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The scenery of Scotland veiwed in connection with its physical geology
The scenery of Scotland veiwed in connection with its physical geology Author:Archibald Geikie Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER II Nature's Sculpture-tools—Air, Rain, Rivers, Springs, Frost The process by which the scenery of a country is produced may be compared to sculptu... more »re. In the fashioning of a statue, the block of stone must f1rst be lifted out of its bed in the parent rock, before the sculptor's tools can be used upon it. Apart from the design and workmanship, the aspect of the statue will primarily depend on the nature of the material employed. Long practice has shown that statuary marble is best adapted for the purpose of the sculptor's art. If conglomerate, or sandstone, or porphyry, or granite were chosen, the effect would in each case be different. So in the case of the dry land. There must first be an uplifting of the ground above sea-level, and then Nature's tools will slowly carve its surface into the characteristic terrestrial shapes. The ultimate details of these shapes will be greatly influenced by the nature of the material, each kind of rock revealing its own peculiar characters and influence in the general process of land-sculpture. But much also will depend upon the particular tools which Nature may use, and on the energy with which she wields them. The tools that have been most effective in the carving of the land are Air, Rain, Frost, Springs, Rivers, Glaciers, and the Sea. Let us watch each of them at work. Air And Rain Long exposure to the air tells even upon the most obdurate kind of stone. An old building always shows more or less manifest proofs of decay, insomuch that if these are not conspicuous, we instinctively begin to doubt whether it can really be old. This decay is known by the name of " weathering." It is a complex process, partly chemical, partly mechanical. Great and rapid changes of temperature tell powerfully upon the outer surfaces of rocks. H...« less