GREENHOUSE STRUCTURES. 



89 



a greenhouse without artificial heat can be made very 

 useful, in fact, even better in inexperienced hands, than 

 one that is heated, if not used before the end of April ; 

 after that date, glass protection alone is sufficient for 

 nsarly all kinds of bedding plants. 



In the diagram of an end section of a simple house, 

 figure 22, the sashes (B and 0} are three feet wide by six 

 long ; the top one is so placed that it can be let down over 



. SECTION OF A CHEAP GREENHOUSE. 



the lower one by weights and pulleys, and thus secure ven- 

 tilation. 



A greenhouse of this kind, twenty-five feet long by 

 eleven feet wide, should not cost more than $1QO com- 

 plete, if plainly built ; that is, without heating. Heat- 

 ing is a difficult matter in greenhouses so attached to 

 dwellings, unless in cases where there is a surplus heat 

 at night, from furnaces or stoves in the rooms adjoining. 

 In such cases, the windows or doors, if low enough, could 



