12 THE FORCING GARDEN. 



No early vinery should contain too much glass. 

 When I say ' too much/ I mean that there should be 

 none on the cold sides. There is nothing like a good 

 dry brick wall for the back of an early vinery, with but 

 little or no glass at the ends. A house constructed on 

 my plan, i,e. at the angle above named, will be abund- 

 antly light enough without any more glass than what 

 the roof contains, and will be better adapted for main- 

 taining the necessary heat at a less cost. 



In constructing a back wall, it will be -a great ad- 

 vantage in every way to build it according to my 

 method, that is, hollow. A wall constructed on this plan, 

 60 feet long, 12 feet high, and 9 inches thick, will 

 take about 5,360 bricks ; while one of the same dimen- 

 sions built with solid work, as is usually done, will take 

 7,930 or thereabouts. Here then is a difference of 

 2,570 bricks in the first place, and then there is a 

 saving of at least ll. in mason's and mason's labourer's 

 wages and mortar. Nor is this all, for a wall so con- 

 structed is much drier, and therefore of necessity much 

 warmer; the wall is full of chambers of heated air, 

 which continue to give out their contents by night into 

 the house, which is an immense advantage in early 

 work, as by this means a better result is obtained than 

 by a fire-heated flue. In virtue of such a wall, the 

 angle of roof, and the construction of an apparatus 

 like that shown in fig. 6, I may challenge all others, 

 that is, supposing the roof to be double-glazed on my 

 plan, and having the < border protector.' 



