
that of Uranus in the following respect. Uranus was found merely in the
course of ordinary telescopic survey of the heavens. The position of
Neptune, on the other hand, was predicted as the result of rigorous
mathematical investigations undertaken with the object of fixing the
position of an unseen and still more distant body, the attraction of
which, in passing by, was disturbing the position of Uranus in its
revolution around the sun. Adams actually completed his investigation
first; but a delay at Cambridge in examining that portion of the sky,
where he announced that the body ought just then to be, allowed France
to snatch the honour of discovery, and the new planet was found by the
observer Galle at Berlin, very near the place in the heavens which Le
Verrier had mathematically predicted for it.

Nearly fifty years later, that is to say, in our own time, another
important planetary discovery was made. One of the recent additions to
the numerous and constantly increasing family of the asteroids, a tiny
body brought to light in 1898, turned out after all not to be
circulating in the customary space between Mars and Jupiter, but
actually in that between our earth and Mars. This body is very small,
not more than about twenty miles across. It has received the name of
Eros (the Greek equivalent for Cupid), in allusion to its insignificant
size as compared with the other leading members of the system.

This completes the list of the planets which, so far, have revealed
themselves to us. Whether others exist time alone will show. Two or
three have been suspected to revolve beyond the path of Neptune; and it
has even been asserted, on more than one occasion, that a planet
circulates nearer to the sun than Mercury. This supposed body, to which
the name of "Vulcan" was provisionally given, is said to have been
"discovered" in 1859 by a French doctor named Lescarbault, of Orgeres
near Orleans; but up to the present there has been no sufficient
evidence of its existence. The reason why such uncertainty should exist
upon this point is easy enough to understand, when we consider the
overpowering glare