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side of the field, at a distance of the breadth of a furrow from the fence, and 

 empties by one outlet at the lowest part. 



It is of great importance to have as few outlets as possible. 



If stones are actually on the ground, it may be found cheaper to nse their 

 for filling the drains, but upon the whole, tiles are found the most economical. 

 They are lighter than stones, and therefore require less carriage. The water 

 also runs more freely in them. One to two-inch pipes are generally used, and 

 it is always best to lay them with collars. It is unnecessary and wasteful to 

 have the same sized tile at the upper part as at the lower part, of a drain. 

 Mains vary in diameter, according to the amount of water. From four to six- 

 inch pipes are generally sufficient. 



The average expense, in Great Britain, of draining an acre, may be stated 

 at about <£5 10s. In this country it would cost considerably more. Until the 

 expense is reduced, the system is therefore not likely to come into very general 

 nse, but for small pieces of ground, and particularly gardens, it ought even now to 

 be applied. In garden ground, no doubt, the pipes are apt to -get choked with 

 roots, but the damage soon shows itself, and the pipe must simply be lifted 

 and cleaned, and then relaid. 



Although there is much excellent natural drainage in this country, yet 

 many districts would be immediately improved by thorough drainage. 



Without going far, I might mention Karori, Porirua, and parts of the 

 Hntt. 



RECAPITULATION. 



1. Drains should follow the steepest slope. 



2. They should, if possible, have a minimum depth of four feet 

 'perpendicular. 



3. The main should have a depth of six inches more than the small 

 drains. 



4. The chief main should be cut along the lowest side of the field, parallel 

 to the fence, and should empty by one outlet only. 



5. The interval between the drains should vary from twelve to thirty-six 

 feet, according to the stiffness, or openness of the soil and subsoil. 



6. It is a waste of material to put the same size of pipe at the upper as at 

 the lower part of a drain. 



7. Pipe tiles are far more permanent, and in the long run cheaper, for 

 drainage, than any other material. They ought to have collars. The run of 

 water is more free in them than in any other kind of drain. 



A little consideration will show what a difference it will make in the fertility 

 of land, if the water, which now lies, during the winter months, either on the 

 surface, or close below it, and in a stagnant state, is kept flowing at a depth of 

 four feet below. In the one case the roots of plants are perished by the water, 

 in the other they are nourished, and the rain water also, percolating freely, 

 assists decomposition, and removes noxious matters. 



Wet land in its natural state is unfit to receive manure, which is wasted 

 if put upon it. When drained it is ready to take advantage of any appli- 

 cation of fertilizing material. 



In its natural state the ground is hard to work. It is sodden with water 

 in winter, and forms hard clods in dry weather. When drained, it is easily 

 worked at all seasons, and breaks up into fine mould. 



The returns from drained land are proportionately great. I can speak 

 from experience when I say that nothing pays better in Great Britain than 

 judicious drainage of land. On the other hand, a large landed proprietor 

 in the Midland Counties informed me that he had thrown away =£24,000 

 upon drainage which would have to be entirely done over again. He had been 

 persuaded that a two-foot drain would be ample, and found that the depth 



