TREE 

 TRUN-K 



I ! 



*•-. 



\ N \ ^ / / 



* 



Ffg. 76^. fF/ien the wave length is greater than the size 

 of the object {here a tree trunk), the echo, or scattered 

 sound moves out in all directions. The solid lines indi- 

 cate the original sound, the dashed lines the echoes, 

 and the width of the lines the intensity of sound. 



79 



