But what does the sea do with the harder parts of the cliff? Its waves wear away the rock on each side and leave one or more long fingers reaching out into the sea. The wear and tear on such a projection is immense. A strong swimmer may play with the breakers away from the cliff. At exactly the right moment he may dive headlong through the pearly green Niagara that has not yet fallen quite to his head and may sport in the comparatively quiet water beyond, while the wild ruin falls with a sound of thunder on the beach. But let him once be caught and dashed against the rocks and there is no more life or wholeness of bones within him. In the swirl of converging currents between two rocky projections, as the coarse sand and gravel is surged around a few hundred thousand times, there is a great tendency to wear through the wall of the projecting finger. It is often done. Illustration No. 4 shows at low tide such a projection cut through. Since the picture was taken the bridge has fallen, the detritus been carted away by the waves, and the pier stands lonely in the sea. [Illustration: An Excavated Arch, Santa Cruz, Cal.] No. 5 shows one bridge exceedingly frail and another more substantial nearer the famous Cliff Drive. I go to the frail one every year with anxiety lest I shall find it has been carried away. How I wish I could show my readers the delicate sculpture and carving further back, nearer yet to the drive. But note the various strata, the rocks worn to a point as even the milder waves run over them; note the cracks that tell of the awful push and stress of the titanic struggle. [Illustration: A Double Natural Arch, Santa Cruz, Cal.] Illustration No. 6 shows three such under-hewn arches. The long projection of rock is so curved as to prevent the arches being fully seen in any one view. I have waded and swam through these rocky vistas, and there, where any more than moderate waves would have mangled me against the tusks of the cruel rocks, I have found little specimens of aquatic life by the millions, clinging fast to the rocks that were home to them and protecting themselves by taking lime out of the water and building such a solid wall of shell that no fierceness of the wildest storm could work them harm. All these seek their food from Him who feeds all life, and he heaves the ocean up to their mouths that they may drink. [Illustration: A Triple Natural Arch, Santa Cruz, Cal.] No. 7 shows what has been a quadruple arch, only one part of which is still standing. Out in the sea, lonely and by itself, appears a pier, scarcely emergent from the waves, which once supported an arch parallel to the one now standing and also one at right angles to the shore. The one now standing makes the fourth. But the ever-working sea carves and carries away arch and shore alike. At some points a careful and even admiring observer sees little change for years, but the remorseless tooth gnaws on unceasingly.