356 



FRUIT-HOUSES. 



carried parallel to the side walls, and 

 return when they approach the door, 

 which is placed in the centre of the 



Fig. 493. 



opposite end. Ventilation is effected in 

 cold weather by opening the ventilators 

 a a in the side walls, and the ridge, 

 which is constructed upon the principle 

 laid down in the section Ventilation. 



The side ventilators a a are 3 feet by 12 

 inches in the clear opening, and are fur- 

 nished with malleable-iron frames, fixed 

 on the face of the inner side of the side 

 walls, and forming a margin round them. 

 These frames are forged with a groove 

 three-eighths of an inch in breadth, and 

 three-quarters of an inch in depth all 

 round their inner edges — the lower grooves 

 being furnished with two small iron rol- 

 lers each, upon which rest thin plates of 

 sheet iron equal in size to the ventilators, 

 including the depth of the grooves. These 

 plates are neatly fitted to the frames, 

 and made to slide along the rollers by 

 being attached to an iron rod, 1 inch in 

 diameter, extending the whole length of 

 the house. This is acted upon at one end 

 by a screw or worm, which, on turning in 

 one direction, draws each of the sliding 

 plates more or less forward, according to 

 the quantity of air that may be required. 

 A counter movement shuts them up again 

 simultaneously. Thin plates of iron are 

 used for this purpose, as being more dur- 

 able, and not liable to swell when damp, 

 as well as not liable to warp. To stiffen 

 them, however, without much increasing 

 their weight, two ledgers, or cross-bars of 

 iron plate, three-eighths of an inch thick 

 and an inch in breadth, should be fastened 

 to their inner surface, of such a length as 

 will clear them of the top and bottom 

 edges of the frame. This ventilation, it 

 is obvious, may be increased, from an 



opening of half an inch, to the whole 

 extent of the ventilator. 



In warm weather, the side-lights b may 

 be partially or wholly opened, and may 

 be made to slide past each other as in 

 ordinary cases, or hinged on the north 

 side, as exemplified in the cherry-house 

 at Frogmore, or hung on pivots at their 

 centres, or hinged at top and pushed 

 outwards. As the roof is intended to be 

 fixed, the opening in the ridge must be 

 sufficiently large to admit of a free cur- 

 rent ; and as by this mode of ventilating 

 the opening extends the whole length of 

 the roof, the width need not, even in this 

 the very extreme case, be more than 10 

 inches. The tumblers should be capable 

 of throwing the capping to the height of 

 15 inches. 



A shelf for strawberries may be placed 

 at dd; but it should not be close over the 

 pipes, as is often done, for this would 

 interrupt the radiation of heat upwards. 

 The trees, we would propose, should be 

 kept in large pots or boxes, so that they 

 may be removed when the fruit is ripe, 

 and be replaced by others. In such a house 

 figs might be grown throughout the year. 



Fig, 494 is a section of the span- 

 roofed house for cherries in the royal 



Fig. 494. 



gardens at Frogmore. It differs little 

 from the preceding, except in so far 

 as it wants the lower ventilation, which 

 we hold to be of very great importance, 

 especially during the early part of the 

 season, when the winds are often cold 

 and frosty, and not in a fit state to blow 

 in upon the tender blossoms, foliage, or 

 shoots. The ridge ventilation in this 

 house is just as it ought to be — the 

 opening and shutting lid of the ventila- 

 tion being hung upon a centre, by which 



