296 Modern Improvements in Horticulture. 



the direct force of the north winds ; the second, because the 

 quality of land dechvious towards the east, is generally supe- 

 rior to that on any other direction ; and, in these northern la- 

 titudes, our earliest productions are checked and retarded by 

 our long, cold nights ; the sooner the sun's influence is re- 

 ceived in the morning, therefore, the greater is the advantage ; 

 and though his influence is sooner lost in the afternoon, this 

 is considered a convenience, after the heat of a warm, clear 

 day ; and even in the moderate weather of the spring months, 

 it prepares the plants for any extreme cold which may happen 

 in the following night. Some practical men there are, who 

 rather prefer an aspect two points to the westward of south, 

 because the garden would be less exposed to east winds, which 

 are equally noxious with those from the north, and because the 

 walls would receive a greater share of the afternoon sun, to act 

 as a defence to the trees, during the cold of the ensuing night. 

 With regard to situation, there are most palpable errors com- 

 mitted in confounding the ideas of shelter and warmth, two very 

 different things ; and, however necessary it be, that a garden 

 should be sheltered from violent winds, it does not follow that 

 such spot should also be the warmest : in fact, we often find 

 the contrary to be the case, it all depending on the dampness 

 or dryness of the soil. A low degree of heat is always generated 

 in proportion to the quantity of evaporation ; consequently the 

 damp and most sheltered valley, or the swampy hollov^^ on a 

 hill, are invariably found colder, and, consequently, more hable 

 to the hurtful effects of frost, than the more elevated and drier 

 knolls of the surface ; and not only from the intensity of the 

 cold, but from the susceptibility of the plants in such places, 

 respectively. Thus then experience would advise that an ele- 

 vation of not less than 65 feet above the level of any swamp 

 or river, is found to be, throughout two-thirds of our seasons, 

 far more favourable to vegetation in gardens, than lower situa- 

 tions, however sheltered they may be. But if a peculiarly dry 

 spot can be found in a valley, and especially if it be intersected 

 by a tide river^, and though but little elevated above, it should 



• The impulses of a tide river on the atmosphere are always found to moderate 

 the cold of winter ; and as such places have also the cold-repelling effects of crowded 

 population and sea breezes, vegetation is less liable to suffer from frost, notwithstand- 

 ing the air may be more humid than that on the hills at a distance. 



