28 



VEGETABLE FORCING 



pipe posts are set in 

 concrete walls and the 

 posts supporting the 

 purlins are also set in 

 concrete. Glass oc- 

 cupies the space be- 

 tween the top of the 

 wall and the gutter or 



Fig. 13. A common form of wood wall sill. side olatC Concrete 



walls are often banked with soil on the outside, to exclude 

 cold. When this is not desired the walls may be given 

 a more finished appearance by applying a thin coat of 

 Portland cement. 



Frame. All wood parts of the frame, including wall 

 plates, eaves-plates, headers, sash bars and ventilating 

 sash, are prepared at the factories, so that the work of 

 erection can readily be managed by a local carpenter or 

 anyone who uses tools efficiently. The same may be said 

 of the iron and truss forms of construction, although they 

 are considered more difficult, and there is greater 

 necessity for the employment of skilled mechanics. 



Wall plate or sill. The size and form of wooden wall 

 sills are quite variable. Different means are used to 

 secure them to the wall, one of the best being 8-inch bolts 

 running through the plates at frequent intervals and em- 

 bedded in the concrete. The lower end of the bolt may 

 be bent to make it more secure in 

 the concrete, and a burr is screwed 

 on the upper end immediately 

 above the plate. Fig. 13 illus- 

 trates a common form of wooden 

 wall sill. 



The eaves or side plates of sep- 

 arate houses vary greatly in dif- 

 ferent forms of construction. The 

 angle iron forms of eaves-plates 

 (Fig. 14) are superior to all 



