Field Drainage. 43 



out hard and firm ; and the ground, owing to the effect of the 

 drainage, will never again be so charged with water as to 

 make them liable to be stopped up ; and even should the 

 ground, from any exceptional cause, be drowned, after the 

 soil in the trenches had once become settled and consolidated, 

 there would be no danger of the water washing it into the 

 pipes, as it would find its way to them through the regular 

 crevices or canals. 



Depth. — With regard to the depth at which pipe-drains 

 should be laid, this must depend to a great extent on the 

 outfalL There may be special circumstances where drains 

 may be advantageously laid at great depths, and by 

 neglecting to descend a few inches in certain soils, many of 

 the benefits of drainage may be lost. Again, where springs 

 occur it is often necessary to lay the drains at considerable 

 depths, and to resort to special means of getting rid of the 

 water, as by boring down through an impervious soil to the 

 porous stratum below. But these are cases which seldom 

 occur in low land drainage. There are many cases, however, 

 in fens and marsh land, where the state of the outfall ditches 

 will not allow of a greater depth than 2 feet. The pipes 

 should never be laid so low that their ends are buried in the 

 water in the ditches into which they empty; such a practice 

 is simply laying pipes for the purpose of soddening the 

 land with water instead of draining it. It completely stops 

 the whole circulation of air, and arrests all the benefits to 

 be derived from a properly laid drain. A drain laid 2 feet 

 deep, and free at the end, is far more effective than one laid 

 3 feet with the outfall constantly under water. 



The outfall of the drains where they empty into the 

 ditches should be constantly inspected to see that they are 

 free and not stopped with weeds and earth. The ditches 

 ought to be regularly scoured out and cleaned once at least 

 every season. It is a good plan to lay the last tile of the 

 main drain on a flat paving tile or brick, and to place a small 



