They now pulled, as before, in silence, using all their strength. The head of the boat was almost up stream, and as they pulled they could see all that could be seen of the danger below them. For about five minutes they thus struggled, and at the end of that time there began to force itself into the minds of both of them the dread conviction that the strength of the current was too great for their efforts. Pat saw this first, and, seeing this, made a final relinquishment of his efforts to cross, and put the boat’s head straight up stream, so as to make all their efforts tell against the tide itself. But by that time they had brought themselves to where the tide was strongest, and that tide was growing stronger and stronger every minute. This they both saw and felt; and they knew enough of the nature of the Falls to understand now the mistake that they had made. For they had crossed to the islands when the tide was falling, and, in their attempt to return, had been caught by a tide that had been increasing in force ever since they had last crossed it, and was still increasing and directing all its might down towards the Falls. Their efforts to resist the tide were overpowered. The river was gaining; their strength was failing. One last, faint hope remained--to turn the boat back, to pull towards the islands; it might yet be possible by strenuous effort to drag the boat forth from the clutch of the mighty waters. The lower island was as yet below them, on their left; if they could only bring the boat out of the middle of the stream, they might reach it. For the last time, then, Pat changed the direction of the boat, turning it but slightly, however, just enough to aim at the upper island. Then again, as before, they put forth their last remaining energies. With feverish anxiety they fixed their eyes upon one or two objects on the land, to watch whether the boat was losing or gaining. That it was still being drawn down by the tide was at once certain; but they yet had a hope that their advance towards the islands might serve to bring them there before it was too late. And now they had fairly reached the crisis of this tremendous struggle. Rousing up the very last of their exhausted strength, they exerted themselves with the convulsive energies of despair, working in silence, with eyes fixed on the shore. In vain! They saw themselves drawn down in a line with the lower island, and there, tree by tree, and rock by rock, they saw that island slipping past them; while the distance between them and it had been lessened so slightly that it afforded no prospect whatever of their being able to attain it. At length the last vestige of hope died out. The howling, wrathful vortex was just before them, and now the islands were forgotten, and all their efforts were directed towards saving themselves as long as possible from that fate which they felt was inevitable.