The spot where the explosives had been buried was in a grove, a short distance from a little bay, which was enclosed on either hand by tall cliffs, and inaccessible from the rest of the lagoon except by means of a boat, unless a path was cut inland through the dense scrub, which apparently had never yet been penetrated by human beings. The taller of the two cliffs was almost divided from base to summit by the curiously shaped cave which Old Humphrey had laid particular stress upon in his log, and directly the boat touched the sandy beach I bounded off towards it on my trip of exploration, a final warning from my uncle falling lightly upon my ears. A heap of loose boulders, which had fallen during the shock, encumbered the mouth of the cave; but these I easily surmounted, and advanced cautiously over the smooth floor, my eyes dim by the sudden change from the brilliant sunshine to the subdued light of the cavern. The walls were composed of blocks of basalt, the general regularity of the vertical shafts broken here and there by gaping horizontal and diagonal fissures, while at intervals a thin stream of water fell from the roof with a cool and pleasing sound. As I proceeded the roof gradually became lower, till, just as the daylight failed, its height was less than twenty feet. Taking the ball of twine out of my pocket, I made fast one end to a projecting ledge. The candles, I found, had united into a soft bent stick of wax by reason of the heat of the sun, but, straightening them out and cooling them in a pool of water, I had a double-wicked torch in place of the two candles. As I went on, making a careful survey of the ground for fear of pitfalls, I noticed that on either hand numerous side passages branched out, some large, some small; but, keeping as straight a direction as I could, I advanced slowly, paying out the twine as I went. At length the smooth floor gave place to a ridge of rock, about four feet in height, leaving an opening of barely three feet between it and the roof. Here I stopped, debating with myself whether it would be wiser to retrace my way, but a feeling of uncontrollable curiosity urged me to continue my investigations. Having unrolled a length of twine, I threw the ball over the barrier. Having one hand free, I began to clamber over the ridge, holding the lighted candle carefully in my left hand. Beyond I could see that the floor was even, though higher than on the side which I had left, so I unhesitatingly slipped down the opposite slope of the rock and gained the interior of the inner cave.