228 



THE NORMAL AGE CLASSES. 



Their prevailing direction must be ascertained, and cuttings 

 must proceed against it. Assuming that the strong winds 

 generally blow from the west, the youngest age class should, 

 at the commencement, be situated at that side, and the oldest 

 on the east, so that the cuttings proceed gradually from east 

 to west. (See diagram, fig. 48.) 



_r 



o 6 xo 16 3.0 



Fig. 48. 



In determining the prevailing wind direction it must not 

 be overlooked, that it is frequently changed in hilly and 

 mountainous tracts according to the direction of the valleys 

 and hill ranges. 



Dry winds may frequently blow from a direction differing 

 from that of strong winds ; in that case the forester must 

 decide which is the more important consideration of the two, 

 and determine the cutting direction accordingly. Frequently 

 the seeds of trees fall under the effect of a dry wind, so that 

 the cleared areas, which are to be naturally regenerated, must 

 be situated to the leeward of the seed-bearing trees. 



Large clearings in one place are generally objectionable 

 because the soil is liable to dry up, and damage by frost is 



