CULTURE OF THE GRAPE. 127 



of arras, are, first, that, in rough vineyard-culture, there is 

 more or less danger that the growth of the different arms 

 will not be kept separate in actual practice, occasioning 

 some confusion, and unequal distribution of foliage ; sec- 

 ondly, the lower tiers and the ground will be too much 

 sheltered and shaded by the upper tiers, causing a damp- 

 ness, and a lack of circulation of air near the ground ; 

 thirdly, the upper tiers will be exposed to strong cur- 

 rents of wind, which are very injurious ; and, in addition, 

 the expense of building high trellises, and managing the 

 vines upon them, is much greater than in the low system. 

 By a study of fig. 24, any one of ordinary judgment 

 will be able to follow the form that is given, or make 

 such simple modifications ns are desirable for covering 

 the sides of barns, or the roofs of sheds, arbors, &c. To 

 the novice in grape-culture it may be well to mention, 

 what will more fully appear in the chapter on Pruning, 

 that all the upright fruit-bearing wood is annually cut 

 back to one new eye, leaving but the trunk and the two 

 arms at the close of the season. Is this system correct in 

 theory? and what is the practical testimony in regard to 

 it? It is the misfortune of horticultural science that 

 many of its questions cannot be answered with mathe- 

 matical certainty: so much time is required in making 



