174 PORTABLE, TEMPORARY, AND MOVEABLE STRUCTURES. 



hole for the iron pin which secures the wooden coping. To these brackets 

 the coping-boards are secured by broad-headed 

 iron pins, passing through corresponding holes, 

 ft, in the board and bracket, a slip of iron, or 

 " spare-nail," being then introduced through an 

 eye in the lower end of the pin. The upper edge 

 Fig. lu. iron bmcket for support- of the board is slightly bevelled, so as to fit as 

 ing a temporary wooden coping, closely as possible to the under side of the coping 

 of the wall, in order effectually to obstruct the radiation of heat, 

 and the ascent of warm air. From this coping, woollen netting of various 

 kinds, common netting, such as fishermen use, bunting, and thin can- 

 vass, have been let down, and tried experimentally, in the course of 

 the last fifteen years ; and we are informed by Mr. Thompson, that after 

 repeated trials, the thin canvass was found the preferable article for utility, 

 appearance, and duration. This description of fabric costs about 4d. per 

 yard, procured from Dundee. It requires to be joined into convenient 

 lengths, or into the whole length of the wall to be covered, and bound with 

 tape at top and bottom, and to have loops or rings sewed to it at top, by 

 which it is secured to small hoops screwed to the upper side of the coping- 

 boards. These hooks serve also for attaching the ends of pieces of twine, 

 which are stretched down to pegs driven in a line four feet from the bottom 

 of the wall. These twine-rafters are stretched at intervals of twelve feet, 

 and support the canvass at a uniform slope, the appearance being that of an 

 elegant light roof, reaching to within three feet of the ground. The coping- 

 boards are put up before the blossom-buds of the peach-trees have swelled so 

 much as to exhibit the tips of the petals ; and before the most forward buds 

 open, the thin canvass (or netting, if that should be preferred) should be at- 

 tached to the hooks. The covering is generally put up about the beginning 

 of March, and it remains on without being opened or altered, till all danger 

 from frost is over, which is generally, in the climate of London, about the 

 middle of May. The coping is entirely removed at the same time as the 

 canvass, because the trees are found to thrive much better when exposed to 

 perpendicular rains and dews. The canvass is found to be of great utility in 

 bright sunny weather, when the trees are in full blossom ; for the peach and 

 other stone fruit, which in their native country blossom at an early period 

 of the season, whilst the air is yet cool, do not succeed so well in setting 

 when the blossoms are exposed to as much as 100, which they frequently 

 are, against a south wall. The thin canvass admits also plenty of air ; while 

 woollen netting, which it might be thought would admit still more air, was 

 found to render the leaves too tender, in which case they suffer from the in- 

 tensity of the light when the netting is removed. Common thread netting 

 is not liable to produce this effect, being much more airy ; and this netting 

 has the ad vantage, when not placed farther than a foot from the wall, of ad- 

 mitting of the trees being syringed through it. Very little syringing, how- 

 ever, is required till the trees are out of blossom, and none while they are 

 in blossom ; and when the space between the canvass and the wall is nine 

 inches wide at top, and four feet wide at the bottom, as in the Horticultural 

 Society's garden, the syringing can be very well performed in the space 

 within. Perhaps it would be an improvement in the case of the Horticul- 

 tural Society's wall to have the coping as much as eighteen inches wide, as 

 no frost, unless very severe indeed, would injure the blossoms of fruit-trees 



