A beck, or stream of water, was, indeed, a valuable discovery; and, conducted by Ruth, Arthur and Jack forced their way through entangled roots and brushwood, till they reached a narrow rivulet of clear water, probably flowing from the lake by some unseen channel beneath the grassy region they had crossed; and after trickling down the rocks, it again disappeared in the sand and shingles of the beach.
"This is but a slender supply, Jack," said Arthur; "I fear it might fail us in a drought."
"We must dig a tank, Mr. Arthur," he answered; "that is, if we can raise a spade."
Jack considered for a few minutes. He was not to be checked by apparent difficulties in his undertakings. "What do you think, Mr. Arthur, of one of those big oyster or mussel shells? I could tie one to a stick with some of these stringy fibres of creeping plants; or, better far, there's a tree up above, that seems to have a bark you might ravel out into strings; and there's another tree, with a stiff, regular sort of gum, as good as glue, oozing out of it. Now, with all these, I'll be bound to make a spade or two that will turn up this light soil fast enough."
"Then the sooner we set about it the better, Jack," answered Arthur. "We cannot do better than remain in this spot, if we meet with no disturbance, until we can make some canoe or raft to take us off; and it is absolutely necessary to secure a supply of water. Let us go and choose our shells."
But when they returned to the beach, they found Mr. Mayburn so much overcome by the scorching heat of the sun, that their first care was to get up a tent or shelter of some kind for him. They selected a deep niche in the cliff, where the rocks formed a complete angle, and having procured from the wreck some suitable spars, they fixed them in the crevices of the rocks, to form the rafters of the roof, which they covered with the long grass which grew above the cliffs. The sail was thrown over the front, as a curtain, and they were thus provided with a shady and convenient apartment.
At low tide, Hugh and Gerald amused themselves with searching for nests in the extremity of the promontory, and finding an opening, they had penetrated into a spacious cave, the mouth of which would be covered at high-water; but as it shelved upwards to a considerable distance in the rocks, the back part was safe and dry.
"Just think, Hugh, my boy," said O'Brien, "what a fortress this would be for us if we were invaded. One man could defend the entrance with the gun, even at low-water; and how we should defy the rogues when the tide was up."
"But it would be horribly dismal, Gerald," answered Hugh. "We could never bear to live in it long; and, you know, we need no sleeping-rooms or houses to cover us in this fine climate; so we will leave it uninhabited, at least in peaceful times. But we will show it to Arthur, and ask him if it would not make a good storehouse."
Arthur congratulated the boys on their discovery, and the timid father was highly gratified at the thoughts of such a secure retreat; after he had satisfactorily ascertained that it could always be accessible at low-water, and never dangerous at the highest tide; and Margaret proposed that the cookery should be accomplished within the cave, that the smoke might not attract the observation of the dreaded natives. So Jenny established her kitchen here, and prepared an excellent dinner of fish, and potatoes boiled in the shells of the turtle, while Margaret kept watch for the returning tide, though Jenny said, "It's all little use, Miss Marget; it has to be, I feel. Ruth's sartain to be catched and fastened up in this eerie place."