What is he doing here? He drives his boat over the black looking-glass of the lake; round and round he goes, searching the black walls with anxiety, his lamp raised in his disengaged hand. Does he imagine that a secret is hidden there? Does he think that by touching a spring, and saying "Open Sesame," the treasure hidden there for hundreds of years will spring forth? In truth, he does find treasures. Here and there from the black wall-weakly constructed in some places by Nature's hand-a piece of stone loosens itself-upon it the impression of a leaf belonging to a long-ago-extinct species. A wonderful treasure this! In other places he comes upon unknown crystals, to which science has not as yet given a name; or upon a new conglomeration of different quartz, metal, and stone-a silent testimony to a convulsion of Nature before this world was. All these witnesses speak. The pillars, too; over them the water of the pond has by degrees formed a crustation of crystals, small, but visible even without a glass. This, too, gives testimony. The pond is in itself wonderful.