in respect of their number or relative intensity.
From this entire absence of any special absorption lines, it must be
concluded that there is no atmosphere in the moon, a conclusion
previously arrived at from the circumstance that during an
occultation no refraction is perceived on the moon's limb when a
star disappears behind the disk." [437] Mr. Nasmyth follows in the
same strain. Holding that the moon lacks air, moisture, and
temperature, he says, "Taking all these adverse conditions into
consideration, we are in every respect justified in concluding that
there is no possibility of animal or vegetable life existing on the
moon, and that our satellite must therefore be regarded as a barren
world." [438] A French astronomer holds a like opinion, saying:
"There is nothing to show that the moon possesses an atmosphere;
and if there was one, it would be perceptible during the occultations
of the stars and the eclipses of the sun. It seems impossible that, in
the complete absence of air, the moon can be peopled by beings
organized like ourselves, nor is there any sign of vegetation or of
any alteration in the state of its surface which can be attributed to a
change of seasons." [439] On the same side Mr. Crampton writes
most decisively, "With what we _do_ know, however, of our
satellite, I think the idea of her being inhabited may be dismissed
_summarily_; _i.e._ her inhabitation by intelligent beings, or an
animal creation such as exist here." [440] And, finally, in one of
Maunder's excellent _Treasuries_, we read of the moon, "She has no
atmosphere, or at least none of sufficient density to refract the rays
of light as they pass through it, and hence there is no water on her
surface; consequently she can have no animals like those on our
planet, no vegetation, nor any change of seasons." [441] These
opinions, recorded by so many judges of approved ability and
learning, have great weight; and some may regard their premisses
and conclusions as irresistibly cogent and convincing. The case
against inhabitation is certainly strong. But justice is impartial.
_Audi alteram partem_.

Judges of equal erudition will now speak as respondents. We go
back to the seventeenth century, and begin with a work whose
reasoning is really remarkable, seeing that it is nearly two hundred
and fifty years since it was first published. We refer to the
_Discovery of a New World_ by John Wilkins, Bishop of Chester;
in which the reverend philosop