ON THE CONSTRUCTION OF WALLS. 69 



Stones, or gravel ; bat, on the other hand, to counter- 

 balance this advantage, if the aspect be east or icest^ 

 the sun will shine longer on the upper part of the wall 

 than on the lower part, in consequence of which the 

 surface of the wall will be found, in general, pretty 

 equally heated in all its parts. But if the aspect be 

 souths the solar rays during the summer will strike 

 the entire surface of the wall at the same instant of 

 time, unless there be some local impediment; and in 

 this aspect, therefore, the lower part of the wall will 

 always enjoy an increased degree of warmth from the 

 reflection of the ground. Hence, grapes growing 

 within two or three feet of the bottom of a wall facing 

 the south, will, in general, ripen from ten days to a 

 fortnight earlier than those growing on the upper part 

 of it. There is a disadvantage, however, in training 

 grapes near the ground, as it respects their remaining 

 on the vine after being ripe. If grapes can be kept 

 perfectly dry, they will hang on the vine, and mi- 

 prove in flavor, for a long tmie after they are ripe ; 

 but if dampness or moisture of any description reach 

 them, the consequences are quickly seen in the decay 

 of the berries. After the middle of October, therefore, 

 it will be found a difiicult matter to preserve grapes 

 that hang within two feet of the ground, on account 

 of the damp exhalations that continually arise from 

 the soil at that period of the year. 



If walls be built for the express purpose of producing 

 grapes, the most judicious expenditure of the materials 

 will be in the erection of several low walls, not more 

 than six feet high, in preference to a small number of 

 very high walls. For the purposes of pruning and 

 training, and the general management of the vines, 

 walls of this height are far more convenient than those 

 of a greater height ; and if built to run directly north 

 and south, the entire surface of both sides of each wall 

 will be available for the training of the vines ; and as 

 such walls need not be built at a great distance apart, 

 an astonishing quantity of grapes may be thus an- 

 nually grown on a small extent of ground, by the 



