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the copings to project much further darkness of its colour, if a proper screen 

 than they are usually made to do, even be then employed. — Johnson's Princ. of 

 as much as twelve inches ; but his rea- Gard. 



soning refers more immediately to the 

 manaizement of wall fruit. 



Inclined or Sloping Walls have been 

 recommended, but have alwavs failed 



It is a practice sanctioned by econo- in practice. It is quite true that they 



my, to build the wall half brick thick, receive the sun's rays at a favourable 



on a nine inch foundation, and to com- angle, but they retain wet, and become 



pensate for its want of strength, a so much colder by radiation at night 



waved form is given. Both the small- than perpendicular walls, that they are 



ncss of its substance and its form, are found to be unfavourable to the ripen- 



found, however, to be inimical to the ing of fruit, 

 ripening of fruit. " The F/ucd-u-all or Ilot-iral!,'" says 



In every instance a wall should never Mr. Loudon, " is generally built entire- 

 be lower than eight feet. The thick- ly of brick, though where stone is 

 ness usually varies with the height of abundant and more economical, the 

 the wall, being nine inches, if it is not back or north side may be of that raa- 



liigher than eight feet; thirteen and a 

 half inches, if above eight and under 

 fourteen feet; and eighteen inches, 

 from fourteen up to twenty feet. 



Fruit trees will succeed quite as well 

 against a stone wall as against a brick 

 one, although the former is neither so 



tcrial. A flued wall may be termed a 

 hollow wall, in which the vacuity is 

 thrown into compartments, to facilitate 

 the circulation of smoke and heat, from 

 the base or surlace of the ground, to 

 within one or two feet of the coping. 

 Such walls are generally arranged with 



neat in appearance, nor can the trees hooks inserted under the coping, to ad- 

 be trained in such a regular form upon mit of fastening some description of 

 it as npon the latter. The lastdisadvan- protecting covers, and sometimes for 

 tage may be in a great measure remc- temporary glass frames. A length of 

 died by having a wooden or wire trellis forty feet, and from ten to tifleen high, 

 affixed to it. — Gard. Chron. may be heated by one fire, the furnace 

 If it be desirable that the roots of the of which, being placed one or two feet 

 trees should benefit by the pasturage below the surlace of the ground, the 

 outside the wall, it is very common to first course or flue will commence one 



build it upon an arched foundation. 



toot above it, and be two feet six inches. 



Colour has very considerable influence ' or three feet high, and the second, third, 

 over a body's power of absorbing heat, and fourth courses, narrower as they 

 If a thermometer on a hot summer's ascend. The thickness of that side of 

 day, be exposed to the sun, it will indi- the flue, next the south or preferable 

 cate a temperature of about 100°; but if side, should for the first course, be four 

 the bulb be blackened with Indian ink inciies or brick and bed, and for the 

 or the smoke of a candle, it will rise other courses, it were desirable to have 

 from ten to twenty degrees higher, bricks cast in a smaller mould : say for 

 The reason for this is tli;it the polished the second course three, for the third 

 surface of the glass reflects some of the two and three (juarters, and for the 

 sun's rays, but the blackened surlace ' fourth two and a half inches in breadth, 

 absorbs them all. Blue absorbs all but This will give an opportunity of bevel- 



the blue rays — red all but the red — 

 green and yellow all but those of their 

 own name — and white reflects all the 

 rays. The lightest coloured rays are 

 the most heating, therefore light co- 

 loured walls, but especially white, are 

 the worst for fruit trees. The ther- 

 mometer against a wall rendered black 



ng the wall, and the bricks being all of 

 the same thickness, though of difl'erent 

 widths, the external appearance will be 

 everywhere the same." — Enr. Gard. 



Mr. Paxton has the following excel- 

 lent observations upon Conservative 

 Walls, or walls so constructed as to 

 shelter trees trained against them from 



by coal tar, rises 5^ higher in the sun- winds, and other natural modes of 

 shine, than the same instrument sus- rapidly lowering the temperature: — 

 pendcd against a red brick structure of " In forming a conservative wall, it is 

 the samii thickness; nor will it cool necessary that it should have a south or 

 lower at night, though its radiating | a south-western aspect. It is also desi- 

 power is increased by the increased' rable, in order to give it an ornamental 



