17^ DP.INKING PO OLS. 7* 



ralfed ; and fome few unfuccefsful attempts 

 have btren made : the channel was in one in- 

 ftance (that of Newton) extended a confider- 

 able way before the impracticability of comi- 

 pleting it at a moderate expcnce was difco- 

 vered ; a piece of mifcondudt which nothing 

 but a want of accuracy in the ufe of the level 

 can lead to *. 



'Ihc firji coji of Kirby-rill was not altoge- 

 ther one hundred pounds. The d'ljiance about 

 ten miles : watering (befides the town of 

 Kirby) two villages, and aline of cultivated 

 waterlefs upland country about four miles in 

 kngth. 



Befides 



■" The milcarnage in this cafe was net owing to a 

 war.t of elevation in the for.rcc, but to a depreffion of 

 the channel at the foot of the fteep ; the head of the 

 valley (if fuch it may be called) bting lower than the 

 top of tl e prc/i ice at the given point. This flicw3 

 the ncceility of tracing the cnire channel with fufTicient 

 accuracy before any other expence be incurred. 



In the cafe of Kirby the channel is raifed fome feet 

 by a bridgc-iikc mound of earth thrown acrofa the 

 crown f f tl e vaiky. 



The tan'c mound fcrves the purpofc of conducing 

 another rill acrofs the fame difficult [ afs ; from whence 

 the Kirby-rill takes an eaihvanU the rill of IVellbuni 

 (applied principaUy to the watering of paflure grounds) 

 ? uellward direction. 



