PROPAGATION BY MEANS OF CUTTINGS 



85 



the pipes and up one side of the box past the end of the par- 

 tition, and down the other side. A fire in the stove causes the 

 water to circulate through the tank and impart to the bed a 

 genial warmth. 



Various tanks are designed to rest on the pipes in a green- 

 house. The principle of their construction is essentially the 

 same as of those already described bottom heat, a tray of 

 water, and a bed of soil. Earthenware tanks are commonly 

 employed, but an 

 English device, Fig. 

 84, is made of zinc. 

 It is about 7 inches 

 deep, and holds an 

 inch or two of water 

 in the bottom. A 

 tray 5 inches deep 

 sets into the tank. 

 The water is sup- 

 plied through a fun- 

 nel at the base. 



A useful propa- 

 gating-box inside 

 a greenhouse is 

 seen in Fig. 85. 

 It is placed where 

 good bottom heat 

 is provided, al- 

 though no special 

 installation is made 

 for the purpose. 



T i i FIG. 85. Greenhouse propagating-box. 



In such a box 



draughts may be avoided, a uniformly moist air may be 

 maintained, and the heat may be regulated. It is specially 

 useful for tropical things, as nepenthes and many others. 



