The same principles which have been pursued in the previous pages in elucidating the history of the Carboniferous system, will conduct the reader to the true origin and age of any group of rocks he may encounter, whatever its nature, and wheresoever its locality. Let him, therefore, in his country rambles, seek to verify them in valley and hill-side, by lake and cataract, and along river-course and sea-shore. Let him not be content with simply admiring the picturesque grouping of rock-masses, but rather seek to interpret their origin and history, tracing them step by step into the past, amid ages long prior to man. Such a process will give him a yet keener relish for the beauties of their scenery, by ever calling up to his mind some of those striking contrasts with which geology abounds. In the stillness of the mountain-glen, he will see on every side traces of the waves of ocean, and when dipping his oars into the unruffled sea among groups of wasted rocks, miles from shore, he will bethink him, perchance, of some old forest-covered land, of which these battered islets are the sole memorials. His enjoyment of the scenery of nature is thus increased manifold, and he carries about with him a power of making even the tamest landscape interesting. Cowper, in one of his exquisite letters, remarks,--"Everything I see in the fields, is to me an object; and I can look at the same rivulet or at a handsome tree, every day of my life, with new pleasure." Had the sweet singer of Olney lived to witness the results obtained by the geologists whom he satirized, he would perhaps have sauntered along the Ouse with a new pleasure, and have felt a yet more intense delight in casting his eyes athwart the breadth of landscape that spreads out around-the "Peasant's nest."