322 



FORCING GARDEN. 



inclination to that end of the house- from Avhich the 

 water can he more easily drained. 



Similar expedie;its were long ago employed, in the 

 heating of forcing-pits, by the late Mr. John Hay, of 

 Edinburgh, a garden architect of great judgment and 

 experience. Fig. 2T represents a recent variety of 



Fi<<. 27. 





this mode of supplying surface and bottom heat, by 

 discharging steam into flues and chambers filled with 

 stones. The steam is admitted by small pipes run- 

 ning along the central pit, in channels about four 

 inches deep, and of the same width. These channels 

 are crossed by others at right angles ; and at the 

 points of intersection the steam is permitted to escape 

 by two small holes, one on each side of the pipe. The 

 pits must have a water-tight paved bottom, with a de- 

 clivity of one inch in ten feet. The sides and covers of 

 the channels are loosely jointed, and are permeable by 

 the ste'am. Stop-cocks are attached to the pipes, so 



