86 

 STRENGTH OF WOODEN BEAMS. (Kidder). 



To use the tables for beams that run less than nominal 

 dimensions. In many localities floor joists as carried in 

 stock are more or less scant of the nominal dimensions, 

 and for such joists a reduction in the safe load must be 

 made to correspond to the reduction in size. For beams 

 ^4 in. scant in both dimensions the safe load may be ob- 

 tained by multiplying the safe load as given in the table 

 by the following factors: 



For beams 1% in. x 5% in. by 1.6. 



2% in. X 5% in. by 2.52. 



1% in. X 6% in. by 1%. 



2% in. X 6% in. by 2.55. 



1% In. X 7% in. by 1.64. 



2% in. X 7% in. by 2.58. 



1% in. X 9% in. by 1.66. 



2% in. X 9% in. by 2.61. 



1% in. X 11% in. by 1.67. 



2% In. X 11% in. by 2.63. 



1% in. X 13% in. by 1.68. 



2% in. X 13% in. by 2.65. 



1% in. X 14% in. by 1.69. 



2% in. X 14% in. by 2.66. 



1% in. X 15% in. by 1.7. 



2% in. X 15% in. by 2.66. 



MAXIMUM LOAD PER SQ. IN. ON DIFFERENT KINDS 

 OF MASONRY FROM BEARING PLATES. (Kidder). 



Kind of L.b. per 



Masonry. sq. in. 



Granite 1,000 



Sandstone (best grade) 700 



Sandstone (soft) 400 



Hard Stone Rubble 150 to 250 



Extra-hard Brickwork In cement mortar 150 to 200 



Hard Eastern Brickwork in lime mortar 120 



Brickwork (common) 100 



Portland Cement Concrete 200 



Sand or Gravel . . 60 



