Then climbing over an assortment of bowlders of all sizes, going up a little, and swinging or sliding down, we came to a point in the narrow passage where the floor is a flat slab, like a large paving stone, tilted up at a steep angle against one wall and not reaching the other by about fifteen inches, with darkness of unknown depth below: about three feet above this opening the wall projects in a narrow, shelving ledge, and everything is covered with a thin coating of slippery wet clay. The only way to cross that uninviting bridge is to brace the feet against the slab, and leaning on the ledge, slowly work across. A little more rough work and the descent of the two short ladders, brought us, at last, under the beautiful Waterfall, where we stood as in a heavy shower of rain at the lowest point yet reached in the cave, which according to the survey of Mr. Prince is four hundred feet below the surface. The falling water has ornamented the walls, which in this portion of the cave expose over two hundred feet of Magnesian Limestone, with unique forms of dripstone; and the steeply sloping floor has received the over-charge of calcium carbonate until it has become a shining mass of onyx, retaining pools of cold, transparent water in the depressions. In the lowest corner there is only mud, and above it rises, to a height of at least fifteen feet a bank of miry, yellow clay, at the top of which a hole in the wall is the only known entrance to Blondy's Throne. [Illustration: Longitudinal and Cross-Sections of Passages in Marble Cave, Stone Co., Missouri. Plotted by Fred Prince, 1894.] CHAPTER III. MARBLE CAVE CONTINUED.