40 TILE DRAINAGE 



is known as "bonlder clay." It is a very retentive soii 

 and when dry becomes hard and cloddy. There is usually 

 sufficient fall in these lands to admit of good drainage ; the 

 drains, however, should be placed shallow and near to- 

 gether. 



The second class of lands comprises those that lie too 

 high to be overflowed and are usually more or less rolling. 

 On these the boulder clay, instead of coming to the surface 

 as in the preceding class, is covered with a mantle of brown- 

 ish loam ten to twenty inches in thickness. These lands, 

 where not too stony or in forest, are ordinarily cultivated. 

 The clay coming so near the surface, however, causes them 

 to dry out very slowly in the spring and makes the planting 

 season that much later. There will ordinarily be no 

 trouble in securing plenty of fall and good outlets on these 

 lands, and the drains may be placed at a medium depth and 

 about fifty feet apart. 



In the third class we have those lands that are quite level 

 and flat and are so wet during the greater part of the year 

 that only wild grasses can be grown on them. The soil is 

 dark colored and frequently quite black, owing to the large 

 amount of organic matter in it. It is usually lighter in 

 texture than the so-called meadow lands, being considerably 

 more sandy and porous. Its origin is also different, having 

 been formed from the gradual accumulation of organic 

 matter and the material carried by streams. The fall on 

 these lands is likely to be slight, but the drains may be 

 placed fairly deep and far apart. When well drained they 

 will be found in the course of several years to be productive; 

 for both cultivated crops and grasses. 



The fourth class of lands are found only in a limited 

 extent in New Hampshire, being confined to the coast sec- 

 tion. They are more or less sandy and have been formed 

 in a way similar to those in the preceding class, except that 

 in this case the material has been deposited by Avaves and 

 tides. The natural vegetation of these lands is largely 

 swale, bunch and other inferior varieties of grasses. Their 



