The next day we continued our explorations by land, and so for a week after that. I thought it best not to relinquish all authority, so I organised regular expeditions, and ordered their direction. The men did not object. It was all good enough fun to them.

The net results were that we found a nesting place of sea birds--too late in the season for eggs; a hot spring near enough camp to be useful; and that was about all. The sheep were the only animals on the island, although there were several sorts of birds. In general, the country was as I have described it--either volcanic or overlaid with fertile earth. In any case it was canon and hill. We soon grew tired of climbing and turned our attention to the sea.

With the surf boat we skirted the coast. It was impregnable except in three places: our own beach, that near the seal rookery, and on the south side of the island. We landed at each one of these places. But returning close to the coast we happened upon a cave mouth more or less guarded by an outlying rock.

The day was calm, so we ventured in. At first I thought it merely a gorge in the rock, but even while peering for the end wall we slipped under the archway and found ourselves in a vast room.

Our eyes were dazzled so we could make out little at first. But through the still, clear water the light filtered freely from below, showing the bottom as through a sea glass. We saw the fish near the entrance, and coral and sea growths of marvellous vividness. They waved slowly as in a draught of air. The medium in which they floated was absolutely invisible, for, of course, there were no reflections from its surface. We seemed to be suspended in mid-air, and only when the dipping oars made rings could we realise that anything sustained us.

Suddenly the place let loose in pandemonium. The most fiendish cries, groans, shrieks, broke out, confusing themselves so thoroughly with their own echoes that the volume of sound was continuous. Heavy splashes shook the water. The boat rocked. The invisible surface was broken into facets.

We shrank, terrified. From all about us glowed hundreds of eyes like coals of fire--on a level with us, above us, almost over our heads. Two by two the coals were extinguished.

Below us the bottom was clouded with black figures, darting rapidly like a school of minnows beneath a boat. They darkened the coral and the sands and the glistening sea growths just as a cloud temporarily darkens the landscape--only the occultations and brightenings succeeded each other much more swiftly.

We stared stupefied, our thinking power blurred by the incessent whirl of motion and noise.

Suddenly Thrackles laughed aloud.

"Seals!" he shouted through his trumpeted hands.

Our eyes were expanding to the twilight. We could make out the arch of the room, its shelves, and hollows, and niches. Lying on them we could discern the seals, hundreds and hundreds of them, all staring at us, all barking and bellowing. As we approached, they scrambled from their elevations, and, diving to the bottom, scurried to the entrance of the cave.

We lay on our oars for ten minutes. Then silence fell. There persisted a tiny _drip, drip, drip_ from some point in the darkness. It merely accentuated the hush. Suddenly from far in the interior of the hill there came a long, hollow _boo-o-o-m_! It reverberated, roaring. The surge that had lifted our boat some minutes before thus reached its journey's end.

The chamber was very lofty. As we rowed cautiously in, it lost nothing of its height, but something in width. It was marvellously coloured, like all the volcanic rocks of this island. In addition some chemical drip had thrown across its vividness long gauzy streamers of white. We rowed in as far as the faintest daylight lasted us. The occasional reverberating _boom_ of the surges seemed as distant as ever.

This was beyond the seal rookery on the beach. Below it we entered an open cleft of some size to another squarer cave. It was now high tide; the water extended a scant ten fathoms to end on an interior shale beach. The cave was a perfectly straight passage following the line of the cleft. How far in it reached we could not determine, for it, too, was full of seals, and after we had driven them back a hundred feet or so their fiery eyes scared us out. We did not care to put them at bay. The next day I rowed out to the _Laughing Lass_ and got a rifle. I found the captain asleep in his bunk, and did not disturb him. Perdosa and I, with infinite pains, tracked and stalked the sheep, of which I killed one. We found the mutton excellent. The hunting was difficult, and the quarry, as time went on, more and more suspicious, but henceforward we did not lack for fresh meat. Furthermore we soon discovered that fine trolling was to be had outside the reef. We rigged a sail for the extra dory, and spent much of our time at the sport. I do not know the names of the fish. They were very gamy indeed, and ran from five to an indeterminate number of pounds in weight. Above fifty pounds our light tackle parted, so we had no means of knowing how large they may have been.

Thus we spent very pleasantly the greater part of two weeks. At the end of that time I made up my mind that i............