lOKClNG DEPARTMENT. 103 



a four-inch wall at the back, the heat of the dung, ap- 

 plied outside, is readily communicated to the bed in 

 which the plants are growing, which keeps a regular 

 bottom heat at their roots. When the rancidity of 

 the dung linings has evaporated, a few holes may be 

 made by a round piece of wood, sharpened at the 

 end, so as to pass more freely through the bed of 

 leaves, or other materials, close to the back wall, 

 which will supply the atmosphere of the pit with a 

 moist heat, when it may appear desirable. This 

 pit is also surrounded by a dung pit two feet wide, 

 and sunk about three feet under the ground level, 

 as will be seen by the Sections. 



3 f 2 



