We ceased to gaze. We turned to each other, the same thought, the same
question in our eyes. For these plants to grow, there must be some air,
however attenuated, air that we also should be able to breathe.
“The manhole?” I said.
“Yes!” said Cavor, “if it is air we see!”
“In a little while,” I said, “these plants will be as high as we are.
Suppose--suppose after all--Is it certain? How do you know that stuff
is air? It may be nitrogen--it may be carbonic acid even!”
“That is easy,” he said, and set about proving it. He produced a big
piece of crumpled paper from the bale, lit it, and thrust it hastily
through the manhole valve. I bent forward and peered down through the
thick glass for its appearance outside, that little flame on whose
evidence depended so much!
I saw the paper drop out and lie lightly upon the snow. The pink flame
of its burning vanished. For an instant it seemed to be extinguished.
And then I saw a little blue tongue upon the edge of it that trembled,
and crept, and spread!
Quietly the whole sheet, save where it lay in immediate contact with
the snow, charred and shrivelled and sent up a quivering thread of
smoke. There was no doubt left to me; the atmosphere of the moon was
either pure oxygen or air, and capable therefore--unless its tenuity
was excessive--of supporting our alien life. We might emerge--and live!
I sat down with my legs on either side of the manhole and prepared to
unscrew it, but Cavor stopped me. “There is first a little precaution,”
he said. He pointed out that although it was certainly an oxygenated
atmosphere outside, it might still be so rarified as to cause us grave
injury. He reminded me of mountain sickness, and of the bleeding
that often afflicts aeronauts who have ascended too swiftly, and he
spent some time in the preparation of a sickly-tasting drink which he
insisted on my sharing. It made me feel a little numb, but otherwise
had no effect on me. Then he permitted me to begin unscrewing.
Presently the glass stopper of the manhole was so far undone that the
denser air within our sphere began to escape along the thread of the
screw, singing as a kettle sings before it boils. Thereupon he made me
desist. It speedily became evident that the pressure outside was very
much less than it was within. How much less it was we had no means of
telling.
I sat grasping the stopper with both hands, ready to close it again if,
in spite of our intense hope, the lunar atmosphere should after all
prove too rarified for us, and Cavor sat with a cylinder of compressed
oxygen at hand to restore our pressure. We looked at one another in
silence, and then at the fantastic vegetation that swayed and grew
visibly and noiselessly without. And ever that shrill piping continued.
My blood-vessels began to throb in my ears, and the sound of Cavor’s
movements diminished. I noted how still everything had become, because
of the thinning of the air.
As our air sizzled out from the screw the moisture of it condensed in
little puffs.
Presently I experienced a peculiar shortness of breath, that lasted
indeed during the whole of the time of our exposure to the moon’s
exterior atmosphere, and a rather unpleasant sensation about the ears
and finger-nails and the back of the throat grew upon my attention, and
presently passed off again.
But then came vertigo and nausea that abruptly changed the quality of
my courage. I gave the lid of the manhole half a turn and made a hasty
explanation to Cavor; but now he was the more sanguine. He answered me
in a voice that seemed extraordinarily small and remote, because of the
thinness of the air that carried the sound. He recommended a nip of
brandy, and set me the example, and presently I felt better. I turned
the manhole stopper back again. The throbbing in my ears grew louder,
and then I remarked that the piping note of the outrush had ceased. For
a time I could not be sure that it had ceased.
“Well?” said Cavor in the ghost of a voice.
“Well?” said I.
“Shall we go on?”