7. YORKSHIRE. 169 



been made, the ufe they have been liable to, 

 and to the fteepnefs of their fides, — the ftones 

 are entirely difplaced or trodden into the 

 clay ; which is by this means oppofed to the 

 feet of cattle, and to the open attack of 

 drought and worms. For a while the clay, 

 even thus expofed, prcferves its rctentive- 

 nefs ; but in time it is defiroyed, and the moft 

 valuable part of the pond entirely loft. 



This eife<ft is io probable, fo evident to be 

 forefeen, that, on firft refieiTtion, it feems afto- 

 niftiine fo unfuitable a coverins; Ihould be 

 univerfally adopted. A beafl when it goes 

 into a drinking pic ncceflarily throws the 

 chief part of its weight upon its fore feet ; 

 which, in the aft of drinking moll efpecially, 

 are placed as for the intention of forcing 

 whatever they ftand on down the Hope to- 

 ward the bottom of the pit. Upon loofe ftones 

 laid on a fteep furface, cattle cannot make a 

 flep, or move a foot, without producing this 

 effeft in a greater or lefs degree ; and by re- 

 petition and length of time, the entire coac 

 (except fome few which happen to be trod- 

 den into the clay) muft, in the nature of 

 fhingSj be forced into the center. 



But 



