20 GREENHOUSES 



Temporary hotbeds are sometimes made 

 by piling the manure on the surface of the 

 ground and placing a shallow frame on top. 



Fig. 6. Plan for temporary hotbed 



This form is wasteful of manure, and the 

 settling of the pile is likely to warp the frame 

 so that the sash will not fit tightly. It is 

 most often used when a hotbed is needed and 

 a pit has not been dug the previous fall. 



Another method is to dig a pit somewhat 

 larger than the frame. This is filled with 

 manure to a little above the ground level. 



Fig. 7. Type of hotbed used when a large amount of heat 

 is required for a long time 



