10 Southe7~n and WesteiTi Aspects. 



42. A southern aspect receives both the heat and light with great- 

 est intensity, and is more liable to winds and storms, and the soil to 

 erosion from rains, than any other. The trees, on the whole, are of 

 slower growth, owing to deficient moisture, and are less regular in 

 form, but the wood is firm, heavy, and strong, well adapted to all 

 uses where these qualities are required. Seeding can seldom be se- 

 cured on a steep southern aspect in a warm, dry climate, and trees 

 must be set from nurseries and attended with greater care. The 

 south side of a mountain is much more likely to be bare than any 

 other, every thing else being equal. 



43. A western aspect receives the sun obliquely, but in the warm- 

 est part of the day, and in our Western States, vegetation is most 

 exposed on these slopes to drying winds. The soil is apt to become 

 dry, and timber is therefore of slower growth and less regular in 

 form, but in the main good. 



44. These differences from aspect are more noticeable in elevated 

 regions than in low grounds, and they depend in degree more or less 

 upon the nature of the soil, and local climatic influences that may 

 determine the direction of the surface winds, or otherwise aifect the 

 location. 



45. The degree of inclination has also a notable influence upon 

 vegetation, and on the action of rains upon the surface. If less 

 than one in six, the conditions are generally good. From this to 

 one in three, agricultural cultivation becomes difiicult, and the sur- 

 face is liable to wash ; still, the roots of trees can find a hold; and, 

 if they can get deep into the soil, forests will prosper. At still 

 greater angles, cultivation becomes difficult without terracing, and 

 the_dangers from erosion become greater. Upon such extreme 

 slopes, pasturage is apt to cause great injuries by destroying the 

 herbage and allowing the soil to wash into the valleys. The true 

 policy should be to keep them covered with woodlands, if possible, 

 and to clear by selection, never exposing the whole surface at once. 



CHAPTER III. 



OP CLIMATE AND METEOEOLOGICAL INFLUENCES. 



46. We understand by climate, the atmospheric conditions of a 

 given region, resulting from its latitude, elevation, temperature, 



