MECHANICAL PROPERTIES. TABLE 75. Conifers Grown in U. S. (English Units). 



99 



COLUMN NOTES (continued). (7) recommended allowable working stress (interior construction): I tabular value; experi- 

 mental results on tests of air-dry timber in small clear pieces average 50 per cent higher; kiln-dry, double tab alar values; (1 

 repeated falls of so-lb. hammer from increasing heights; 11-12, 2O3.2-mm (8 in.) long specimen* loader! on ends with deformations 

 measured in a i52.4-mm (6 in.) gage length; (12) allowable working stress \ tabular crushing strength; (13) iS2.4-mm (0 in.) long 

 block loaded on its side with a central bearing area of 2s8o.6-mm 2 (4 in 2 ) allowable working stress, j tabular value. (14) so.8-mm 

 by 50 8-mm (2 in.) projecting lip sheared from block; allowable working stress, J tabular value; (15) 63.5-mm (2^ in.) specimen with 

 25.4-mm (i in.) free loaded length; allowable working stress, J tabular value. (16-17) for values in Ibs. multiply values of metric 

 tables by 2.2. 



SMITHSONIAN TABLES. 



