in which 



M safe load In pounds uniformly distributed. 

 d depth of beam in inches. 

 6 breadth of beam in inches. 

 s = allowable shear in the direction of the grain in 



pounds per square inch. 



EXPLANATION OF THE TABLE OF SAFE LOADS FOR 

 RECTANGULAR BEAMS OF SHORT-LEAF 



YELLOW PINE. 



The table is calculated for an allowable fiber stress, for 

 flexure, of 1,000 Ib. per square inch. 



The deflection coefficients are figured for a modulus of 

 elasticity of 1,-joo.onu lb. per square inch, but may be 

 used for other moduli, after obtaining the corresponding 

 coefficients by proportion as heretofore explained. 



The lower dotted line across the table indicates the 

 limits of spans for which the safe load will produce de- 

 flections greater than 1-360 of the length of the beam, 

 v'alues above the line will give less deflection than this, 

 and those below will give greater, based on a modulus of 

 l.L'oo.ooo lb. per sqinre inch. Similarly, the upper dotted 

 line indicates the limit of deflection corresponding to a 

 modulus of elasticity of 600,000 lb. per square inch. 



The full zig-zag line across the table indicates the limit- 

 ing spans and loads based on the allowable intensity of 

 shearing stress along the neutral axis of the beam. The 

 values above the full zig-zag line correspond to shearing 

 stresses greater than the allowable stress in the direction 

 of the grain of short-leaf yellow pine, while those below 

 the line correspond to shearing stresses less than that 

 allowable. \vl.ich, in this case, is assumed to be 100 lb. 

 per square inch. 



EXPLANATION OF TABLES OF SAFE LOADS FOR 

 RECTANGULAR BEAMS OF WHITE OAK AND 



LONG-LEAF YELLOW PINE. 



The table is compute! for an allowable fiber stress of 

 l.-oO lb. per square inch, for flexure, and the deilr, t im 

 Molents are calculated for a modulus of elasticity of 

 1. .M M i.oOO lb. per square inch. 



The limit for a deflection of 1-360 of the span is indi- 

 cated by the lower dotted zig-~ag line on the tables, the 

 values liciow which << >n rspni'il t > <1. !!. t ions greater than, 

 and those above to deflections less than, the limiting de- 



