68 



To render the instrument easily portable, the gimlet G 

 can be taken o£E and placed within the hollow cylinder CC, 

 of which the caps are removable. 



As the tube is forced into the trunk of a tree a cylinder 

 of wood is cut out. On withdrawing the gimlet the cylinder 

 can be easily pushed out of the tube and.the ring-markings 

 on it counted. Well-formed fairly cylindrical stems of 

 various girths should be operated upon, and care should be 

 taken that the instrument proceeds into the trunk towards 

 the centre. 



