39$ 



SPECIFICATIONS 



Timber. 



mediate points, wherever the shearing per square inch exceeds 



the stress allowed by the following formula : 



Allowed shearing stress = 12,500 90 d -r- t 

 where d = depth, and t thickness of web plate. 



41. Compression 'flanges of plate girders shall be stayed 

 transversely when their length is more than thirty times their 

 width. 



42. The allowable stresses in timber purlins and other 

 timbers shall be taken from Table II. 



TABLE II. 

 ALLOWABLE WORKING UNIT STRESSES, IN POUNDS, PER SQUARE INCH. 



Corrugated Steel. 



The allowable stress, P, in timber columns longer than 15 

 diameters shall be obtained by means of the formula 



p = c- . -L 



100 d 



where C = value in column 4 above ; / = length of column and 

 d least width of column, both in feet. . 



COVERING. 



43. Corrugated steel shall generally have 2.y 2 inch cor- 

 rugations when used for roof and sides of buildings, and i>4 

 inch corrugations when used for lining buildings. The mini- 



