low, in his Missouri Geological Survey Reports I. and II., 1853 and 1854, says: "Caves, natural bridges and subterranean streams occur in the valley of the Osage and its tributaries." The same authority of forty years ago also mentions that "Some of the grandest scenery in the State is produced by the high castellated and mural bluffs of this (Third Magnesian Limestone) Formation, on the Niangua and the Osage." Another reference to the scenery on these rivers describes it as "Wild and grand, beautiful and unique;" with "gaudy-colored bluffs." In the section on building materials he remarks: "One of the most desirable of the Missouri marbles is in the Third Magnesian Limestone on the Niangua. It is fine-grained, crystalline, silico-magnesian limestone of a light drab, slightly tinged with peach-blossom, and beautifully clouded with the same hue or flesh color. It is twenty feet thick and crops out in the bluffs. This marble is rarely surpassed in the qualities which fit it for ornamental architecture."