70 



percolations of the snperineumbent border. "We lay 

 a layer of thick turves on this, merely sweeping some 

 fine gravel or cinders in the interstices of the turves. 



Walls, — These must not be less than nine inches 

 thick, otherwise they will cool so quickly as not to 

 forward the ripening of the fruit and wood so rapidly 

 as is desirable. They are quite as efficient in this 

 respect, if not more so, w^hen built nine inches wide, 

 but hollow. They should have a far projecting 

 coping on the top, for this not only checks the radia- 

 tion of heat from the wall, but is a protection from 

 strong wind and heavy rains, which are especially 

 liable to injure the blossoms. Moreover, they facili- 

 tate the use of netting, &c., as will be more fully 

 particularized in the section devoted to " Shelters." 



Another most important point is the quarter of the 

 compass the wall should face. A south-east aspect 

 is decidedly preferable to a south-west one for peaches. 

 If, however, the border is not too wet, and if the trees 

 are properly trained, they ought to succeed very well 

 on a south-west aspect. The heavy rains to which 

 they are then exposed are injurious when they occur in 

 the blossoming season ; but if the border is sufficiently 

 permeable, the rain, always comparatively warm from 

 that quarter, is beneficial, and far preferable to artifi- 

 cial watering. The vigour of shoots produced on this 

 aspect is generally such as to require them to be 

 trained in a direction nearly horizontal ; and when so 



