She saw that these rocks, like the bar of a river, crossed the inlet of the cove; but she had not been told of their peculiar frame and upshot, which made them so treacherous a rampart.

At the mouth of the bay they formed a level crescent, as even as a set of good teeth, against the sea, with a slope of sand running up to their outer front, but a deep and long pit inside of them.

This pit drained itself very nearly dry when the sea went away from it, through some stony tubes which only worked one way, by the closure of their mouths when the tide returned; so that the volume of the deep sometimes, with tide and wind behind it, leaped over the brim into the pit, with tenfold the roar, a thousandfold the power, and scarcely less than the speed, of a lion.
Mary Anerley thought what a lovely place it was, so deep and secluded from anybody's sight, and full of bright wet colors.

Her pony refused, with his usual wisdom, to be dragged to the bottom of the hole, but she made him come further down than he thought just, and pegged him by the bridle there.

He looked at her sadly, and with half a mind to expostulate more forcibly, but getting no glimpse of the sea where he stood, he thought it as well to put up with it; and presently he snorted out a tribe of little creatures, which puzzled him and took up his attention.
Meanwhile Mary was not only puzzled, but delighted beyond description.
She never yet had come upon such treasures of the sea, and she scarcely knew what to lay hands upon first.