230 



HORTICULTURE. 



l-'ruit maturation of the fruit itself, at least in the case of 

 * peaches and nectarines, being left as mucli as possible 



"""^""" * to the influence of the sun and air. The vinery, the 

 peach-house and the fig-house, ought not, in general, 

 to be considered as forcing houses ; but as calculated 

 rather to assist the natural efforts of the plant and to 

 make up for the imperfections of the climate, every 

 possible use being in the mean time made of the natural 

 climate. They may, however, be converted into for- 

 cing -houses, by varying the time of applying the arti- 

 ficial heat; and in this way, not only cherries and 

 strawberries, but grapes and peaches, may be obtained 

 many weeks before the natural season arrive. The 

 pine-apple, which has not yet been spoken of, requires 

 continually an increased, and even high temperature ; 

 while the orange tribe needs little more than to be 

 saved from frost during winter. 



The disposition of hot-houses, in regard to the gar- 

 den and pleasure grounds, has been already spoken 

 of. A suite or range of glazed houses is generally form- 

 ed together, with only glass partitions between them. 

 In this case the green-house is sometimes placed in the 

 middle, and the stoves at each end, so that, during 

 winter, a person may pass into either hot-house with- 

 out opening a direct communication between it and 

 the external air, which, on account of the rarefaction 

 of the air within, is ready to rush in. 



Hot-houses are comparatively of modern invention. 

 They were unknown in the days of Gerarde and Par- 

 kinson, that is, of Elizabeth and James VI. After the 

 civil wars, horticulture seems to have received more at- 

 tention ; but a glazed house, with a furnace and flues, 

 does not appear to have been constructed previous to 

 1684. Sir Hans Sloane, writing in that year, mentions 

 that Mr Watts, gardener at Chelsea Garden, then re- 

 cently instituted, had a new contrivance for preserving 

 tender exotic plants during winter ; " he makes under 

 the floor of his green-house a great fire-plate, with 

 grate, ash-hole, &c. and conveys the warmth through 

 the whole house by tunnels, letting in upon occasion 

 the outward air by the windows." The green-house 

 was thus converted into a stove, or made to answer the 

 purpose of both. Separate houses for plants belonging 

 to very warm climates were soon found to be necessa- 

 ry; and in 1724, Bradley describes a stove or conser- 

 vatory, with flues and every thing in the manner of a 

 modern dry stove. The bark stove was soon afterwards 

 introduced ; the heat resulting from the fermentation 

 of tanners bark being employed, however, in the cul- 

 ture of pine-apples before it was applied to ornamental 

 plants of hot climates. Two kinds of stoves are at pre- 

 sent in common use, the dry stove and the bark stove. 



Dry Stove. 



ry stove, 199. The dry stove is generally constructed with 

 upright glass frames in front, and sloping glass frames 

 by way of roof, extending perhaps to within four feet 

 of the back wall of the house, which space of four feet 

 is commonly covered with slates. The angle at which 

 the glass is made to slope is usually about 35. The 

 floor is raised two feet above the exterior surface, in 

 order to give room for the flues, which if sunk low do 

 not draw freely. The flues are carried to the extremi- 

 ty of the house, and returned several times, according 

 to the length and breadth of the building. They are 

 constructed of fire-brick, and the covering is composed of 

 square tiles, about an inch and a half thick. In Scotland, 

 where sandstone abounds, the covers are usually form- 



3 



Fruit 

 Garden. 



stow 



of flags, two inches or somewhat more in thickness. The 

 flagstones of the Hailes Quarry, near Edinburgh, are 

 excellent for this purpose : the finer laminae from the 

 quarry at Carmylie, in Forfarshire, commonly called Ar- 

 broath pavement, are apt to crack and shiver from expo- 

 sure to heat. They are generally made about 1 8 inches 

 deep, and of nearly equal breadth, and horticultural wri- 

 ters have in general recommended these dimensions; but 

 there can be little doubt that the breadth should be nearly 

 double the depth. Mr Stevenson, civil engineer, found- 

 ing on some experiments made in constructing a dry. 

 ing-house, has strongly recommended this improve- 

 ment. (Scottish Hort. Mem. i. 143.) He observes, 

 that " the flues in general use are of too small dimen- 

 sions ; there is not capacity in them for allowing the 

 heated particles of air to expand ; so that the heat pas- 

 ses rapidly through such narrow flues, and makes its 

 escape with the smoke, in what may comparatively be 

 called a latent state, without being allowed to act on a 

 surface large enough to rob it of its caloric." He far- 

 ther remarks, that an apartment heated with flues of a 

 wide, but shallow form, is less liable to sudden changes 

 of temperature, than where the flues are small ; and 

 that such flues possess the advantage of seldom or ne- 

 ver requiring to be cleaned. The furnace is generally 

 so situated, as that the upper part of the arch is as high 

 as the top of the flue, where the heat is introduced in- 

 to the house. The height of the body of a furnace, of 

 the usual dimensions, is two feet four inches, varying 

 however, according to the slope of the ground ; the 

 width is nearly the same ; the length of it inside three 

 feet ; the door a foot square ; and the length of the 

 back of the furnace two feet. In the dry stove a stand 

 is erected for supporting shelves on which the plants 

 are to be placed ; the stand and shelves together being 

 called the stage. In this stove all kinds of succulent 

 plants, such as cacti, mesembryanthema, stapeliae, and 

 aloes, are preserved, with many other tender plants 

 which do not require bottom heat. 



It may here be noticed, that it having been found 

 that certain parts of hot-houses where one furnace only 

 is employed, are not heated equally -with other parts 

 nearer to the furnace, it has been proposed to convey 

 to these parts heated air from the furnace by means of 

 tinned iron tubes. Nicol and others object to these tubes . 

 resting on the flues,as being apt to diminish the evolution 

 of heat from their surface : they might, however, be car- 

 ried free of them, and certainly deserve further trials. 

 Such tubes, it is to be observed, are only necessary in hot- 

 houses already built. In the constructing of new houses, 

 a small flue, perhaps 2g inches or a brick square, can ea- 

 sily be carried along in the back wall. Heated air drawn 

 from the furnace into this flue can be conveyed to the 

 opposite end of the house, and there admitted by a 

 valve or door at pleasure. Matters must of course be 

 so contrived, that no smoke can pass into this small 

 flue. 



Bark Stove. 



200. The bark stove is distinguished by having a Bark stove. 

 large pit, nearly the length of the house, three feet 

 deep, and six or seven feet wide. This pit is formed 

 with brick walls, and has a brick pavement at bottom, 

 to prevent the earth from mixing with the tan, which 

 would hinder its heating. It is filled with fresh tan- 

 ners bark, well dried ; and in the bark, pots containing 

 plants from the East or West Indies, or tropical cli- 

 mates, are plunged. The bark acquires and long re- 

 tains a moderate heat ; but besides this, it preserves a 



