WAL 



C 818 ] 



WAT 



eighteen inches, from fourteen tip to 

 twenty feet. 



Inclined or Sloping Walls have been 

 recommended, but have always failed in 

 practice. It is quite true that they receive 

 the sun's rays at a favourable angle, but 

 they retain wet, and become so much 

 colder by radiation at night than perpen- 

 dicular walls, that they are found to be 

 unfavourable to the ripening of fruit. 



The Flued-wall or Hot-wall is generally 

 built entirely of brick, though, where stone 

 is abundant and more economical, the 

 back or north side may be of that material. 

 A flued-wall may be termed a hollow wall, 

 in which the vacuity is thrown into com- 

 partments a a a a, to facilitate the circu- 

 lation of smoke and heat from the base, 

 or surface of the ground, to within one 

 or two feet of the coping. Such walls 

 are generally arranged with hooks inserted 

 under the coping, to admit of fastening 

 some description of protecting covers, 

 and sometimes for temporary glass frames. 

 A length of forty feet, and from ten to 

 fifteen high, may be heated by one fire. 

 the furnace of which, b, being placed one 

 or two feet below the surface of the 

 ground, the first course, or flue, c, will 

 commence one foot above it, and be two 

 feet six inches or three feet high, and 

 the second, third,and fourth courses, d, e,/, 

 narrower as they ascend. The thickness 

 of that side of the flue next the south or 



preferable side should, for the first course 

 be four inches, or brick and bed ; and, for 

 the other courses, it were desirable to 

 have bricks cast in a smaller mould; say 

 for the second course three, for the third 

 two and three quarters, and for the fourth 

 two and a half inches in breadth. This 

 will give an opportunity of bevelling the 

 wall, and the bricks being all of the same 

 thickness, though of different widths, the 

 external appearance will be everywhere 

 the same. Enc. Gard. 



WALNUT. Ju'glans. 



WAEDIAN CASE. See GLASS CASE. 



WA'RREA. (Named after F. Warre, a 

 botanical -collector. Nat. ord., Orchids 

 [Orchidacese]. Linn., 20-Gynandria 1- 

 jWonandria. Allied to Grobya.) 



Stove orchids, grown in baskets. See ORCHIDS. 

 W, bidenta'ta(two-tQOt'he6.-Hpj)sd}. Purple.white. 

 September, Caraccas. 1843. 



cya'nea (blue-lipped). 1. White, blue. August. 



Columbia. 1843. 



discolor (two-coloured). Purple and white. 



* Central America. 1854. 



quadra' ta (four-sided). Purple and white. Cen- 



tral Africa. 



rube'scens (reddish). Red. April, Brazil. 1839. 



tri'colur (three-coloured). 2. Yellow, purple. 



August. Brazil. 1843. 



WATER. The best for the gardener's 

 purpose is rain water, preserved in tanks 

 sunk in the earth, and rendered tight 

 either by puddling, or bricks covered with 

 Parker's cement. To keep these tanks 

 replenished, gutters should run round 

 the eaves of every structure in the garden, 

 and communicate with them. Every hun- 

 dred cubic inches of rain water contains 

 mere than four cubic inches of air, of 

 which more than half are carbonic acid 

 gas, and the remainder nitrogen and 

 oxygen, in the proportion of sixty-two of 

 the former to thirty-eight of the last 

 named. 



That obtained from ponds or springs 

 invariably contains matters offensive or 

 deleterious to plants. That known as 

 hard water, containing an excess of salts 

 of lime or magnesia, is invariably preju- 

 dicial, and pond water is scarcely less so. 

 If it be stagnant, and loaded with vege- 

 table extract, it is even worse than hard 

 spring water ; for it then contains car- 

 buretted hydrogen, and other matters 

 noxious to vegetables. These last-named 

 waters, if obliged to be employed to tender 

 plants, should have a pint of the arnmo- 

 niacal water of the gas-works, mixed 

 thoroughly with every sixty gallons, an 

 hour or two before they are used. 



WATER-CRESS. (Nastu'rtittm ojficina'le.} 

 Varieties. Small Brown-leaved, hardi- 

 est; Large Brown-leaved, best for deep 

 water; Green-leaved, easiest cultivated. 



Planting in Water. -The trenches in 

 which they are grown are so prepared, 

 that, as nearly as possibly a regular depth 

 of three or four inches can be kept up. 

 These trenches are three yards broad, 

 and eighty-seven yards long, and when- 

 ever one is to be planted the bottom is 

 made quite firm and slightly sloping, so 



