84 THE PRINCIPLES OF 



pursuits with the same ease and pleasure with which they can 

 be carried on in more rural districts. In the third place, the 

 air becomes polluted. It is melancholy to read Mr. Clare 

 Sewell Read's report on farming in South Wales. He speaks 

 of blighted trees and blighted crops, owing to the gases 

 vomited forth from a thousand chimneys ; and cases are not 

 uncommon of damages having been claimed and recovered 

 in these districts for injury caused to vegetation. All of these 

 things are against agriculture ; but, in addition to this dis- 

 advantage, the soil is usually poor. Nature, which has been 

 so lavish in underground wealth, seems to have held her hand 

 with reference to the surface fertility of these districts. They 

 are often composed of cold soils, and taking into consideration 

 all their features, they are not favourable for agricultural 

 purposes. 



I have yet to mention the mountain limestone in associ- 

 ation with the coal-fields. Our great national wealth is in 

 great measure due to the proximity of limestone to coal. 



The mountain limestone almost invariably surrounds the 

 coal-fields. Whether we take the Bristol, the Northumberland, 

 the Yorkshire, the Durham, or the Welsh coal-fields, we find 

 that the mountain limestone is never far distant. 



The mountain limestone gives soils of poor thin character. 

 They, together with the rocks of the millstone grit and 

 Yoredale rocks, unite the Yorkshire and the Lancashire coal- 

 fields, giving a somewhat barren succession of moorlands 

 intersected by fertile dales; and, in fact, from the Peak 

 district of Derbyshire, where the mountain limestone com- 

 mences, through the dales of West Yorkshire and East 

 Lancashire, right up to the moorlands which surround Stan- 

 hope, Kilhope, and Walhope, and the Weardale district of 

 South Durham, and down into Northumberland, where we 

 find ourselves upon the moorlands, extending to Allen Heads 

 and Cumberland, pastoral pursuits prevail and agriculture 



