35G On the MaJcing and Using Tiles for Under- Draining. 



Yet both these drains require an equal number of tiles. The 

 error of shallow draining arises from an anxiety to see no water 

 stand on the surface : but the object of draining is not to take off 

 the water as fast as it comes down, but so fast as to prevent injury 

 to vegetation. It must, however, be confessed that shallow drain- 

 ing often arises from inefficient ditches, even where the fall is 

 ample. If there is any apprehension of the water not going off in 

 time to prevent mischief, the farmer should put a few loose stones 

 over the tile before filling in, and fill in with the loose more 

 friable top soil. 



14. Inexperienced drainers with tile often deem the flat or bot- 

 tom tile superfluous ; but there is no security for permanence but 

 In the flat continuous pavement, with an uniform and not too 

 quick descent : it must lie so firm on the soil that the drainer 

 may walk backwards on it from the lower part of the drain 

 upwards, carefully placing the arched tiles on the bottom tiles, 

 so as the jointings of each come to the middle of the others ; and 

 seeing that the water flows away as he goes on. Accuracy, and 

 even nicety, in laying tiles is essential to their success. 



London, July, 1839. 



