consent that the canal-system of Mars develops from pole to
equator. From the respective times at which the minima take place, it
appears that the canal quickening occupies fifty-two days, as evidenced
by the successive vegetal darkenings, to descend from latitude 72 deg. north
to latitude 0 deg., a journey of 2650 miles. This gives for the water a
speed of fifty-one miles a day, or 2.1 miles an hour. The rate of
progression is remarkably uniform, and this abets the deduction as to
assisted transference. But the fact is more unnatural yet. The growth
pays no regard to the equator, but proceeds across it as if it did not
exist into the planet's other hemisphere. Here is something still more
telling than travel to this point. For even if we suppose, for the sake
of argument, that natural forces took the water down to the equator,
their action must there be certainly reversed, and the equator prove a
dead-line, to pass which were impossible" (pp. 374-5).

I think my readers will agree with me that this whole argument is one of
the most curious ever put forth seriously by an eminent man of science.
Because the polar compression of Mars is about what calculation shows it
ought to be in accordance with its rate of rotation, its surface is in a
state of 'fluid equilibrium,' and must therefore be absolutely level
throughout. But the polar compression of the earth equally agrees with
calculation; therefore its surface is also in 'fluid equilibrium';
therefore it also ought to be as perfectly level on land as it is on the
ocean surface! But as we know this is very far from being the case, why
must it be so in Mars? Are we to suppose Mars to have been formed in
some totally different way from other planets, and that there neither is
nor ever has been any reaction between its interior and exterior forces?
Again, the assumption of perfect flatness is directly opposed to all
observation and all analogy with what we see on the earth and moon. It
gives no account whatever of the numerous and large dark patches, once
termed seas, but now found to be not so, and to be full of detailed
markings and varied depths of shadow. To suppose that these are all the
same dead-level as the light-coloured portions are assumed to be,
implies that the darkness is one of material and colour only, not of
diversified contour, which again is contrary to experience, since
difference of material with us always leads to differences in rate of
degradation, and