MISCELLANEOUS ARTICLES USED IN HORTICULTURE. 119 



boards together, a space is left sufficient to check radiation, and 

 to prevent the escape of heat by conduction. If boarded shutters 

 could be kept about six inches from the glass, and air excluded from 

 entering at top and bottom and at the sides, radiation would be effec- 

 tually checked, and less risk of the escape of heat by conduction in- 

 curred than when the boards touch the sash-bar ; but this would 

 require great care in excluding the air from the sides and ends. All 

 the frames and pits in the gardens at Syon are covered by boarded 

 shutters, as are all those in the extensive forcing-ground of Mr. Wilmot 

 of Isleworth. Narrow shutters of this kind might be contrived for 

 hothouse roofs, so as to produce a great saving of heat. Canvas 

 would, in many instances, repel wet and check radiation as well as 

 deal boards, and might be put on much quicker ; but the great 

 objection to it is its liability to be disturbed by high winds unless, 

 indeed, it is attached to wooden frames, which occupy as much time in 

 taking off and putting on as wooden shutters, and are much less durable. 



Wicker-work hurdles are useful in gardens for sheltering low 

 plants from high winds, for placing horizontally over seedlings to pro- 

 tect them from birds, and, in various positions, for shading plants. 

 They are constructed of upright stakes fixed in the ground, or in holes 

 in a board, at regular distances of from four inches to eight inches, 

 according to the size of the materials and the dimensions of the hurdle, 

 and these stakes are filled in or wattled with small rods, wands, or spray. 

 When kept dry, they will last three or four years, if the stakes are 

 made of willow, or of any of the soft woods ; and from four to six or 

 seven years, if they are made of hazel, oak, 

 ash, or any of the hard woods. Fig. 90. 



Props for plants vary in form, dimension, 

 and material, from the small wires used for 

 supporting hyacinths in water-glasses, and 

 the sticks of six inches in length used for 

 supporting plants in pots, to cast-iron rods of 

 six or eight feet in length, and pillars, arches, 

 or houses for roses and other climbers, formed 

 of the stems of young fir-trees, of from ten 

 to twenty feet in length, as in fig. 90. All 

 the varieties of wooden props may be re- 

 duced to four kinds : 1. Straight rods with 

 the bark on, but with all the side branches 

 cut off, varying in size from the shoot of one 

 year to the stem of a fir of twenty years' 

 growth. These are used for every purpose, 

 from the tying up of plants in pots to the 

 support of lofty climbers, including between 



these extremes tying up dahlias and stan- p rop s for climbers. 

 dard roses. 2. Branches or stems, with all 



the side branches and branchlets retained, used for the support of 

 climbing annual stems, such as peas, kidney-beans, tropseolums, &c., 

 but only suitable when these plants are grown in the open ground ; 



