three errors, the effect of one of which
would be to increase the true answer 111 times, of another 28 times,
and of a third to diminish it 10 times; so that the final result is
more than 300 times too great. If this result were correct, Leverrier
would have no need of looking for intermercurial planets to account
for the motion of the perihelion of Mercury; he would find a
sufficient cause in the ellipticity of the sun.

Considered from a scientific point of view, some of the gravest
errors into which the author has fallen are the suppositions, that
the perihelia and nodes of the planetary orbits move uniformly, and
that they can ever become exactly circular. At the end of about
twenty-four thousand years the eccentricity of the earth's orbit will
be smaller than at any other time during the next two hundred
thousand, at least; but it will begin to increase again long before
the orbit becomes circular. Astronomers have long known that the
eccentricity of Mercury's orbit will never be much greater or much
less than it is now; and moreover, instead of diminishing, as stated
by Professor Mitchell, it is increasing, and has been increasing for
the last hundred thousand years.

Finally, the chapter closes with an attempt to state the principle
known to mathematicians as "the law of the conservation of areas,"
which statement is entirely unlike the correct one in nearly every
particular.

It will be observed that we have criticized this work from a
scientific rather than from a popular point of view. As questions of
popular interest, it is perhaps of very little importance whether the
earth's orbit will or will not become circular in the course of
millions of years, or in what the principle of areas consists or does
not consist. But if such facts or principles are to be stated at all,
we have a right to see them stated correctly. However, in the first
nine chapters, which part of the book will be most read, few mistakes
of any importance occur, and the method pursued by Newton in deducing
the law of gravitation is explained in the author's most felicitous
style.

* * * * *

_El Fureidis_. By the Author of "The Lamplighter" and "Mabel
Vaughan." Boston: Ticknor & Fields. 16mo.

That large army of readers whose mere number gave celebrity at once
to the authoress of "The Lamplighter" will at first be disappointed
with what they may call the location of this new romance by Miss
Cummins. Th