HOW DOES THE WATER GET IN ? 37 



Now he does — what? The most important of all things, 

 after great care in laying the tile, is to pack them securely. 

 He puts directly upon the tile the finest, most compact, most 

 clayey soil that he can find, without a particle of vegetable mat- 

 ter, — no grass, no straw, no shavings, no' leaves, no anything, 

 except this hard, clayey soil, which is put on to the depth of 

 seven or eight inches, and then gently beaten, to fix it in its 

 place, and make a perfect matrix round the tile, holding it per- 

 fectly tight. I believe that one operation has more to do with 

 the permanence of a well-laid tile drain than any other one 

 part of the work. It is very natural to think that if we put a 

 pipe into the ground, we must put some porous material over 

 it, to enable the water to pass through to the tile ; so we throw 

 over it brush, or leaves, or something of that kind. That is 

 not the way the water gets into the drain at all ; it comes up 

 from below ; and in putting this porous material over the tile, 

 the chief end we accomplish is to put there a mass of organic 

 matter, that is sure to decompose and form a fine mould, which 

 will be carried, by the little water which comes trickling from 

 above, into the tiles, and perhaps choke them up, by accumu- 

 lating at one point or another. 



I have said that the water gets into the tiles from below. 

 This idea may possibly be new to some of you, but it is one 

 which is very well established. In a dry season, when it has 

 not rained for several weeks, the soil is dry, not only down to 

 the level of the drain, but for a considerable distance below it. 

 The water table has settled down so that the water level in the 

 wells is perhaps ten feet below the surface. There comes a 

 heavy rain. Now, when the water falls upon the ground, it has 

 no instinct to teach it that there is a drain in a certain direction 

 into which it may get and be carried away ; it will simply follow 

 the law of gravitation, and descend into the soil until it strikes 

 the water table, and if the rain continues, the water table rises 

 nearer and nearer the surface, until finally it rises to the height 

 of the bottom of the tiles, and then, as if it had risen to the 

 top of a drain, where it would run over, it runs into the drains 

 and escapes. In my opinion, the idea that water ever, for any 

 considerable distance, travels laterally to find a drain is quite 

 a fallacious one. It is a natural one, but it is a fallacy. It is 

 one that will not hold water. 



