Sub-Irrigation 



the top of the soil generally from a hose, and in considerable quantity, passes 

 downward and compacts the soil, so that upon a surface-watered bench that 

 has been some months in operation the soil frequently becomes almost as 

 hard as a brick when dried. 



There are a number of systems of constructing- sub-irrigation benches. 



Sub-Irrigation Bench 



Showing manner oi laying Terra Cotta foundation and protecting 

 supporting columns 



One of them is described in Chapter X\'I., which deals with bench con- 

 struction. Several thousand running feet of these benches have been in 

 operation at the Cottage Gardens for several years past, and have, as a rule, 

 produced better average crops of flowers, both as to quantity and quality, 

 than have been obtained upon the surface-watered bench with the same varie- 



175 



