106 



DIRECTION OF THE DRAINS. 



verse or oblique to the slope, it will often happen 

 that, no matter how skilfully planned, they will 

 not reach these partings at all, as at («). In this 

 case, the flow will continue in its accustomed chan- 

 nel, and discharge its waters at (b). But again, 



even though it does reach these partings, as at (c), 

 a considerable portion of water will escape from the 

 drain itself, and flow to the lower level of its old 

 point of discharge at (d). Whereas, a drain cut in 

 the line of the slope, as from (d) to (<?), intersects 

 all these partings, which furnishes an outlet to them 

 at a lower level." 



Mr. French in his " Land Drainage," in remark- 

 ing on this description by Mr. Girdwood, says : 

 " The line of the greatest fall is. the only one in 

 which a drain is relatively lower than the land on 

 either side of it. Whether we regard the surplus 

 water as having recently fallen upon the field, and 

 as being stopped near its surface by an impervious 

 stratum, or as brought down on these strata from 

 above, we have it to be disjoosed of, as it rests 



