WALLS, FORM OF. 



553 



WALLS FOR GARDENS. 



the longer and stronger the slabs, the 

 fewer the brackets required, and vice 

 versd. An iron water trough runs along 

 in front, to convey the water into a drain 

 at the end. A great drawback to such 

 copings is, that the trees are deprived of 

 the natural rains and dews. This, how- 

 ever, may be remedied, to some extent, 

 by syringing. Such brackets would be 

 invaluable for applying temporary copings 

 of wood for a few weeks in spring and 

 autumn. Notwithstanding all that has 

 been written against the practice, there 

 can be no doubt that it is desirable to 

 afford protection to the surface of wall 

 trees when in blos- 

 som. No copings, 

 wide or narrow, per- 

 manent or temporary, 

 will shelter them 

 from cutting frosts 

 driven in upon them 

 at that time by a 

 sharp wind. Of course, 

 every gardener is fully 

 aware of the great 

 importance of thinning 

 both wood and fruit, 

 getting the former FIG. 3. BRACKET FOR 

 thoroughly matured, TEMPORARY COPING. 

 and preserving the tree in the most robust 

 health ; but it is difficult to see how this 

 precludes us from protecting the blossoms 

 in the spring. Good summer culture will 

 doubtless secure a good show of fruit, and 

 endow the tree with sufficient strength 

 to bring it to maturity ; but it never has, 

 and never can, enable the tender blossoms 

 of peaches and apricots to withstand a 

 frost of 2 without protection. The great 

 merit of the covering suggested above 

 consists in the facility wit'h which it can 

 be removed and applied at pleasure ; for 

 it is better not to protect at all than to 

 apply a permanent covering of any de- 

 scription. The artificial tenderness and 



extra liability to the attraction of insects, 

 in consequence, would be more disastrous 

 than the frost itself. No valid objection 

 can, however, be urged against temporary 

 protection, applied only in cases of abso- 

 lute necessity, and at no other time. So 

 particular are some gardeners upon this 

 point that they have sallied out to place 

 copings or coverings of some sort over 

 the trees even at midnight when the 

 weather has been uncertain. 



Walls for Gardens. 



Necessity for Walls. The garden wall 

 is as the setting to the gem ; without its 

 inclosing fence the garden would be un- 

 distinguishable from the neighbouring 

 fields, and its contents exposed to the 

 depredations of man and beast, as well as 

 to the " pitiless pelting " of every storm. 



Conservative Power with regard to 

 Warmth. But besides the protection it 

 affords, the properly constructed garden 

 wall has other important conservative 

 duties. Dr. Wells, in his interesting ex- 

 periments on the origin of dew, found 

 that a thermometer protected by a hand- 

 kerchief sustained horizontally over it 

 marked a temperature from four to six 

 degrees higher than the corresponding 

 instrument placed in the open ground. 

 The wall and its coping exercise a con- 

 servative power in preventing the radia- 

 tion of heat in the one case which the 

 handkerchief exercises in the other. The 

 wall performs another equally important 

 office; during the heat of the day it 

 absorbs the sun's rays in a ratio pro- 

 portioned to its aspect and inclination to 

 the sun ; and, in common with all heated 

 bodies, it radiates its heat in a ratio pro- 

 portioned to the square of its distance ; 

 so that if an object placed a foot from 

 the wall receives i of heat from it, at 

 one inch it will receive heat equal to 

 144. The reflection, also, of all un- 



