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 rarefied 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