88 Notices of Communications to the Horticultural Society, 



by sliding shutters at the top of the wall. The flue is covered 

 at top with hollow tiles, and water is poured upon the front 

 part of it by means of an iron pipe passing from the outside, 

 for the purpose of raising steam within the chamber and pit. 

 The following ground plan and section of the pit will illustrate 

 the above description. 



Explanation of the Figures. 



A, Air holes for ventilation, passing through the front wall, 



three inches in diameter, and three feet apart. 



B, Flue rising gradually to the turn C, and then proceeding 



to the chimney D. 



E, Damper at back and front, to be opened when necessary, 



for the escape of the heated air from the chamber. 



F, Wall to support the oak beams, built of open chequered 



brick-work, to allow of the free passage of the air. 



