Chap. XVI. 0/ Ridges. 243 



and carries it away ; then they cover the Trenches 

 with Mould, and plow over them as in dry level 

 Ground. 



This Method has been found effectual for a time, 

 but not of long Continuance ; for the Trenches are 

 apt to be ftopp'd up, and then the Springs break 

 out again as before : Befides, this is a very chargeable 

 Work, and in many Places the Expence of it may 

 almoft equal the Purchafe of the Land. 



Therefore 'tis a better Method to plow the Ridges 

 crofs the Hill almoft horizontally, that their parting 

 Furrows, lying open, may each ferve as a Drain to the 

 Ridge next below it •, for when the Plough has made 

 the Bottom of thefe horizontal Furrows a few Inches 

 deeper than the Surface of the Clay, the Water will 

 run to their Ends very fecurely, without nfing into 

 the Mould, provided no Part of the Furrows be 

 lower than their Ends. 



Thefe parting Furrows, and their Ridges, mud be 

 made more or lefs oblique, according to the Form 

 and Declivity of the Hill ; but the more horizontal 

 they are, the fooner the Rain-water will run off the 

 Lands ; for in that Cafe it will run to the Furrows, 

 and reach them at right Angles, which it will not do 

 when the Ridges (or Lands) are oblique; and there- 

 fore the Water's Courfe crofs the Lands will be 

 longer (a). Every one of thefe horizontal Trenches 



receives 



fa) The natural Courfe of Water being downwards, it would 

 always run by the neareit Way to the Bottom of the Hill, if no- 

 thing ftopt it ; but the Water runs from an Hill in Two Manners ; 

 Wf'z. Upon the Surface of the Staple, and upon the Surface of 

 the Clay that is under the Staple ; that which runs under keeps 

 its ftrait Courfe from the Top to the Bottom of an Hill, under a 

 Ridge that is made exactly with the Defcent of the Kill, except 

 that Part of the Water that rifes up into the Mould, and a very 

 little that foaks into the Furrows , for when the Furrows are not 

 made exadly with the Defcent, the more oblique they are to the 

 Deicent, the longer will be the Water's Courfe under the Ridges ; 

 and the ihorter, as they are nearer being at Right Angles to the 



R 2 . Defcent. 



