and movement beneath us. But when West, whose watch it now was, attempted to alter the course of the ship, he found that it did not respond. Instead it continued to move slowly in a great circle around the inside rim of the crater. At the moment of this discovery we were not much more than five hundred feet above the summit of the volcano, and we were constantly, though slowly, dropping. West looked up at us, smiled, and shook his head.
"It is no use, sir," he said, addressing me. "It is about all over, sir, and there won't even be any shouting. We seem to be caught in what one might call a lunar whirlpool, for you will have noticed, sir, that our circles are constantly growing smaller."
"Our speed does not seem to be increasing," I remarked, "as would follow were we approaching the vortex of a true whirlpool."
"I think I can explain it, sir," said Norton. "It is merely due to the action of the Lunar Eighth Ray which still remains in the forward buoyancy tank. Its natural tendency is to push itself away from the Moon, which, as far as we are concerned, is represented by the rim of this enormous crater. As each portion of the surface repels us in its turn we are pushed gently along in a lessening circle, because, as we drop nearer the summit of the peak the greater the reaction of the Eighth Lunar Ray. If I am not mistaken in my theory our circle will cease to narrow after we have dropped beneath the rim of the crater."
"I guess you are right, Norton," I said. "At least it is a far more tenable theory than that we are being sucked into the vortex of an enormous whirlpool. There is scarcely enough atmosphere for that, it seems to me."
As we dropped slowly below the rim of the crater the tenability of Norton's theory became more and more ap-
