10 ELEMENTS OF STLVICULTUEE. 



purposes. The eastern is the most favourable 

 aspect for forest vegetation. 



On these two aspects, especially on the northern, 

 the vegetation being tardy escapes spring frosts, but 

 the shoots of the year which are not sufficiently 

 lignified when autumn comes on, are apt to suffer 

 from early frosts. 



On a southern aspect the sun shines almost all 

 day long, the temperature is high, and the light 

 intense in its action ; the winds are strong, and are 

 often accompanied by storms and torrents of rain, 

 which thoroughly soak the ground, and wash the 

 soil down the slopes. Under these circumstances 

 the topsoil, generally superficial, dries up rapidly ; 

 the trees are slow in growth, misshapen in form ; on 

 the . other hand the timber is thoroughly lignified, 

 and though it is unsuited for carpenters' work, it is 

 in great demand for building purposes when its 

 shape allows of its being so used. 



On a western aspect the sun shines obliquely, but 

 during the hottest hours of the day ; the temperature 

 is high, and the light fairly strong; the soil retains 

 moisture with difficulty. The winds have the same 

 character as on a southern aspect, and here, too, we 

 find timber of slow growth, ill-shapen form, possess- 

 ing the same good qualities and the same defects. 



On these two aspects, the vegetation is early, and 

 the young shoots of the season often fall victims to 

 spring frosts. 



Mountainous countries, especially deep moist 

 valleys, are always exposed to the danger of frost, 

 because the atmosphere is laden with watery vapour, 



