6lO DENUDATION AND SCENERY. 



in length, breadth, and inclination. Rarely the strips stretch across the hills, as 

 indicated by hedgerows still remaining near Walditch ; but in other cases, where 

 no hedgerows exist and the land has been turned into permanent pasture, the 

 slopes present the features of linchets. In the Isle of Purbeck, near Langton and 

 Worth (see Fig. loo), also near Abbotsbury, many linchets occur. 



On Portland the soil in some parts is now cultivated in narrow strips ; thus in the 

 space of a quarter of a mile, north of the Higher Lighthouse, there were in 1884, 

 thirty-five strips of land, averaging twelve yards in width, but some only six yards, 

 on which corn, grass, potatoes, etc., were grown. In other places as near Rugby, 

 where ploughed land has been converted into pasture, the ridges between the 

 master-furrows have become more prominent by the action of moles, etc. 



Our country, as we have seen, contains probably a fuller record 

 of the earth's history than any other tract of land of equal extent. 

 Had not such a series of changes taken place, it is unlikely that 

 so many useful kinds of building-stone and clay, that so much 

 wealth of coal, of metalliferous deposits, and other natural pro- 

 ducts, would have been furnished out of about sixty so-called 

 elementary substances. To these facts no doubt our country in 

 part owes its position among the nations ; while by its isolation, 

 and by the erosion of its coast-line, resulting in so many natural 

 harbours, great advantages have also been gained. 



The diversity of scenery, unsurpassed in this respect by any 

 other region, is itself a result of the physical changes we have 

 attempted to describe, and when we proceed to picture the many 

 scenes that our tract of land has witnessed in the past, we find 

 their counterparts in all climes and conditions of the present. 

 Volcanoes, Glaciers, Coral Reefs, huge Lakes and Rivers, have all 

 played their parts in the history ; and the rocks and fossils, the 

 varied forms of hill and dale, remain as monuments of these 

 changes. Moreover, not the least interesting branch of the subject 

 is to compare the forms of life now existing in distant portions of 

 the world, with those found in different formations, and to trace 

 in the present seas and oceans, and on the present conti- 

 nental areas and islands, lingering types of successive ages in 

 the past. 



In certain Boulder Clays and Gravels we find the relics of 

 conditions similar to those affecting Greenland and Labrador at 

 the present day. We may picture tropical and subtropical sur- 

 roundings in our Eocene strata. We have but to go into a Chalk- 

 pit to study the conditions of the deepest ocean-bed. In the 

 freestone quarries of the Oolitic hills we sometimes find the 

 evidence of old coral reefs, and many of the organic remains 

 forcibly ren:iind us of the existing flora and fauna of Australia. If 

 we turn to the Red cliffs of Dawlish and Teignmouth, or to the 

 salt-mines of Cheshire, the scene changes to large lakes such as 

 the Caspian and Aral — lakes formerly connected with the sea. 

 Again, we can study sub-tropical vegetation in the heaps of refuse 

 thrown out from our Coal-mines ; whilst in still earlier periods we 

 find that the scene constantly changes — the secretions of the Coral 

 polype, the sands of the sea-shore, the sediment formed in lakes, 

 and the lava and ashes of volcanoes, all form part of our Welsh 

 and Cumberland mountains ; and when we clamber over these 



