RELIEF DRAINS. Ill 



and that any system which does not provide a direct 

 release for water, which would otherwise collect in 



and be drawn toward these spots, is imperfect and 

 unsatisfactory. It is found to be much more safe 

 to depend on relief drains, than on cutting them 

 sufficiently deep through the banks at (««), to gain 

 a fall at a regular inclination. 



" Still, in spite of experience, we often observe a 

 disregard of these facts, even in works which are 

 otherwise well executed to a depth of four feet, but 

 fettered by methodical rules; and I feel compelled 

 to remark that it has often occurred to me, when I 

 have observed with what diligent examination the 

 rules of depth and distance have been tested, that 

 if more attention had been paid to the source of 

 injury, and to the mode of securing a permanent 

 and effective discharge of the injurious water, much 

 greater service would be done." 



The distances between the drains should be mod- 

 ified also by the amount of annual fall of rain in 

 the district. In some parts of our country the 

 number of inches of yearly fall is double that in 

 others. The spaces between the drains should also 



