THE YOUNG FARMER'S MANUAL. 289 



drain is in order to be most effectual above the wet ground be 

 tween the wet ground and the dry. The slope of the field must 

 determine how far above the wet ground the drain should be 

 made. If the surface of the ground slope about six inches in a 

 rod, the drain should be made not less than forty or fifty feet 

 above the wet ground. The idea is, to have the diagonal drain 

 far enough above the wet ground to cut off the veins of water 

 which render the ground wet, so that they will be near the bottom 

 of the drain. 



398. There are veins of water all through the earth in most 

 localities ; and if a drain intersects any of these veins, the water 

 flowing from them will find its way to the bottom of the drain, 

 even if the drain should be filled with clay, well rammed in. But 

 if the drain is not deep enough to reach a vein, the water in it 

 will flow on, and come out at the surface, as it always has done, 

 and the drain will be of little benefit. Sloping fields, which lie 

 below large bodies of standing wood, or below large tracts of 

 swamps or wet land, are very liable to be so wet as to need 

 thorough draining ; whereas, if the woods above them were re 

 moved, or the wet ground alluded to were well drained, those 

 sloping fields would be sufficiently dry, in some instances, without 

 drains. In such instances the water from above may, many times, 

 be cut off by running a deep drain along the upper side of the 

 field, to receive the water as it finds its way from the up land, and 

 spreads over the fields below. One of the fields on my present 

 farm slopes to the west about six inches per rod. About one- 

 fourth of a mile above it was a tract of wet, swampy land, which 

 was supposed to be the source of the numerous veins of water 

 which out-cropped in this sloping field. The sloping field has 

 been drained ; and before the swamp above was drained, the 

 drains in that sloping field emitted an abundance of good water, 

 as long as there was water in the swamp. But now that the 

 swamp has been drained, the water in those drains in the sloping 

 field fails early in the season, showing very conclusively that the 

 source of the water has failed. 



399. Sometimes mill-races or canals are cut along hills, and the 



