THE CONSTRUCTION OF FARM-BUILDINGS AND COTTAGES. 265 



five to thirty feet in width. The following are suitable dimensions of 

 the timbers : 



Rafter-box a, made of cast iron. 



Suspension-rod b, 2 inches in diameter, made of wrought iron ; i nut. 



Struts cc, 6 inches square. 



Wall-plates d d, 6 inches by 4 inches. 



Pole-plate e e, 6 3 



Rafters//, 10 6 



Small rafters g g, 3 3 



Tie-beam h h, 12 6 



Ridge-piece m, 7 



Purlins n, G 











In fig. 95 is shown a king-post truss. This is a very good form of 



roof, and may be advantageously used at different spans, varying, of 

 course, the size of the timbers to the span. The following are the sizes 

 suitable for different spans : 



for a Span Twenty feet wide. 

 Wall-plates 66, . . . 5 inches by 3 inches. 



Tie-beam c c, . 

 Pole-plate d d, 

 King-post e e, . 

 Rafters//, 

 Struts g g, 

 Purlins h h, 

 Small rafter i t, 

 Ridge-pole j, 



9 

 5 

 4 



4 

 4 

 6 

 4 



7 



4 

 5 

 4 

 4 

 3 

 4 

 3 



For a Span Thirty feet wide. 



Wall-plates, .... 5 inches by 5 inches. 

 Tie-beam, . . . .10 6 

 Pole-plates, .... 6 6 



King-post, 5 v 5 



6 4 



