THE FORCING GARDEN. 



567 



latter furnace is not often 

 in use, its connection with 

 the other is cut off by a 

 damper, at the point of 

 junction at (d). 



The height of these 

 houses is only nine feet 

 from the ground to the top 

 of the back wall. The 

 rafters are of wood, as are 

 also the sashes, and are 

 placed at about four feet 

 apart centre from centre. 

 The front sashes («), in the 

 accompanying end eleva- 

 tion, are only one foot six 

 inches high, and slide past 

 each other in the process 

 of giving air, the middle 

 end sash {b) also slides for 

 the same purpose. The 

 sill of the door (c), and 

 the back path of the house, 

 are on a level with the 

 outer surface of the ground. 

 The front border (d) is 

 raised above it considera- 

 bly, a provision judged 

 necessary on account of 

 the damp bottom. The 

 furnaces are placed in the 

 back sheds, and are sunk 

 three feet below the sur- 

 face {h h in the ground 

 plan), to give them a 

 sufficient draught. Pine- 

 houses constructed upon 

 the above principle, have 

 given the greatest satis- 



