404 



PLANT-HOUSES. 



consider a model house for this purpose. 

 We may here also observe that lean-to 



Fig. 553. 



¥ a m 









1 



i 

 1 







1 



houses are, of all others, the worst adapted 

 for heaths, as the plants draw towards 

 the light in front, while the opposite side 

 becomes naked and deformed from want 

 of it. Turning the plants frequently will 

 not remedy this defect ; besides, vegetable 

 physiologists can assign reasons why this 

 is injurious to them. In building a com- 

 plete heath-house, cisterns should be pro- 

 vided for collecting all the rain water 

 that falls upon the roof, and even for 

 containing a greater quantity if conve- 

 nient, as no plants suffer more from water 

 impregnated with mineral substances than 

 the heaths. For this purpose a cistern 

 should be placed under the stage, and 

 covered over to prevent too much evapo- 

 ration in winter ; but, in summer, it may 

 be left uncovered with advantage. 



In the section above is shown top and 

 bottom ventilation, to be used during 

 winter, when opening the side or roof 

 sashes would be inexpedient. The plants 

 are arranged on the centre and side tables 

 in the usual manner — the largest, of 



Fig 



course, occupying the centre platform. 

 As all span-roofed houses present angular 

 gable-ends, and as these are the points of 

 entrance, we have here shown what we 

 consider to be an improvement— namely, 

 a lobby or porch, (a on ground-plan,) 

 which is separated from the body of the 

 house by a glass partition, and may be 

 furnished with seats, or occupied with 

 large specimen plants. Fig. 554 shows 



Fig. 554. 



the elevation of one of the ends, which, 

 on account of the form, has a fixed roof. 

 The ventilators in the parapet wall are 

 also shown, a a a a, as well as the door 

 opening as high as the sides of the 

 house. 



Fig. 555 shows the elevation of another 

 span - roofed heath - house, the sides of 

 which are glass sashes running on rollers, 

 and fixed rails set on top of the stone 

 plinth, the sashes being made to pass 

 each other, as shown in several figures in 

 this work. The ridge should also be 

 made to open for ventilation. As the 

 whole of the sides and ends may be 

 removed during summer, sufficient venti- 



