On the fourth was a strip of beach and a cleft through which poured a plume-like waterfall white as a wreath of driven snow.
"Did we come in that way ?" asked Cabot, pointing to this torrent of silver spray.
"I suppose we must have," rejoined White soberly; "for I can't see any other opening, and it certainly felt last night as though we were sailing over the brink of a dozen waterfalls.

But let's get breakfast, for I'm as hungry as a wolf.

Then there'll be time enough to find out how we got in here, as well as how we are to get out again." After a hearty meal they got the dinghy overboard and started on a tour of exploration.

First they visited the beach and found a rude pathway leading up beside the waterfall that promised exit from the basin to an active climber.
"In spite of all the wonderful happenings of last night I don't believe we came in that way," said Cabot.
"No," laughed White, "the old 'Bee's' wings aren't quite strong enough for that yet, though there's no saying what she may do with practice." Satisfied that there was no outlet for a sailing craft in this direction, they pulled towards the opposite side of the basin, but not until they were within a few rods of its cliffs did they discover an opening which was so black with shadow that it had heretofore escaped their notice.
"Here it is," cried Cabot, "though----" His speech was cut suddenly short, and for a moment he stared in silent amazement.

The farther end of the passage was completely filled by what appeared a gigantic mass of white rock.
"An iceberg!" exclaimed the young skipper, who was the first to recognise the true nature of the obstacle.