2r)0 MOOR-LANDS OF THE MILLSTONE GRIT. 



of the low country of Northumberland, is covered with these measures -but 

 tli8 largest area covered by these rocks is in that part of the low country of 

 Scotland which extends in a north-easterly direction from the west coast of 

 Ayrshire to the eastern coast of Fife, They there form a broad band, having 

 an average breadth of 30 miles, interrupted often by trap or green-stone rocks, 

 yet lying immediately beneath the loose superficial matter, over the largest por- 

 tion of this extensive district. They do not occur further north in our island. In 

 Ireland they form a tract of limited extent on the northern borders of the county 

 of Monaghan — cover a much larger area in the south-east in Kilkenny and 

 Clueen's counties — and towards the mouth of the Shannon, spread on either 

 bank over a large portion of the counties of Clare, Kerry, and Limerick. 



Soil. — The soil produced by the degradation of the sand-stones and shales 

 of the coal formation is universally of inferior quality. The black shales or 

 schists form alone a cold, stiff, ungrateful clay. The sand-stones alone form 

 thin, unproductive soils, or barren — almost naked — heaths. When the clay 

 and sand are mixed a looser soil is produced, which, by heavy liming, by drain- 

 ing, and by skilful culture, may be rendered moderately productive. In the 

 west of the counties of Durham and Northumberland, and on the higher edges 

 of most of our coal fields, there are extensive tracts of this worthless sand-stone 

 surface, and thousands of acres of the improveable cold clays of the shale beds 

 These latter soils appear very unpromising, and can only be rendered remune- 

 ratively productive in skilful hands. They present one of those cases in which 

 the active exertions of zealous agriculturists, and the efforts of the friends of 

 agriculture, might be expended with the promise of much benefit to the country. 



16°. Millstone Grit. 600 ft. This formation consists in some lo- 



calities of an entire mass of coarse sand- 

 ^1^ stone, of great thickness — in others of 



'^ alternations of sand-stones and shales, 



resembling those of the coal-measures 

 — while in others, again, lime-stones, 

 more or less siliceous, are interposed 

 among the sand- stones and shales. 

 Extent. — A large portion of Devonshire is covered with these rocks — they 

 form also the high land which skirts to the north and west the coal-measures of 

 Yorkshire, Lancashire, and Durham, and over which is the first ascent to the 

 chain of mountains that run northward through these three counties. In Scot- 

 land, they have not been observed to lie immediately beneath any part of the sur- 

 face. In the north of Ireland they cover a considerable area, stretching across 

 the county of Leitrim between Sligo and Lough Erne. 



Soil,— The soils resting upon, and formed from, these rocks are generally of 

 a very inferior description. Where the sand-stones come to the surface, miles 

 of naked rock appear; other tracts bear only heath, or, where the rains have 

 only a partial outlet, accumulations of peat. The shale-beds, like those of the 

 coal-measures, afford a cold, unproductive, yet not unimproveable soil — it is 

 only where lime-stones occur among them that patches of healthy verdure are 

 seen, and fields which are readily susceptible of profitable arable culture. 



It is true, therefore, of this formation in general, that the high grounds form 

 extensive tracts of moor-land. In the lower districts of country over which it 

 extends, the soil generally rests not on the rocks themselves, but on superficial 

 accumulations of transported materials, which are often of such a kind as to 

 form a soil either productive in itself or capable of being rendered so by skilful 

 cultivation. 



16°. Mountain ) ^^.. f. In this formation, as its name implies, 



Lime-stone. S lime-stone is the predominating rock. 



It is generally hard, blue, and more or 



