242 VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 



the sashes ; h h h^ are square tubes of wood, penetrating the 

 soil to the chamber beneath, to let the heat rise up into the 

 space confined within the sashes and the wall ; the number of 

 these openings depending entirely upon the weather, and the 

 season of forcing. They may be closed with a lid when the 

 sashes are removed. From the foregoing description, it will be 

 perceived that an erection of this kind has all the advantages 

 of a house, — at least as far as grape-growing is concerned, — 

 without the consequent expense, and when once all the mate- 

 rials are properly adjusted, they can be removed, or replaced, by 

 almost any gardener, without the aid of a tradesman. The 

 rafters are merely fastened to a plate of wood, about one foot 

 broad, and two inches thick, by means of iron pegs, as at e, 

 in the end section, and also at the bottom to another plate, sim- 

 ilar to the one above, and fitted into the posts at /; the sashes 

 are fixed to the rafters by means of a latch, or thumb-screw, 

 placed within reach of the operator, for the facility of admitting 

 air. This is effected by letting down the sashes to any distance, 

 and supporting them by notched brackets, or letting them down 

 to the ground, if necessary, as shown by the dotted line, at /. 



This method may be adopted without having any cavity 

 beneath the border, and, of course, will be cheaper, although we 

 would decidedly prefer such a cavity, did circumstances permit. 

 The advantage of hollow walls, warmed by some method, has 

 been long well known to gardeners, and so highly are they 

 thought of in England, that scarcely any garden of consequence 

 is without them. Indeed, in the majority of seasons, the culture 

 of the vine, peach, nectarine, apricot, and fig, — even on walls, — 

 would be a very precarious and uncertain business, although 

 the method of covering such walls with portable glass has but 

 very lately been brought into use, and, now that glass is cheaper 

 in that country, is almost certain to be extensively applied to 

 this purpose. In one or two cases we have seen this method 

 adopted with astonishing success, and without any cavity, or 

 any other preparation than the common border and wall of the 

 garden. In one place we had forty feet of a wall thus covered 

 with spare sashes ; the space included some peach and fig 

 trees, in excellent bearing condition, and well set with buds, 



