When we had heaped up on the cliff a good many hundredweights of the rock, we waited for the flow of the tide, and then, choosing a place where the cliff ran down very steep and straight to the mouth of the cave, we flung the stuff into the water between the mouth and the rocks where we first encountered the shoal of monsters. We watched eagerly to see what happened, and saw a vast number of bubbles come to the surface, and a certain quantity of smoke that floated away on the breeze, but not near such a smother as we had experience of, which made us hope that there was all the more poison in the water. There was a slight current at the foot of the cliffs, setting past the cluster of rocks towards the channel between Red Rock and the island. We walked along for a little space, in the same direction as this current, to see if there was any sign on the surface of the water of our experiment having had any effect. For some little while we saw nothing, and had begun to believe that the monsters were proof against what we had fondly hoped was poison, when we observed some tentacles appearing above the water by the rocks, and also at the base of the cliffs, and by and by the palpitating bodies of the monsters themselves, crawling up as if the water did not very well agree with them. We pelted these creatures very hard with stones and lumps of the strange rock, and though we missed pretty often, yet we hit them pretty often too, and had lively satisfaction when we saw them loose their hold and tumble back into the water as soon as the rock began to fizz. But we could not see that any of them were killed, and had to conclude that the water about the rocks was too deep, and the current moved too fast, for our poisonous substance to work its full effect, and so we went back disappointed, with the problem of making a safe way through the tunnel to the sea as far from solution as ever it was. CHAPTER THE SEVENTEENTH OF THE END OF THE SEA MONSTERS; AND OF THE EVENTS THAT LED US TO RECEIVE THE CREW AS OUR GUESTS