KINEALY PRESSURE OF THE WIND ON ROOFS, ETC. 



341 



TABLES. 



Table i gives the values of the horizontal component of the 

 pressures per square foot of inclined surface, as deduced for vari- 

 ous angles by Hutton's formula and also by Duchemin's, when P 

 is equal to 40 pounds per square foot. 



Table 2 gives the normal pressures per square foot of inclined 

 surface, as deduced by Unwin's formula and also by Duchemin's, 

 when P is equal to 40 pounds per square foot. 



Table 3 is designed for the use of engineers and architects, 

 and gives the normal pressure with its horizontal and vertical 

 components upon each square foot of inclined surface when P is 

 assumed as 40 pounds per square foot. 



The Plate shows the two curves represented by the polar equa- 

 tions used to calculate Table 2, drawn to a scale of 16 pounds to 

 the inch. 



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