THE WALLS. 211 



growth of trees, and affording the greatest facilities 

 for training them. We liave often, however, had walls 

 erected in whole or in great part of stones ; and when 

 the stones were good, and kept down to a proper size, 

 we have found the walls little inferior to those com- 

 posed of brick. In good gardens a considerable por- 

 tion of the best walls should be constructed with flues 

 and furnaces, so that they may be artificially heated in 

 spring and autumn — in spring to protect the blossom, 

 and in autumn to aid in maturing the fruit, and what 

 is perhaps of equal importance, to ripen the fruit- 

 bearing wood for the following year. We may add, 

 though the remark perhaps belongs to practical horti- 

 culture, that in autumn artificial-heat is often applied 

 only during the night. This is improper ; for light, a 

 main agent in perfecting vegetable life, is then absent. 

 When the fire-heat is employed during the day, it co- 

 operates with the solar heat and light in the elaboration 

 of the juices of the fruit and foliage, and its action 

 may be equivalent to the reduction of several degrees 

 from the latitude of the place. Good flues, with proper 

 furnaces attached, have been found to be superior to 

 hot-water pipes as means of heating walls. These 

 pipes, when placed within internal cavities, unless 

 they be very numerous, and their sides extremely thin, 

 emit a heat too feeble to produce an appreciable effect 

 on a large surface of wall. 



]<fotc. — The above paragraph is of no account in our 

 American climate. — Ed. 



The Fruit Garden. — This department is so fre- 

 quently and so properly united to the kitchen-garden 

 that it scarcely requires a separate notice. The site 

 and soil which suit the one will generally be found 



