448 



AGRICULTURAL ENGINEERING 



owing to the fact that they are not only strong in tension 

 but are stiff and make a more rigid structure. 



A curb roof is used, and the rafters, which are usually 2x6's 

 are strengthened at the curb by braces of inch boards or 2- 

 inch pieces cut to fit underneath. The rafters are usually 

 placed two feet apart on the larger barns of this construction, 



;a wisw N 



/0-8' 



/O'-O' 



5 ~-2~*2's- 



;o'-8' 



3^'-0' 



Fig. 290. A sketch of the Shawver barn frame. 



and should have diagonal braces to make the frame more 

 rigid. The Wing joist frame is not adapted to barns over 

 40 feet wide. 



The Shawver Barn Frame. The Shawver barn frame, 

 as now constructed,* consists of bents made up of 2-inch lum- 

 ber and placed 8 to 16 feet apart, on which the wall and rafter 



