He reverts again presently to the topic of this sponge caught lunar atmosphere. I am told by astronomers and physicists that all he tells is in absolute accordance with what was already known of the moon’s condition. Had earthly astronomers had the courage and imagination to push home a bold induction, says Mr. Wendigee, they might have foretold almost everything that Cavor has to say of the general structure of the moon. They know now pretty certainly that moon and earth are not so much satellite and primary as smaller and greater sisters, made out of one mass, and consequently made of the same material. And since the density of the moon is only three-fifths that of the earth, there can be nothing for it but that she is hollowed out by a great system of caverns. There was no necessity, said Sir Jabez Flap, F.R.S.