On the Agricidtwal Geoloyy of England and Wales. 479 



tions, is, that wherever there are rivers in it^ the slopes hans^ing 

 to the vales through which they run, and the bottoms themselves, 

 are of a superior quality, composed in general of rich friable 

 loam, and that this holds good of many inconsiderable streams 

 which fall into the larger rivers. The same remark, with modi- 

 fications arising out of the different structure of other districts, is 

 repeated, as will be seen hereafter, by several of the writers who 

 describe other counties. 



The statement is nearly identical with that in the paper on the 

 Geology of Norfolk, in the seventh volume of the Society's 

 Journal, which asserts the dependence of the variations of soil on 

 contours. Let us now test the truth of the opposite doctrine, 

 which refers these variations to variations in the compo.sition of the 

 formations of our geological maps, by tracing them through the 

 maps and descriptions of the agricultural writers. We will com- 

 mence with the chalk, one of the most important of these forma- 

 tions. The whole eastern side of England, from the confines of 

 Devonshire and Dorsetshire on the south, to the north-west angle 

 of Norfolk, may be regarded as a great sheet of chalk, covered 

 more or less by tertiary strata of all ages, and broken through 

 and denuded, along an east and west line of disturbance, in the 

 Weald of Kent and the Vale of Wardour. A smaller area re- 

 appears north of the Wash, on the eastern side of Lincolnshire 

 and Yorkshire, partially covered by the erratic tertiaries. It will^ 

 therefore, be a convenient arrangement to notice the variations of 

 soil on the districts of the older tertiaries in tracing the soils 

 of the area assigned to the chalk on geological maps. 



By the prevalent hypothesis, the soils of that area should be 

 white and calcareous. So much, however, are such soils the 

 exception rather than the rule, that from Yorkshire to Cambridge- 

 shire they are scarcely mentioned ; and through the remainder 

 of the chalk range they are described as confined to certain 

 elevations and forms of surface, that is to say, they are dependent 

 on contours. 



The Wolds of Yorkshire are divided into the Northern and 

 Southern Wolds, their height above the sea being 812 feet in the 

 north, and 500 feet at the southern termination of the southern 

 Wolds. LTpon the elevated plains of the northern Wolds, we are 

 told by the agricultural writers, that there is a uniform covering 

 of diluvial matter, 18 to 24 inches thick, consisting of a deep- 

 coloured, loamy soil, with an occasional mixture of clay.* Pro- 

 fessor Phillips states, in his ' Geology of Yorkshire,' that the 

 boulder clay or till of Llolderness runs up some of the valleys of 

 the Wolds. His coast-sections show a considerable thickness of 



* Legardj Journ. Roy. Agri. Soc, vol. ix. p. 86 ; Strickland, Rep. Bd. of Agri. 



