DRAINING. 33 



In all these cases, thorough, drainage will abundantly pay. 



As we have before hinted, nearly all land will be improved 

 by drainage ; for the expense is a permanent investment, a 

 brush drain will last ten to fifteen years, a well laid stone drain 

 twenty to forty years, and there is no reason why a perfect tile 

 drain may not last one hundred years. In all this time the 

 crops are improved both in quantity and quality, 



A distinction can be made in view of crops to be raised, as 

 land that is too wet for root or grain crops, may do admirably 

 for grass, and it is often well to keep such lands permanently 



I in grass, maintaining their fertilit}'- by top dressing or by occa- 

 sional plowing and re-seeding in the fall. The indications of 

 too much moisture are, in grass, the growth of rushes and 

 weeds ; if it be in grain, there "will be frequent spots of sparse, 

 low, and sickly looking stalks. Root crops, in too wet soils, 

 instead of growing straight down plump and even, divide into 

 numerous small fibres just below the surface. Our corn fields 

 are yellow and sickly, and our cribs filled with nubbins fiom 

 the effects of too much water in the soil. 



Drains should be laid as far as practicable, directly down Ae 

 slopes. A fall of three inches in one hundred feet, is all that is 

 absolutely necessary, and this can be secured on almost any 

 field, however level it may seem to the eye. The best means 

 of determining the slope is with the span. Fig. 6. This may be 

 made of lath or inch boards, and should be sixteen and one half 

 feet wide at the base. When set upon a perfectly level floor, 

 and the plumb line applied at the top the line will croas the bar 

 in the centre, put a block just one inch thick under one foot 

 and mark the bar where the line now crosses it, this denotes a 

 fall of one inch to the rod. This operation repeated, if done 

 with care, will give a sufficiently accurate measure for the 

 whole work of laying out and constructing the drains. 



