OPERATIONS OF DRAINING. Ill 



at intervals along the side of the drain, and filled with 

 stones in the manner shown in fig. 13. 



" In all cases of under-draining, the drains should be 

 made of sufficient dimensions. They should not be less 

 than 4 feet deep, even when the pervious stratum lies a 

 less depth ; and the reason is, that they may be more 

 permanent, and better defended from injury, from mud 

 and sand carried down by surface-water. It is not neces- 

 sary that they be made deeper than 4 feet when that is 

 found to be sufficient ; but they must be carried, if neces- 

 sary, to the depth of 6 feet, or sometimes of 7 feet, 

 though the expense and difficulty of executing the work 

 increase, in a great proportion, as the dimensions of the 

 drain increase. 



" The importance, in this species of draining, of pro- 

 ceeding upon principles in laying out the lines of drains, 

 instead of acting at random, as so many do, cannot be too 

 strongly impressed upon the attention of the drainer. 

 Every drain, however rudely devised, and imperfectly 

 executed, may do some good. But one drain well laid 

 out, and of the required dimensions, may perform a pur- 

 pose which no multiplication of minor and insufficient 

 drains can effect. These may lessen the efiects of wet- 

 ness, but the other is designed to remove the causes of 

 it ; and the more perfect practice will usually be found, 

 in the end, to be the most economical as well as the most 

 efficient. 



" The drains of the larger class described, it will be 

 seen, are intended solely for the removal of water which 

 is contained in reservoirs and channels below the surface. 

 They do not supersede the necessity of carrying away 

 water which is at or near the surface. From this latter 

 cause, an equal or greater injury may arise, and must be 

 met by a corresponding remedy." — Professor Low^s Ele- 

 ments of Agriculture. 



Under- drains, for the want of stones or tiles, are some- 

 times constructed of other materials, as boards, plank, 

 brush, straw, turf, &c. We have tried them all. They 

 serve a temporary purpose, and may be resorted to as 

 matters of necessity. But we would not advise their use 



