COLD FRAME 



59 



water, because the plants are grown later in the 

 when transpiration and evaporation is greater. 



season, 



Fig. 17. — A cross-section of a cold frame. 



The cold frame has a few advantages over the hotbed. 

 It is more cheaply constructed, it requires no heating mate- 

 rials and needs no excavation. However, the cold frame 

 cannot be used as early in the season as the hotbed, and 

 it should only supplement the hotbed and not replace it. 



The frames may be movable or stationary. Portable 

 frames are not, as a rule, popular with the larger growers, 

 and the stationary frames seem to give the best satisfaction. 



10. 

 side? 



11. 



12. 



13. 



14. 



15. 



16. 



17. 

 sash. 



18. 



19. 

 take? 



REVIEW QUESTIONS. 



Why are hotbeds and cold frames important? 



Give four advantages of a hotbed. 



Discuss the location of a hotbed. 



What is the value of a windbreak for a hotbed? 



What is the distinction between a natural and an artificial windbreak? 



What exposures are preferred for the hotbed? 



Describe the hotbed pit. 



What is the standard size of the hotbed sash? 



Name the five materials of which the frame is made. 



How much higher must the upper side of the frame be than the lower 



What is the value of crossbars? 



What kinds of hotbed sash are made? 



Give the advantages and the disadvantages of each kind. 



Discuss the two ways of placing glass in the frames. , 



Which method is the best? 



Why is it important to have all frames well painted? 



Name four advantages and three disadvantages of the double-glass 



What is meant by a compost? 



How shoiild the manure be composted, and how long does it usually 



