that is far distant. And Geologists do not fail to make use of this important conclusion when they find the animal and vegetable remains of different climates associated together in the same strata of the Earth. [Illustration] [Illustration] _CHAPTER IV._ THEORY OF DENUDATION--CONCLUDED. _Glaciers--Their nature and composition--Their unceasing motion--Powerful agents of denudation--Icebergs--Their number and size--Erratic blocks and loose gravel spread out over mountains, plains, and valleys, at the bottom of the sea--Characteristic marks of moving ice--Evidence of ancient glacial action--Illustrations from the Alps--From the mountains of the Jura--Theory applied to northern Europe--To Scotland, Wales, and Ireland--The fact of denudation established--Summary of the evidence--This fact the first step in geological theory._ The next agent of Denudation to which we invite the attention of our readers, is one of which our own country affords us no example, but which may be seen in full operation amidst the wild and impressive scenery of Switzerland. And we know not how we can better introduce the subject than by the solemn address of a great poet, in whom an ardent love of nature was blended with a deep sense of religion. As he stood in the midst of the snow-clad mountains that shut in the valley of Chamouni, his spirit, “expanded by the genius of the spot,” soared away from the scenes before him to the Great Invisible Author of all that is beautiful and sublime in nature, and he poured forth that well-known hymn of praise and worship in which he thus apostrophizes the massive glaciers of Mont Blanc:-- “Ye ice-falls! ye that from the mountain’s brow Adown enormous ravines slope amain-- Torrents, methinks, that heard a mighty voice, And stopped at once amid their maddest plunge! Motionless torrents! silent cataracts! Who made you glorious as the gates of Heaven Beneath the keen full moon? Who bade the sun Clothe you with rainbows? Who with living flowers Of loveliest blue, spread garlands at your feet? God! let the torrents, like a shout of nations, Answer! and let the ice-plains echo, God! God! sing ye meadow-streams with gladsome voice! Ye pine-groves, with your soft and soul-like sounds! And they too have a voice, yon piles of snow, And in their perilous fall shall thunder, God!”[29]