"Well, if I had been Pym I should have blown those mountains into the Antarctic Ocean," said Castleton. "I understand from the words that I caught this evening as I entered here that your heroine is safe; but if I had been Pym, I should have taken no risks. I should have sent your madman word to return the girl, or take the consequences--the consequences being that I should have blown him and the entire mountain into the mighty deep. 'Sir,' I should have said, 'return the lady, or I will annihilate you.' And so I should have done, if a hair of her head had been harmed.--By the bye, gentlemen, I believe you never heard of my invention for stopping war, did you?" We intimated that we had thus far been deprived of that pleasure. I saw that one of his peculiar outbursts was at hand--one of those apparently serious, though, I thought, intentionally humorous sallies, so puzzling coming from a man of Castleton's intellectual attainments, and the mental _primum mobile_ of which I had already been much interested in trying to determine. "Well, gentlemen," he continued, "it was about fourteen years ago, during the dark days of The War"--he referred to the great rebellion in the United States, which began in 1861, and which it required the existing government about four years to suppress. "It was during the period when our great President was most worried. I had thought the matter over--as I always do think over vast questions, from the standpoint of true greatness. 'Why not,' I mentally soliloquized, 'why not end this matter at a blow? 'As I drove about through our retired roads and lanes, I gave the subject my very best attention. I thought to myself how the present system of the universe depends upon what we term the luminiferous ether; of the perfect elasticity and inexpansibility of that ether; of what its nature must be. I concluded that no ultimate particle of it--as with matter no atom--is ever added to or removed from the universe. Now, if we could succeed in removing from this inexpansible, universal ocean of ether even the most ultimate portion, there would be a literal vacuum with nothing to fill it, and the equilibrium of the universe would be destroyed. Now, gentlemen, is or is not this supposition logical?" We admitted our inability to deny its truth. "'Well, then,' I reasoned, looking at the subject on the reverse side, 'could an additional portion of ether be created, there would be in space no place to receive it; the universe in its present state--a state in which what we term matter or substance exists--would just simply cease to exist--instantly, and within the compass of every star and planet.'