528 On the Cultivation of Grapes on Fhied Walls. 



The bearing branches of the vines are about two feet six inches 

 apart ; the longer branches of the vines, occupying the lower part of 

 the wall, bear only on the upper half of their length ; all the others 

 on their whole length. 



Twenty or twenty-five clusters of Black Hamburgh Grapes, I 

 consider sufficient for each vine covering a space of wall twelve feet 

 by ten. Muscadines being much smaller, double that number of 

 clusters is allowed on each vine. 



Our flued wall is figured and described in the Gardeners Maga- 

 zine, vol. 8, p. 670. I may however state in what respect it differs 

 from those of the common construction. In the latter, the first 

 or lower flue is deepest, the others decreasing in depth as they 

 ascend, in order to give an equality of heat to the surface ; but this 

 is not accomplished in a satisfactory manner, for the under flue is 

 often found over-heated before the upper one is sufficiently warm. 

 The object is much better accomplished by our method, which 

 consists in having a damper placed between the lower and second 

 flues, immediately over the space where the smoke and heated air 

 enter from the furnace. By this means a part of the smoke and 

 hot air is admitted to the upper flues, while the remainder is made 

 to pass through the two under ones, after which it unites again 

 with that part ascending from the damper to the upper flues. 

 The damper regulates the admission of heat to the top. When 

 the damper is entirely withdrawn the whole heat, or nearly all, 

 goes to the upper flues ; the lower and third flues should be 

 deepest ; ours run thus : lower flue two feet six inches deep, second 

 flue two feet, third flue two feet three inches, fourth or upper flue 

 one foot six inches deep. 



Flued walls upon the common construction would be much im- 

 proved by having a damper placed in a similar way to regulate the 

 heat. 



