INVESTIGATION OF THE TRANSVERSE STRENGTH IN WOOD 



By KITARO MOEOTO, Assistant Profissor 



Unlike minerals, wood is not homogeneous. Its strength, thus, differs 

 much according to species, moisture content, age, breadth of year rings, 

 as well as number of knots. The strength of wood also is in general 

 influenced by the size of the piece. 



It is important to determine the strength of wood in relation to its 

 moisture content, age, breadth of year rings and number of knots so as 

 to enable the forester to grow such products as are most marketable 

 timber on the one hand, and to furnish the builder with the needed 

 factors in calculating the strength of wood on the other. A full investi- 

 gation of the subject was therefore undertaken by the writer in March 

 1904, and since then the woods commonly offered on the market have been 

 thoroughly tested. It is now a-great pleasure to publish a portion of the 

 results thus obtained : namely those connected with the transverse strength, 

 the investigation of which was terminated in 1906. Further, all the data 

 are given in English measure, since they are commonly used by builders. 



I. Object of the Investigation 



1. Determination of Transverse Strength of Wood 



AND ITS Modulus of Elasticity. 



The strength of wood is distinguished as transverse, tensile, com- 

 pressive, shearing etc. 



As the transverse strength of wood is by far the most important in 

 building and as the determination of the modulus of elasticity is most conveni- 

 ently obtained by the same test, we undertook, first of all, to test this property. 



2. Location of the Heart of the Wood in Relation 



TO its Strength. 



To determine the relation of strength of wood with the location of 

 the heart the test was made with the beams, of which the heart was so 

 placed as to be near the top or else near the bottom. 



