28 FRUIT AND KITCHEN GARDEN. 



duced. It is presumed that all the walls are to be covered, 

 both within and without, with trees trained en espalier. 



Different portions of the inclosure wall are always built 

 of different heights, and this variation of height is the 

 more necessary when the ground approaches to a level. In 

 such a situation, and when the inclosure does not exceed 

 two acres, the north wall may rise to the elevation of 14 

 feet; the walls on the east and west may be two feet lower, 

 and the south wall need not exceed 10 feet. In larger 

 gardens, the walls are generally made proportionally higher : 

 on the north, perhaps, 16 feet, on the east and west 14, 

 and on the south 12. In several excellent Scottish gar- 

 dens, planned by the late Mr. Hay, such as that at Castle 

 Semple, a piece of building is made to project diagonally 

 outwards from the corners where the walls meet at right 

 angles. This projection is 16 or 17 feet in length. It 

 serves to strengthen the fabric, and at the same time, acts 

 as a brise-vent, breaking the force of the winds which sweep 

 around walled gardens. 



Walls inclined to the horizon have been recommended 

 by Desaguliers. Hoffels, and others ; but, independently 

 of the theoretical objections which might be urged against 

 them, and which, in actual practice, would probably coun- 

 terbalance their supposed advantages, they must be incon- 

 venient from their bulk, or the large space which they oc- 

 cupy 5 and hence they have never come into general use. 

 Where, however, the natural slope of the ground is too 

 great for carrying on the ordinary operations of gardening, 

 sloping terraces may advantageously be converted into a 

 kind of inclined wall, to be faced with slate or some other 

 material that does not readily absorb moisture. 



Bricks afford the best and the most kindly m aterial for 

 garden-walls. Being rough and porous they absorb radiant 



