Every Winter, with its frost and its storing up of moisture in the great snow-fields of the mountains, is a benefit to the lands and their people, but the Ice Age, "The Winter that Lasted All Summer,"[33] not only worked wonders in other ways, but was of far greater benefit to the soil because it was so much more of a Winter. [33] "The Strange Adventures of a Pebble." Mr. Shakespere, in his day, didn't know anything about an Ice Age, but Brer Bear might have quoted certain lines of his, just the same: "Blow, blow, thou winter wind, Thou art not so unkind As man's ingratitude. Freeze, freeze, thou bitter sky, Thou dost not bite so nigh As benefits forgot."[34] [34] "As You Like It." [Illustration: _Courtesy of the Northern Pacific Railway_ ASTER GROWING IN VOLCANIC ASH ON MT. RANIER] THE GREAT PLOUGHS OF THE ICE AGES With all the work the other agencies do in changing the rock into soil, and fertilizing and refreshing it with additions from the subsoil, there still remains an important thing to be done, and that is to mix the soil from different kinds of rock. This is still done constantly by the winds and flowing waters, but every so often, apparently, there needs to be a deeper, wider stirring and mixing. This the great ice ploughs and glacial rivers of the Ice Ages did. And they do it every so often, probably; for there was more than one Ice Age in the past, and, as Nature's processes do not change, it is more than likely there will be more ice ages and more deep ploughing and redistribution of the soil in the future. As you will see, if you take the trouble to look it up in "The Strange Adventures of a Pebble," it is thought we may now be in the springtime of one of those vaster changes which bring Springs lasting for ages, followed by long Summers and Autumns, and by the age-long Winters and the big glaciers and all. [Illustration: HOW THE MOUNTAINS FEED THE PLAINS "The elevations of the earth's surface provide for it a perpetual renovation. The higher mountains suffer their summits to be broken into fragments and to be cast down in sheets of massy rock, full of every substance necessary for the nourishment of plants, and each filtering thread of summer rain is bearing its own appointed burden of earth to be thrown down on the dingles below."]