WALLS, ESPALTER-RAILS, AND TRELLIS-WORK. 



179 



470. The foundations of garden- walls should be at least as deep as the 

 ground is originally dug or trenched. The wall is sometimes supported on 

 arches ; but this is not in general desirable, more especially in walls built 

 in the direction of east and west, because the roots of the trees planted on 

 the one side of the wall are liable to extend themselves to the border on the 

 opposite side, which not being exposed to the same temperature as that on 

 the other side, the excitement which they receive from atmospheric tempera- 

 ture must necessarily be different, and consequently unfavourable to growth 

 and the ripening of fruit and wood. 



471. The copings ofwalls, for ordinary purposes, should not project more 

 than two or three inches, because a greater projection would deprive the 

 leaves of the trees of perpendicular rains in the summer season ; and in 

 spring the trees can be protected from the frost by temporary wooden 

 copings, as already mentioned (463). In order to admit of fixing these 

 wooden copings securely, iron brackets should be built mto the wall imme- 

 diately under the coping : or, where temporary rafters are to be fixed to the 

 wall for supporting sashes, stones, such as fig. 116, may be built in, to which 



the rafters may be fitted and fixed by a 

 tenon and pin, as indicated in fig. 117. 

 Along the front border, or row of stone 

 or iron posts, not rising higher than the 

 surface, may be permanently fixed, on 

 which a temporary front wall or plate, 

 for the lower ends of the rafters, may 

 be placed. The garden-walls for ar- 

 rangements of this kind should be flued. 

 >.for fixing temporary rafters, stones for fixing rafters can only be 

 wanted on the south sides of east and west walls, because glass is seldom 

 placed before walls with any but 



a south aspect. Iron brackets, ~"1 



to support temporary copings, r^r " 

 may be placed on all aspects ex- 

 cept that of the north. The per- 

 manent coping is generally form- 

 ed of flagstone, slate, artificial 

 stone, tiles or bricks, and raised 

 in the middle so as to throw the 

 rain-water equally to each side ; 

 and in the case of stone, a groove 

 or throating is formed under- 

 neath, an inch within the edge, 

 to prevent the water from run- 

 ning down and rotting the mor- 

 tar. Where the coping is very 

 broad, and formed of flagstone, 



Fig 117- Mode of fixing temporary rafters. 



it is sometimes hollowed out along the middle, so as to collect the rain-water, 

 from which it is conveyed to a drain along the foundation of the wall by 

 pipes ; but this mode is only necessary in the case of conservatory walls. 

 Where no trees are planted on the north side of an east and west wall, the 

 coping is sometimes bevelled, so as to throw the rain-water to the north side 

 as in fig. 117; but this can never be advisable where trees are trained there. 



