Twice more Dick spoke to his father about coming, for Josh was muttering very sourly, and seemed disposed to resent this hanging back when he suggested that it would be better to go; but Mr Temple was so deeply interested in his discovery of what seemed to be a promising and, as far as he could for the moment tell, absolutely a new vein, that he forgot everything else in his intense desire to break off as good a specimen of the rock as he could. "There," he said at last in a tone of triumph, "I think that will do. Steady, Dick, take these pieces. Now, you, my lad, go forward to your place. We'll hold the lanthorn, and--why, how's this? the ceiling seems to be lower." "But it aren't," growled Josh sourly; "it's the gashly tide come in. There," he said, as he thrust the boat round an angle which had hidden the entrance of the cavern, "the boat won't go through there." "Through there?" cried Mr Temple, as Dick felt his heart sink at the sight of the little archway in the rock not a foot above the surface of the water and sometimes with that surface going closer still towards the rugged crown of the natural arch. "Well, there aren't no other way," said Josh, whose long sleep had been the cause of the mishap, for had he been awake he would have known that they were staying longer than was safe. "But," cried Mr Temple, who felt alarmed now on account of his boys and their companions, "what are we to do? We must leave the boat and wade out." "Wade!" growled Josh. "Why, there's three fathom o' water under where we sit." "Then we must swim through," cried Mr Temple excitedly. "There is no time to spare. Man, man, why did you not warn us of the danger?" "Why--why?" growled Josh. "I didn't know. I never see the tide come up that gashly way afore." "It was while you were asleep, Josh," said Dick in a whisper; and Josh turned upon him as if he had been stung. "Now," cried Mr Temple, as he pointed to the low opening through which was the sunshiny sea and safety, while on their side was apparently darkness and death; "now, Dick, you can swim through there; but first try whether by lying down we can force the boat under." "Oh, I'll try!" said Josh; "but it's of no use, not a bit of use. Be it, Will?" "No," said the latter decidedly, as he and Josh urged the boat right up to the entrance, and Mr Temple saw at once that it would be an impossibility. "Then we must swim," said Mr Temple. "You can swim that, Dick?" "Yes, father," said Dick. "Clothes and all." "Yes, of course, the distance is so short." "And you, Arthur, you can swim through there?" The boy could not speak, for he was battling down the horrible feeling of dread that came over him. "I say, you can swim that, Arthur?" said Mr Temple sternly. "Yes, father. I'll try," said the boy quickly. "That's well. Of course you two can swim?"