UTILIZATION OF ASH. 



'X7 



1. Pores in the summerwood more or less united in lines. 



a. The lines short and broken, occurring mostly near the 



limit of the ring While ash 



b. The lines quite long and conspicuou, in most parts of 



the summerwood Green ash 



2. Pores in the summerwood not united into lines, or rarely so. 



a. Heartwood reddish brown, and very firm Red ash 



b. Heartwood gTayish brown and much more porous Black ash 



MECHANICAL PROPERTIES OF THE DIFFERENT SPECIES.* 



Table 10 gives the results of a large number of tests to determine 

 the mechanical properties of different species of eastern ash from 

 different parts of the country, and Table 11 gives a summary of them 

 in general terms and in order of the relative strength of the different 

 lots tested. Strength ^ is the most important property and therefore 

 the factors which influence it are considered at lengih. 



S'peciflc gravity or weight. — The ashes follow the general law of 

 timber in regard to the relations of mechanical properties and 

 weight; i. e., all the mechanical properties increase in force as the 

 specific gravity of the wood increases. This is not, however, always 

 a straight line relation. 



^ By J. A. Newlin, of the Forest Products Laboratory. 



2 Bending strength and crushing strength, such as are important in beams and posts. 



743G5°— Bull. 523—17 3 



