222 Description, with Plans of a Hot Wall 



of each division, except that furthest from the fur- 

 nace, as at mm, which by permitting the warm air ac- 

 cumulated at the extremity nearest the furnace to 

 diffuse itself, will tend to render the heat commu- 

 nicated to the exterior surface more uniform. 



Fig. 3. Transverse section of the wall as at B (Fig. 1) ; n, 

 furnace with a double iron, and an ash-pit door ; o, air 

 flue on the top of the furnace, covered with a flag 

 stone, and connected with the air flue p, correspond- 

 ing with c, (Fig. 1 ) A wooden hatch hinged at q, to 

 the flag stone, covers the furnace pit, rr (in this and 

 the other figures) cleaning holes closed with bricks ; 

 s t square cast iron chimney top, set diagonally to the 

 line of the wall, having a lifting damper, and a wire 

 and ring, or chain attached, by pulling down which 

 the damper is raised, and the ring, or link of chain 

 slipped upon a hook fixed in the wall, keeps it in 

 its place ; t, square stone bases, to which the chim- 

 ney top is secured. 



Fig. 4. Transverse section of the wall as at A (Fig. 1); u, a 

 space left between the arch and flag-stone cover of 

 the furnace, to prevent the escape of heat ; v, vacuity 

 opposite the furnace, corresponding with e ( Fig. 1 ) ; 

 w, a recess on the outside of the wall in front of the 

 first turn of the smoke flue, 1£ inch deep, fitted with 

 a wooden trellis, to which the branches of the trees 

 are trained. The rods of this trellis are kept three- 

 eighths of an inch free of the wall, to permit of 

 tying ; x, narrow chamber, as described at /(Fig. 1.) 



