HORTICULTURE. 



239 



by putting in the covers of the dampers, and 

 fixing two wooden divisions across, at the extremities 

 of the furnaces. In these places, potatoes may be for- 

 red in early spring ; or, if a taste for fine flowers be in- 

 Hulpt 'irle and the double Cape jasmine (Gar- 



ettnia flfiriitv, L.), which are not ra-ily brought to blos- 

 som, may here be made to flower, ! \ j>l n-ing the pots 

 among wet motses, (hypmm*,)the moi-t heat thus sup- 

 plied proving very congenial to the plant. From the 

 spaces over the top of the furnaces the heated air can 

 at pleasure be directed into either of the two iuccesaktl 

 houses, being admitted by removing one or other of the 

 covered dampen at rf, d, Fig. 1. Plate CCCXI. 



There are niches along the back wall of the pine- 

 stove, nearly opposite to the middle of each sash. They 

 are narrow on the outside, but are bevelled inwards 

 to at least doable their exterior width. The bevel- 

 led sides are plastered, and covered with a trellis; 

 on these, grape vines are trained, the principal shoot, 

 after reaching the roof, being conducted down the 

 rafter, as far as the first row of pine plants in the 

 back of the pit. To these recesses two sets of shutters 

 are adapted, one for the outside, the other for the in- 

 During winter the outer shutter is removed, and 

 the inside shutter employed. The vine, after being 

 pruned, is led without, and fixed there during winter, 

 exposed to the cold of that severe season. When 

 brought in to be forced, the inner shutter is of coarse 

 removed, and the outer shutter put in. The lime of 

 forcing these vine* may thus in a great measure be re- 

 gulated by the gardener, and made to suit the con- 

 veniency of the family. Fig. I. Plate CCCXI. it the 

 ground -plan of this pine-stove. A is the first succae 

 iibn-pt, containing nine sashes ; B the second succes- 

 sion-pit, with ten sashes ; and C the frniting-pit, with 

 eleven suhfs Fig. . is the elevation. I - ii the 

 sectiou ; and, it will be observed, that, for the sake of 

 dfatfnetne**, thU section i drawn to an enlarged scale, 

 nearly double that employed in drawing the ground 

 pin and deration of the stov < ! At t n 



a moveaMe gangway, eighteen inches broad over the 

 glass roof of the narrow pit. for giving access to the 

 front of th> stove. It may be mentioned, that there are 

 two return* of the flue beneath the pathway at the hack 

 of the pic The heated air i< drawn from between torn 

 two flue, by mean, of ostmeul covered dampers, o, *, 

 fee. in Fig. I. ; the covers being only pot on while tike 

 workmen are ehanfintj the tan in the pit, or oo similar 

 occasion*. The small holes seen in the back wall of 

 the ground plan, Fig. I. mm, tee. communicate with 

 .vide* of the floe on the side next to the back 

 wall. Those seen in the curt or back wall of the tan- 

 i ! i ill with the cavity of the nW neat 

 and those in the path-way 66 with the cavity 

 between the floes. I* this way, heated air is drawn 

 odes of the floes at thirteen places on the 

 back wall of the house, and at ten places on the curb 

 of the pit 



The line efgk i, Fig. * in Plate CCCXI. extended 

 to the north wall, thews the declivity of the ground on 

 which the pine-stoves are placed. Nearly opposite to 

 the do.*- in the liack wall of the pine-stove there is a 

 door in the garden wall, leading to the pine-shed, where 

 the plants are kept hi time of shifting. In front of the 

 PfcW *u*ei-'. i may be noticed, are situated die general 

 feremg.pit, the melon-pits, and the cucumber framas. 



Before leaving the subject of glased booses, we may 

 notice some improvements which have of late years 

 been proposed. 



999, Mr Knight remark-, that where ranthme and 



Fruit- 

 Garten. 



natural heat tlo not abound, the form which admits 

 the greatest quantity ot'li^ht through the least breadth _ _ 

 of fflass, and which affords the greatest regular heat ^ 

 with the least expenditure of fuel, must be the best. 

 It is evident tliat the sun's rays ought to fall as perpen- 

 dicularly as possible on the glass roof; because the 

 quantity of light which glance* off without entering 

 the house, must be inversely proportionate to the de- 

 gree of obliquity with w Inch it strikes upon the surface 

 of the glass. Mr Knight made many experiments to 

 ascertain by what elevation of the roof the greatest 

 quantity of light can be made to pass through it ; and 

 he found that in latitude 5'J, the best angle of eleva- 

 tion is 34. But it cannot be denied, that the rayi of 

 the sun will fall, in a directly perpendicular direction, 

 on this inclined plane, only twice in the year, and then 

 for only very short spaces of time : at all other periods, 

 tht v must fidl in an inclined direction, and never per- 

 pendicular to the plane of the glass. Without expect- 

 ing, therefore, that the rays will ever fall precisely per- 

 pendicular upon it oftener than twice in the year, it is of 

 importance that they should do so as much as possible, 

 during those periods when the influence of the sun i* 

 most desired. Mr Knight (in Horl. Trait*. Lend. vol. i. 

 p. 100.) and the Rev. Mr Wilkinson (same volume, 

 p. 162.) do not agree as to the proper inclination of the 

 glass-roof: instead of 84, proposed by the former, tin- 

 latter would have the angle 45. It seems unnecessary 

 to detail the reasons assigned by either writer. 



240. It has been remarked by Sir George Mac- 

 ken lie, that if a form for the glass roof can be found, 

 Midi that the rays will be perpendicular to tome part 

 r>t it during the entire period of the sun's shining, 

 not on two days, but on every day of the year 

 form must be considered the best. Thi form is to 

 be found in the tpltert; and he proposes the quar- 

 ter segment of a globe, or a semi-dome ; though, to 

 catch the sun at all times, the segment would have to 

 correspond with the greatest segment of the circle which 

 the sun describes. He does not propose to bring each 

 pane of glass into the form of a small segment of a 

 sphere ; this would not only be expensive, but unneces- 

 sary. The sire of a glaaed bouse of this kind can scarce- 

 ly with propriety exceed a radios of fifteen feet, that is, 

 thirty feet of length for training. The plan, elevation PLATE 

 and section of a vinery constructed on the principles thus cxcxif. 

 saggvMed by this ingenious and scientific bortiruh 

 have been published by the Landon Horticultural 

 ety in the second volume of their Transactions : anil in 

 Plate ( ( ( Ml. we have given these, with considerable 

 improvement* since made by the author. It has been 

 found, that the frame for the glass-roof may eai . 

 formed of ribs of hammered iron ; each rib consisting of 

 three slips of iron, such as shewn at full size at Fig. 4. 

 The ribs are fixed in an iron plate at the bottom. The 

 distance bet wem them at the base is about fifteen inch* 

 es; and when the gores contract to half that width, 

 every alternate rib may stop. The word gore, we may 

 remark, is that commonly used fur a slip of any mate- 

 rial so cut, as when joined to others to form a g'lobe or 

 any round figure. The frame-work might also be made 

 of wood ; but the wrought iron is not only much cheap. 

 er at first, but far more durable. The under frames 

 may be about thirteen feet high ; they are rivetted into 

 an iron ring at top, and made tast all round to the coping 

 and upright wall, fron rods may be placed for supports 

 Mi, x,x,i, ' thought necessary. The width 



of the panes at the bottom is about a foot, diminishing 

 to six inches at the second set of ribs ; when they begin 

 again at one foot, and contract upwards to four inche*. 



