228 GLASS-HOUSES FOR FORCING, 



NARROW GLASS-HOUSES FOR FORCING, PRINCI- 

 PALLY BY FIRE -HEAT OR HOT WATER. 



Par. 30. Glass houses of narrow dimensions 

 for forcing fruit trees principally, are sometimes 

 erected (for forcing with hot water or fire heat) 

 against a south wall eight or ten feet high or 

 more, width about five or six feet, and length of 

 any extent that may be required, the whole 

 enclosed with glass moveable sashes (in proper 

 sloping frames) made to slide up and down as 

 occasion may require, from a low front wall 

 about eighteen inches high, to the top of the 

 back wall ; the pipes for hot water or flues for 

 fire-heat, may be ranged along near the front, or 

 down the middle, or along the back part near 

 the wall, the pipes should be raised a little from 

 the ground, and if heated by flues, they should 

 also be raised on low arches, that by being 

 detached from the ground, the house will re- 

 ceive the benefit of the whole of the heat : the 

 trees may be trained to the wall ; but if the 

 flues or pipes are -carried along the back close 

 to the wall, it will be necessary to have a trellis 



