400 



APPENDIX. 



Fig. I. Represents a piece of ground wet by surface 

 water, owing to tlie retentive subsoil and want of de- 

 cli\dty, to remedy which the following operations will be 

 necessary. 



Fig. I. 



Cut a drain, as AB, along the lowest level of the field, 

 of such dimensions as to contain the quantity of water, 

 which may be easily judged of by the extent and natui'e 

 of the grounds. This is called the leading or main drain ; 

 and where the ground is unequal, forming hollows, it will 

 be necessary to have side drains leading into the main 

 drain : these will require to be half the size of the main 

 drain or leader, and are represented by C and D. When 

 the ground rises into brows or eminences, such as at EFG, 

 the tabling or small conductors must be carried in the 

 direction of the declivity, either into the leader or side 

 drains. Nos. 1, 2, 3, 4 represent dry porous gi'ound, 



