PINERIES. 



341 



Esq., of Dublin. It is upon a principle 

 different from most others, and has had 

 its share of criticism, and in some respects 

 has been unfairly dealt with. 



Fig. 458 is a section of this house, a 

 is the hot-air chamber ; b front walk, 

 alongside of which run hot-water pipes ; 

 c back walk, also with hot-water pipes, 

 and brackets over them, on which the 

 melon and cucumber boxes are placed. 

 Along the other side of this path, but in 

 niches cut in the wall, stand tubs or boxes 

 with dwarf Musa plants, the foliage of 

 which canopies over the passage, d roof 

 trellis for vines; e upright supports to 

 which melon and cucumbers are trained ; 

 f external front pathway, to prevent the 

 border from being trodden upon, and to 

 protect the stems of the vines, as will be 

 hereafter noticed. 



Fig. 459 is a ground-plan of the same 

 house on a smaller scale, and also of the 



Fig. 459. 



heated vine border in front, a is pit for 

 pines ; b back passage showing the niches 

 for the Musas ; c front passage ; d vine 

 border; e e air- flues ; f hot-water-pipe 

 chamber for heating the border. 



This house is 60 feet in length, 14^ 

 feet in breadth, and the same in height, 

 from the floor-level to the glass. The 

 roof is slightly curvilinear, and of metal. 



Bottom heat is produced by introducing 

 hot-water pipes into the chamber usually 

 filled with tan or leaves; the floor of 

 which, being made quite level, is rendered 

 capable of holding a shallow body of wa- 

 ter to produce evaporation, and to coun- 

 teract the drying heat of the hot-water 

 pipes — a judicious arrangement. This 

 chamber is roofed over with Kyanised 

 timber, 3 inches broad and 2 inches deep, 

 leaving spaces of 1 inch between them. 

 Over this is laid about 8 inches of heat- 

 absorbing materials — as brickbats, stones, 

 &c. — with a covering of fresh turf, the 

 green side undermost, and over all 2 feet 

 of half-decayed leaves, into which the 

 pine plants are plunged. Mr Niven, like 

 most hothouse builders, till of late, used 

 timber as a covering for the heated cham- 

 ber, which of all coverings is decidedly the 

 very worst, not only on account of its non- 

 conducting properties, but also from its 

 liability to decay — against which Kyan's 

 preparation is no safeguard. In such 

 cases decay goes on much more rapidly 

 than when the timber is exposed to the 

 air, and placed in a dry atmosphere: and, 

 which is worse, this decay is going on un- 

 perceived; and while the mind of the 

 owner is trusting to the infallibility of his 

 prepared beams, down the whole mass 

 comes, carrying with it his whole stock 

 of " the king of fruits." 



We have repeatedly stated in the vari- 

 ous sections of this work the danger of 

 employing wood for such purposes, while 

 slate and pavement are so much prefer- 

 able as to durability, and less expensive 

 in the first instance. Mr Niven found 

 that it took four days to heat this vault, 

 and the plunging material above it, to the 

 temperature of 100°. This is not at all 

 strange, considering the obstruction the 

 heat met with in the timber covering. It 

 would have taken two days to have heated 

 the whole, even had slate or pavement 

 been used ; but this is no objection to the 

 principle, as, when once heated, it will 

 retain its heat, and be maintained for a 

 long time with a very gentle fire. 



The hot-water pipes are so arranged 

 that the atmosphere of the house and the 

 pit may be wrought either separately or 

 together. Ventilation is effected by ven- 

 tilators in the front wall and also in the 

 back, which admits of the roof being un- 

 broken — a very important matter when 



