springs usually break out pretty high on the sides 

 of elevated grounds and mountains ; but no person 

 acquainted with chalky districts will allow that they 

 ever saw springs in such a soil, but only in valleys 

 and bottoms, since the waters of so pervious a 

 stratum as chalk all lie on one dead level, as well- 

 diggers have assured me again and again. 



Now we have many such little round ponds in 

 this district ; and one in particular on our sheep- 

 down, three hundred feet above my house; which, 

 though never above three feet deep in the middle, 

 and not more than thirty feet in diameter, and con- 

 taining perhaps not more than two or three hundred 

 hogsheads of water, yet never is it known to fail, 

 though it affords drink for three hundred or four 

 hundred sheep, and for at least twenty head of large 

 cattle beside. This pond, it is true, is overhung 

 with two moderate-sized beeches, that doubtless at 

 times afford it much suppl}^ ; but then we have 

 others as small, that, without the aid of trees, and in 

 spite of evaporation from sun and wind, and per- 

 petual consumption by cattle, yet constantly main- 

 tain a moderate share of water, without overflowing 

 in the wettest seasons, as they would do if supplied 

 by springs. By my journal of May, 1775, it appears 

 that " the small and even considerable ponds in the 

 vales are now dried up, while the small ponds on the 

 very tops of hills are but little affected." Can this 

 difference be accounted for from evaporation alone, 



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