306 



SCIENCE OF GARDENING. 



Part II. 



and so on, till the wall attains the given height, which in the Netherlands, and some 

 parts of Germany, where these walls prevail, is seldom above ten feet. At Lyons they 

 are often fifteen and eighteen feet. Sometimes a trellis is placed before them, but in 

 general the branches of the trees are fastened by means of wooden hooks of six or seven 

 inches long, which are driven into the walls, and from which twigs or rods are stretched 

 across, from the one to the other. These walls are generally covered with a projecting 

 coping of thatch, or boards ; the latter is much the neatest, and least liable to harbor 

 b 239 



. — 



insects. Peaches are grown on them in France and Germany, but in this country, where 

 the weather is more, variable, and the atmosphere more generally charged with vapor, 

 particular attention requires to be paid to the coping. This attended to, these en pise, or 

 mud- walls, may be useful as shelters to cottagers' gardens, but rarely of much service as 

 sources of wall-fruit. For a more particular account of their construction, see Commu- 

 nications to the Board of Agriculture, vol. ii. ; or Nicholson's Arch. Diet, art. Wall. 



1565. Boarded or wooden walls (Jig. 240. a) 

 are variously constructed. One general 

 rule is, that the boards of which they are 

 composed, should either be imbricated or 

 close-jointed, in order to prevent a current 

 of air from passing through the seams; and 

 in either case well nailed to the battens 

 behind, in order to prevent warping from 

 the sun. When well tarred and afterwards 

 pitched, such walls may last many years, 

 parts or supports formed of cast-iron 



240 



They must be set on stone posts, or the main 

 Nicol informs us (JTalendar, p. 149.) that he 

 has " constructed many hundred lineal feet of wooden walls, which recline considerably 

 towards the north (fig. 240. b), presenting a surface at a better angle with the sun than 

 if they were upright. They are placed on sloping ground, and range in five ranges or 

 lines, due east and west, at the distance of seven yards from each other, the southmost 

 bein<r five feet high, and the northmost seven, composed of imbricated boards, pitched 

 over to give them durability ; the supports are set on (not in) blocks of stone, which are 

 sunk in the earth, and firmly laid on solid foundations, three feet under the ground 

 level." 



1566. Inclined fruit-walls seem to have been first suggested about the beginning of the 

 eighteenth century, by N. F. De Douillier, F. R. S. an able mathematician, author of a 

 work entitled Fruit-walls improved by inclining them to the Horizon, &c. Some- 

 walls were formed at Belvoir Castle on this plan, which Switzer informs us he went to 

 see, but found them damp, and the trees liable to be injured by perpendicular frosts. 

 De Douillier's work, as being the production of a speculative theorist (he was tutor to 

 the Marquis of Tavistock), appears to have been rejected, by Miller, Switzer, Lawrence, 

 and the designers of gardens of that day, but it is replete with ingenuity and mathe- 

 matical demonstration, and well illustrates the importance of sloping walls where they 

 are to be protected by glass or gauze. For exposed walls, it does not appear that 

 this form will ever be adopted, chiefly on account of the difficulty of building them, the 

 inutility of the northern or inferior side, and because, if formed in the most economical 

 manner, they would not serve as fences. In particular situations, as in the case of ter- 

 race slopes, they certainly merit trial ; and if covered in severe weather, there can be no 

 doubt that their surface, by being more perpendicular to the sun's rays in summer, would 

 receive a greater accession of light and heat at that season. In a communication to the 

 Horticultural Society (vol. iv. p. 140.), by Stoffels, gardener at Mechlin, he states, " that 

 he had an opportunity of comparing the effect of a sloping and perpendicular wall in the 

 same garden, for the growth of peach-trees, and that the result was greatly in favor of the 

 former." It appears to us, that for this and other fruit-trees that do not grow very rigid 

 at the root or main stem, a boarded wall which might be inclined at pleasure, to an angle 

 of 45° to both sides of the perpendicular, might be advantageously adopted. In the day- 



