GLASS STRUCTURES. 



73 



struction of the vrall, beds, etc. Lumber is used in the building 

 shown in the figure, but brick or stone would be more durable, 

 though it would add considerable to the first cost. The posts 

 are three feet apart, extend about two feet below the planks 

 and are braced. The inside rows of posts need not be quite 

 so strong as the outside ones, and need not be braced. When 

 a house is not more than twenty-four feet long it will not be 

 necessary to support the roof in more than one place. This is 

 done by extending two of the middle posts to the rafters. 



In figure 29 is shown a cross section of this greenhouse and 

 the way the sashes and rafters are joined at top and bottom. 

 The sashes are cut so as to fit tightl}' at the top and the plate 

 is beveled a little so as to allow water to run off quickly. 



There are sixteen wooden shutters for covering the sashes 

 on cold nights. These are made the same v\'idth as the sashes 



but six inches longer. 

 One cleat is put on the 

 upper side at one end, 

 and the other on the 

 lower side at the other 

 end. When put on, the 

 upper cleat is against the 

 ridge pole which leaves 

 the shutters clear for the 

 water to run off. They 

 are made of second fenc- 

 ing matched and dressed. 



In this house there is 

 glass over the path, 

 which is not necessary 

 in the lean-to plan, 

 shown in figure 30, where 

 the sash is all on the 

 south side of the path 

 It is important to have 

 crops grow as close tc 

 the glass as may be, and this fact should be carefully borne in 

 mind. This style of house is susceptible of many modifications. 

 It may be used as a lean-to on the south side of the dwelling, 



Figure 30 — Cross section of lean-to green- 

 house hotbed. 



