The celebrated cascade of Regla is just behind the hacienda. There is a sort of basin, enclosed on three sides by a perpendicular wall of basaltic columns, some eighty feet high. On the side opposite the opening, a mountain stream has cut a deep notch in this wall, and pours down in a cascade. The basaltic pillars rest upon an undisturbed layer of basaltic conglomerate five feet thick, and that upon a bed of clay. The place is very picturesque; and two great Yuccas which project over the waterfall, crowned with their star-like tufts of pointed leaves, have a strange effect. These basalt-columns are very regular, with from five to eight sides; and are almost black in colour. They have a curiously well-defined circular core in the middle, five or six inches in diameter. This core is light grey, almost white. The Indians bring down numbers of short lengths or joints of the columns, and they are used at the hacienda in making a primitive kind of ore-crushing mill, in which they are dragged round and round by mule-power, on a floor also of basalt. When we had visited the falls we took leave of our hospitable friend, and set off to return to the Real. We stopped at San Miguel, another of the haciendas of the Company, where the German barrel-process is worked. Just behind the hacienda is the Ojo de Agua—the Eye of Water—a beautiful basin, surrounded by a green sward and a wood of oaks and fir-trees. A little stream takes its rise from the spring which bubbles up into this basin, and the name “Ojo de Agua,” is a general term applied to such fountain-heads. When one looks down from a high hill upon one of these Eyes of Water, one sees how the name came to be given, and indeed, the idiom is thousands of years older than the Spanish tongue, and belongs as well to the Hebrew and Arabic. A Mexican calls a lake _atezcatl_, Water-Mirror, an expressive word, which reminds one of the German _Wasserspiegel_.