DETAILS OF SUB-IRRIGATING. 7! 



come above the top of the bench, in order to admit of 

 inserting the hose in watering. When the tiles are laid 

 crosswise the benches, several may be watered at once by 

 means of a piece of gas pipe with holes bored at suit- 

 able distances. When the tiles are laid, they are simply 

 placed end to end, and no cement is needed, although it 

 is sometimes used to prevent the tiles becoming dis- 

 placed in filling the benches with soil. 



"Gas pipe, with holes bored at intervals, has been 

 used with success ; also a pipe, called 'structural iron 

 pipe.' This differs from ordinary iron pipe in having a 

 slot along one side. Where the slot is nearly closed, so 

 as to not allow the water to flow too freely, this pipe 

 answers very well, but a^-inch drain tiles are cheaper 

 than anything else, and are perfectly satisfactory. These 

 tiles are, of course, removed and put in place again each 

 time the soil in the benches is renewed. Another thing 

 in favor of 2> or 3-inch tiles, is that the capacity is suffi- 

 cient, so that it may be filled quickly and the operator 

 may go on to another tile, allowing the water to soak 

 out into the soil, knowing that enough has been given to 

 last several days ; but if iron pipes are used, the size 

 must be small because of the cost, and the watering must 

 be more frequent in consequence." 



Rane speaks as follows (Bull. 33, W. Virginia Station) 

 of the equipment of the sub-irrigation bench: "The ques- 

 tion of economy, when considering the advisability of using 

 sub-irrigated beds, is justly a worthy and important one. 

 There must be a water-tight bed to retain all the water in 

 the soil, the construction of which is necessarily more 

 expensive than in the ordinary method of making beds, 

 provided boards are used. The pipe or tiles are likewise 

 an extra expense. Now, will this expenditure be realized 

 from the advantages gained? The cost of raw material, 

 for example, in two houses, each 50 ft. long and 20 ft. 

 wide, one being arranged for surface and the other for 

 under-surface watering, would be about as follows: 



