Roofs for Farm- Buildings. 



125 



of greater cost, than would be required with an appropriate intro- 

 duction of iron into the truss. This will be shown when 1 treat 

 of roofs of mixed materials. 



The timber roofs suitable for yards and wide spaces are shown 

 on Sheet 3. They are three in number, viz. : Fig. 11, a roof 

 with a span of 50 feet, the cost of Avhich will be found to be '61. 

 per square, or 6Z. 15^. 6c?. per square of ground (10 x 10) 

 covexed. Fig. 12, a roof divided into 25 feet spans, supported 

 on wooden storey posts, the cost of which will be 4/. 18^. per 

 square, or 5/. 14s. Id. per square of ground (10 x 10) covered 

 — which shows that by adopting two spans for one in timber- 

 framed roofs, the price is reduced very considerably ; and thirdly 

 a roof of somewhat novel construction. In this example the 

 principals, which have a bearing of 24 feet, are placed at intervals 

 of 12 feet. The trusses are framed with a glass front of rough 

 agricultural glass. This arrangement, which secures a perfect 

 light throughout the yard, is shown by the plan and sections of 

 Fig. 13. It will be found to cost 5Z. 4s. 2d. per square, or 

 6/. 19s. Id. per square of ground (10 x 10) covered. 



Timber and Iron Eoofs, framed j)arthj of Wood and -partly 



