184 FIXED STRUCTURES FOR GROWING 



description, is the introduction of sheet-window-glass, which, while it 

 is nearly as thick and strong as plate-glass, is not much dearer than 

 crown-glass. The thickness of this glass varies from one-eighth of an 

 inch to something more than one-sixteenth, and either thickness may 

 be used in lengths of from two to five feet. In the grand conservatory 

 at Chatsworth, the panes are three feet nine inches in length, that 

 being the length of the side of the ridge, and they are six inches in 

 width, so that there is no occasion for a lap. Ridge and furrow 

 houses, when this kind of glass is used, may be made nearly air-tight. 

 In the grand conservatory in the Horticultural Society's garden, the 

 same kind of glass is used, and the panes are sixteen inches by twelve 

 inches. This house is remarkably well glazed, and the laps are all 

 puttied. Indeed, if this were not the case, it would be almost impos- 

 sible to heat such a lofty structure with glass on all sides ; but this 

 glass being very even, as well as thick and strong, the laps are not 

 more than three-sixteenths of an inch, and do not retain any water, 

 which, indeed, from the temperature within being seldom greater 

 than that without, is not often deposited on it. Most of the evils 

 of drip and breakage, described in this chapter, are wholly avoided 

 by cutting the glass, and the abolition of putty -glazing, as in Beard's 

 system. 



Water is commonly supplied to plants in hothouses by hand ; but 

 pipes, pierced with small holes, have been arranged under the roof, 

 which, on turning on water from a cistern above the level, will throw 

 down a shower at pleasure. For lofty houses, such as the palm-stoves 

 of Messrs. Loddiges, the inventors of this system, this mode of watering 

 is very eligible, and it might also frequently be adopted in conserva- 

 tories attached to dwelling-houses, the cistern being in the upper part of 

 the house. As a luxury, the noise of the artificial shower, like that of 

 drops of rain in a warm summer's evening when all is arid without, 

 will more than compensate for the expense. The evils incident to such 

 modes of watering are, that all the plants, dry or not dry, get the 

 same quantity. Such expedients are, therefore, not to be recommended, 

 unless for watering the foliage nicely. A much better, because dis- 

 criminate mode of root- watering is to screw a length or two of gutta- 

 percha or india-rubber hose on to a water-pipe or tank, and then, 

 with a conductor, direct a stream of water to any pot or root that 

 requires it. A dexterous use of the finger to stop or regulate the flow, 

 and an exact aim, renders this the most expeditious and efficient mode 

 of watering. As water should never be applied to plants at a lower 

 temperature than the mean of the atmosphere in which they grow, 

 there should be a cistern in every house, of sufficient capacity to 

 supply all the water which can be wanted at any one time, placed over 

 the flues or hot-water pipes in such a manner as soon to be heated by 

 them. In plant-houses these cisterns may be used to a certain extent 

 for growing aquatics ; but in this case only a small portion of water 

 should be taken from the cisterns at a time, so that the addition of 

 cold water may not chill the plants. To prevent the rose of the 

 watering-pot from being choked by the leaves or other matters in such 



