SOIL, MANURES, SITUATION, AND ENCLOSURES. 51 



soils of naturally moderate fertility. Many parts of the 

 Western States possess a soil quite rich enough, provided 

 good cultivation is given. A well-drained subsoil is of course 

 all-important, for all manure is nearly lost on land kept soaked 

 with water. Even old bearing trees have been much im- 

 proved by laying tile two and a half or three feet below the 

 surface, midway between the rows (Fig. 79). The young 

 forming-roots, being the most remote from the tree, receive 

 the greatest benefit from drains thus placed, and the tile is 

 less liable to be thrown out of position by large roots or filled 

 by smaller ones. 



SITUATION. 



After a suitable soil is obtained, hardy trees, such as the 

 apple, will usually succeed in almost any situation. But with 

 tender fruits, as the peach and apricot, the case is very differ- 

 ent. In many localities in the Northern States, they are soon 

 destroyed by the severity of winters, and their cultivation is 

 accordingly not attempted. In others, crops are not yielded 

 oftener than once in two years. But some situations are so 

 favorable, that a failure scarcely ever occurs. In planting out 

 tender fruits, it is consequently desirable to know what places 

 will prove the best. Even the apple, in regions where the 

 winters are rigorous, is sometimes destroyed by frost, and in 

 very unfavorable places rarely escapes. 



It is familiar to many cultivators, that warm, low valleys 

 are more subject to night-frosts than more elevated localities. 

 Objects at the surface of the earth are chilled by the radiation 

 of heat to the cold and clear sky above, and they cool by con- 

 tact the surrounding air, which thus, becoming heavier, rolls 

 down the sides of declivities and settles like the waters of a 

 lake, in the lowest troughs. This coldness is further increased 

 by the stillness of those sheltered places favoring the more 

 rapid cooling, by radiation of the exposed surfaces ; while on 

 hills the equilibrium is partially restored by currents of wind. 

 Superadded to these causes, vegetation in low, rich, and shel- 

 tered places is more luxuriant, and wood less ripened, and 

 hence particularly liable to injury from frost. The mucky 

 soil of valleys radiates heat rapidly from its surface. The 



