There are also in some places domes hollowed out. In Glen Cañon of the Colorado, a little below the mouth of the San Juan, is a dome of this character carved out of the homogeneous sandstone by the action of a pretty brook, which in fair weather is a mere rivulet, but in rain time is an angry flood, sweeping down on its tide immense quantities of sand. This little stream enters at the back of the cavern through a very deep, narrow cleft, not more than a foot or two wide, and after a plunge of some thirty feet or more into a clear pool trickles on out to the river, which flows past the entrance. The chamber is about two hundred feet high, with a narrow crevice twisting on up to the top of the cliffs, about a thousand feet, while the area of the sandy floor is about two hundred by five hundred. Its mouth is barred by a little grove of box-elder trees. When the storm is abroad the innocent brook grows to a giant in an hour, because of the rain accumulating on the barren, rock-surfaced country as on the roof of a house, and, gathering the load of sand in its impetuous clutch, it hurls it against the bounding walls, thus doing its part in the war of the waters against the land. I have counted dozens of these cascades leaping over the cañon walls during heavy rainstorms. An exploring party once camped within the dome mentioned, and, thinking it rendered well their songs, they named it "Music Temple." Some carved their names on the soft sandstone wall, and three of these a short time after were sent by the Indians to the Great Dome of all. [Illustration: FIG. 7.--TENNYSON'S MONUMENT.] The extensive Pink Cliffs, forming the escarpment of the southern edge of the Great Basin, are of the colonnade type, and for many miles their exquisite color and massive columnar façades crown the high country ten thousand feet or more above the sea, visible far to southward, and with the underlying Gray Cliffs and the still lower down Vermilion Cliffs (which find their beginning in Glen Cañon of the Colorado, and trace their serpentine line leagues to the west to meet the Temples of the Virgin) form one of the most magnificent panoramas to be found anywhere in the world. Detached and isolated portions of these Pink Cliffs, surrounded by the upper members of the Gray, produce sometimes novel effects. I recall one sunny morning when I found myself suddenly in a silent grassy glade, green and gray all round, with before me what can be likened only to an immense pipe organ, its delicate pink columnar pipes standing full two hundred feet high against a somber background of pines where Æolus could be heard sighing for the lost chord. [Illustration: FIG. 8.--TEMPLES OF THE VIRGIN.]