FORMATION OP NATURAL SOILS. 13 



land, and a warm, humid, and tropical atmosphere in those islands. The grand 

 sigillaria and stigmaria, and the arborescent ferns, were the typical vegeta- 

 tion, and ever3'tbing announces an epoch of immense duration. Professor 

 Phillips calculates that at the present rate of progress, 122,400 years would be 

 required for the accumulation of 60 feet of coal ; while the formation in some 

 places is supposed to be upwards of 2,000. It is supposed that, in the upper 

 coal-fields, where bed is heaped upon bed, the produce of ages upon ages, their 

 formation was quiet and progressive ; but that towards the end of the period 

 it was marked by great convulsions ; the ma-ses of coal were broken, and 

 thrown down in dislocated lines into separate basins, during which we enter 

 on a fourth geological epoch : — 



27. IV. The Permian system has left few traces in the British islands. It 

 is, however, represented in Yorkshire, Derbyshire, and some other places, by 

 accumulations of dolomite, of which we have examples in the stone used for 

 the new Houses of Parliament. The mountains of the S3-stem attain great 

 height, but they are poor in fossils. Various-coloured marls, sandstone, and 

 magnesian limestone, characterize the formations of this epoch ; it is a transi- 

 tion period, closing a chapter in the history of the creation, during which the 

 British islands emerged from the gi-eat deep, while the inhabitants of the seas, 

 or at least their remains, were elevated to the summits of the highest 

 mountains in some grand convulsion of nature. 



28. V. The New Red Sandstone is the commencement of a second phase in the 

 geological formation of these islands. In its features it is neither so striking 

 as the old red sandstone, nor has it the bold and rigid aspect of the more 

 primitive granite rocks. It furnishes, however, materials of the highest im- 

 portance to industrial art. Many of our feudal castles and ruined abbeys were 

 constructed out of its quarries. Its masses have formed the sandy bed of an 

 ancient sea, of less depth than the seas of the preceding epochs ; for the traces 

 left by the feet of an animal of the tortoise kind, of gigantic size, in its daily 

 visits to the seashore, have been clearly traced in this formation. 



29. VI. The Oolite formation originates in the muddy deposit made in a calm 

 sea. In the grand masses of rock of which it consists, were found the ichthyo- 

 saurus and other gigantic animals of wonderful structure — dragons of fearful 

 foiTn, which the imagination of man had failed to characterize. From York- 

 shire on the north-east, to Dorsetshire on the south-west, this formation extends 

 across England, a system of rocks nearly 30 miles in breadth, which give a 

 peculiar profile to the country. The slopes are gentle, as compared with any 

 of the previous formations ; the valleys are intersected by brooks and small 

 rivers, and clothed in richest vegetation ; but the landscape is tame as com- 

 ]pared with that of the limestone or sandstone mountains. The scenery no 

 longer surprises, it only pleases ; and its quarries furnish a beautiful building 

 material, as in the Bath and Portland stone. 



30. The isle of Portland, off the Dorset coast, rises to a considerable height 

 above the level of the sea, and presents, on the side of the port, a perfect 

 citadel of reefs ; on the west a line of round pebbles, flints, and moveable 



