PORTABLE, TEMPORARY, AND MOVEABLE STRUCTURES. 133 



raised six inches above the box at top and bottom, or it may be 

 raised three or six inches at the back, and not raised, or raised only 

 three inches in front, so as to admit more or less air at pleasure, and 

 yet throw off the rain ; the sash being in any of these cases held firm in 

 its place, so as not to be liable to be disturbed by wind. The pivots 

 which fit into the notches are square, in order to admit of their being 

 mounted on rafters of different kinds, so as to form coverings to 

 frames, pits, or even forcing-houses. Supposing, says Mr. Forsyth, a 

 bed of violets, running east and west, in the open air, twelve feet 

 long and three feet six inches wide ; drive seven notched pegs two 

 feet apart down the centre of the bed to stand one foot above ground, 

 and seven down each side at the same distance apart, but only four 

 inches out of the ground ; then, to make the sides and gable ends, 

 take a piece of turf four feet by four feet, shaped out with the edging- 

 iron, and taken up with the turfing or floating spade, an inch and a 

 half thick, of the proper shape, so that it may be set on edge and kept 

 so by a peg on each side, and having the green side out ; when th 

 lights are put on with every alternate one higher than and embracing 

 the iron edges of the two under it, you will have a very elegant little 

 flower-house, which a labourer might erect in an hour with sixpenny- 

 worth of building materials, and the finished structure would have 

 thus every other light hinged and ready to admit air or allow of water- 

 ing and gathering flowers IIKC a complete forcing-house. We regard 

 tnis as promising to be one of the most useful and economical inven- 

 tions that have been introduced in horticulture for some time. This 

 box may be used in the open ground for forcing sea-kale, rhubarb, 

 and for a variety of other purposes. The most efficient of all substi- 

 tutes for hand-glasses are the common barless ground vinery and the 

 cloche. The various " protectors" recently invented are decidedly 

 inferior to these. 



Canvas coverings for glazed structures or detached plants require 

 for the most part to be in framed panels, as well to keep them tight as 

 to throw off the rain, and to prevent them from being blown and beat 

 about by the wind. To render the canvas more durable, it may btf 

 oiled, tanned, or soaked in an anti-dry-rot composition. When applied 

 to cover the glass sashes of frames or pits, it should be in panels in 

 wooden frames of the size of the sashes ; and this is also a convenient 

 and safe mode of forming temporary structures for protecting standard 

 plants or trees; but by suitable arrangements, to be hereafter 

 described, canvas or netting for protecting walls may be hooked on 

 and fastened without wooden frames. This is done in a very efficient 

 manner in the garden of the Horticultural Society of London, to pro- 

 tect a peach- wall. The stone coping of this wall projects over it 

 about an inch and a half, with a groove or throating underneath. 

 Coping-boards nine inches broad, fitted to join at their ends by means 

 of plates of iron, are supported on iron brackets built into the wall. 

 Fig. 108 shows one of these brackets, in which a is an iron which is 

 built into the wall, the thickness of a board below the stone coping ; 

 and b, the hole for the iron pin which secures the wooden coping. To 



