BUILDINGS FOR HORTICULTURAL PURPOSES. 



113 



can be always found appropriate places for 

 different things ; and it is worth while to keep 

 also different degrees of dampness by artificial 

 means. In the stove or hot-house, Mr. Penns' 

 system for circulating the air is the most ad- 

 visable plan for heating the house. Tliis 

 plan consists of giving off the heated air at the 

 lowest portion of the house, that it may spread 

 up the roof, and, as it falls, returning under 

 the floor or false bottom to the place where 



Fig. 23. 



the fires continue to heat it as it passes 

 from time to time, by which means a rapid 

 uninterrupted circulation is kept up, and 

 greatly contributes to the health of the plants. 

 The section of a hot-hou.se upon this plan 

 would be .something like Fig. 2.3. 



On a large scale, this would be a most 

 effective plan, for there is nothing more simple, 

 and when one of the pits constructed on this 

 plan is clo.sed, the circulation of air is re- 

 markably strong : holes are left, through which 

 air may be admitted at pleasure j but it is not 



often required. The brick-work in the stoAC 

 is more expensive than in a green-house or 

 conservatory, and the false bottom under 

 ^vhieh the cooled air passes from the back to 

 the front™, rather increases the labor ; but in 

 houses in which the tan pits are built, they 

 would form an obstacle to the free circulation 

 of air, if it were not for a grating at the back 

 to let it down under the floor as it cools, and 

 another grating under the pipes to let the 

 cooled air coiue up again between them to be 



warmed again. The wood-work and glazing 

 of a stove is no more than that of a green- 

 house, and the build is much the same, except 

 that the house should be deeper from back to 

 frrnt. The operation of the boiler and pipes 

 is very simple, and may be understood from 

 the foregoing diagram (Fig. 24,) for, turn and 

 twi.st the pipes as you may, all that is re- 

 quired, is, that one end goes out at the 

 top of the boiler, and the other end returns 

 in at the bottom of the boiler. Thus the 



Fig. 25. 



boiler is like two inverted flower-pots, one 

 less than the other, and the water is between 

 the inner one which holds the fire, and the 

 outer one which is exposed. The fuel is put 

 in at top and shut down. The fuel is pro- 

 vided for in the fixing. This boiler would 

 feed hundreds of feet of pipe, and it is ])er- 

 haps the simplest and best of the many jilans 

 for heating horticultural buildings ; due re- 

 gard being had to the capacity and the eco- 

 nomy of the thing, for both are objects worthy 

 of attention. It is easily managed, for when 

 the fire is lighted well, the aperture may be 

 filled to the top and covered over, the regu- 

 lator of the flue being so far closed as to allow 

 of slow steady combustion. If a tank for hot 

 water is preferred to tan in the interior pit, 

 the tank may be made about eight inches 

 deep, or from that to ten, the top must be 

 closed with large slates, cemented together, 

 leaving only one aperture to open at pleasure ; 

 this may be heated by sending the usual iron 

 pipes through the tank ; on the top of this 

 tank may be placed a foot of tan or soil, or any 

 other medium in which to plunge pots, or 

 plant whatever is to be grown. The top of 

 one (Fig. 25,) is open to show the pipes, the 



Fig. 26. 



other (Fig. 26,) closed, to show the slates ; but 

 the water in the tank may come direct from 



