302 SOILS AND SOIL PROCESSES. 20. 



fcarcely another spring belonging to it, not 

 fcarcely a perch of springy soil upon its 

 lurfacf. 



The limeftone andredftone land lies alien 

 ROCK above the level of this fpring. The 

 pebbly loam which lies below it is equally 

 fortunate in a feam of gravel, which, tho* 

 it lie fome feet beneath the furface, renders 

 it fufficiently dry to be worked at all feafons, 

 and to carry ftock in winter with impunity. 



Under thefe circumftances underdrain- 

 iNG is rendered ufclefs; and no inftance of 

 it occurs in this neighbourhood, except in 

 the improved peatbog, which was mentioned 

 under the article Planting, and which lies 

 in the immediate vicinity of the fource of 

 the Cofta •, by whofe waters, before the 

 channel of the river was made, that bed of 

 moor had been formed. The wetter parts of 

 the area received confiderable improvement 

 from underdraining. 



But altho'the fubllrudture of the margin 

 is fuch Lis to preclude the ufe of under- 

 draining, that of i\\Q f-joells which rife in the 

 BOTTOM OF THE Vale rcndcrs this operation 

 frequently ncccilary •, and in fome few in- 

 ftances it has been pradtifcd with great 

 fucccfs. 



