342 



FRUIT-HOUSES. 



metallic roofs are employed. The vines 

 are planted in the border without, and 

 are introduced through the front in 

 rather a novel manner. "At each side 

 of each ventilator," says Mr Niven, 

 " there is an opening for the reception of 

 each vine, which vine is planted, not 

 close to the front parapet as usual, but 

 4 feet from the house, and then taken to 

 it under a front pathway, (/ in section,) 

 in narrow boxes which are made with 

 lids, and open at the ends, and through 

 the opening under the ventilator to the 

 trellis within." This part of the arrange- 

 ment deserves particular attention, as it 

 provides against two evils often attended 

 with the most serious consequences — ■ 



namely, the twisting or breaking of the 

 stems while taking them out or putting 

 them into the house, and also the injury 

 done by frost to the exposed parts of the 

 stem when the sap is rising in winter or 

 spring in the case of early forcing, and 

 before it ceases to flow in autumn, in the 

 case of late crops. Both these evils are com- 

 pletely obviated by this plan, as no part of 

 the vine stem is at all exposed to the air; 

 and the radius thus obtained, of something 

 like 4 feet, besides the width of the ven- 

 tilator itself, another 4 feet, renders the 

 removal out or in of the vines a matter of 

 ease and safety. 



Fig. 460 is a longitudinal section of 

 the external borders of this house, show- 



Fig. 460. 



ing how they are heated by hot water, 

 that heat being derived from the boiler 

 employed for heating the interior, a pre- 

 pared border in which the vines are 

 planted; b hot-water- pipe chamber; c c 

 air-drains. 



Fig. 461 is a section of the same border, 

 and walk in front, a air-drain; b hot- 



Fig. 461 



water-pipe chamber; c drain; d walk in 

 front of border; e border; / pathway 

 along the exterior front of the house, 

 and under which the boxes are placed, 

 for the stems of the vines to lie in, as 

 before described. 



Mr Niven was amongst the first to 

 carry into practice the theory, long ago 

 laid down, of the advantage of heating 

 vine borders; and he appears to lay great 

 stress upon its application, and describes 

 the operation of the plan as follows : — 

 "The chamber containing the pipes is 

 formed along the one end and front only of 

 the vine border, having small minor 

 chambers or drains, 1 foot square, crossing 

 it at regular distances, with open side walls, 

 which may be covered over either with 



short pieces of charred timber, long- 

 shaped bricks, or large slates; the spaces 

 between these minor air-conducting cham- 

 bers to be filled up with broken stones or 

 brickbats. The whole is to be covered 

 over with a stratum of limestone broken 

 very small, and then by a firm thick turf 

 with the grass side down, over which the 

 compost is to be laid to the depth of 2^ 

 feet next the house, and 2 feet at the 

 walk or chamber. Thus, whenever the 

 branches of the vines are introduced 

 inside the house, the valves may be 

 a turned on the outside pipes, and the 

 requisite temperature obtained for the 

 roots. Calculating according to the ordi- 

 nary principles of circulation," Mr Niven 

 " considers that a regular current through 

 the inner chamber will be the result of 

 heating the air in the pipe chambers in 

 front, and also that the heat will find 

 ready access through the open side walls 

 of the cross chambers amongst the stones 

 and brickbats forming the bottom of the 

 border between. At the same time," Mr 

 Niven "proposes having a small plug- 

 hole opening opposite the end of each 

 minor chamber through the front para- 

 pet into the house, so that at any time, if 

 found requisite, the heat derived from 

 the outside chambers may be admitted 

 into the body of the house." As a re- 

 tainer of heat in the border so heated, 

 Mr Niven very wisely proposes to have 



