Water might have been obtained also in another way. The country on both sides of the river at this point is composed chiefly of barren surfaces of homogeneous sandstone which collect enormous quantities of water, like the roof of a house, during rain-storms, and pour it over the edges of the cliffs and down the alcoves and lateral canyons. This water may also have been utilised for irrigating purposes. The Mokis utilise showers by collecting and guiding the streamlets with low dams hastily thrown up by their hoes, so it is certain that all these Amerinds understood thoroughly the importance of utilising shower-water on their crops.[297] [Illustration: SO-CALLED ELEPHANT MOUND, WISCONSIN Has been ploughed over. Length, 140 ft.; greatest height, 4 ft. ] [Illustration: ANCIENT FABRIC DESIGN FROM IMPRESSION ON POTTERY, UTAH] In the Verde River region of Arizona some very large canals or “ditches” have been observed. Mindeleff has described a number of these, and I will mention one which he says is one of the finest he has seen.[298] This is “about two miles below the mouth of Limestone Creek on the opposite or eastern side of the river.” The canal extends across the northern and western part of an extent of fertile bottom land. In one place it is marked “by a very shallow trough in the grass-covered bottom, bounded on either side by a low ridge of earth and pebbles, at another it was cut through a low ridge. It is probable that the water was taken out of the river about two miles above this place, but the ditch was run on the sloping side of the mesa which has recently washed out.” It is supposed that this ancient canal irrigated nearly the whole of the bottom land mentioned, which was recently again reclaimed by another “ditch” or canal constructed by Americans. “The ancient ditch is well marked by two clearly defined lines of pebbles and small boulders.... Probably these pebbles entered into its construction, as the modern ditch, washed out at its head ... shows no trace of a similar marking.” [Illustration: ANCIENT FABRIC PRESERVED BY COPPER CELT, IOWA See page 108 ]