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can be counted. Prom two or three such'borings, on different 

 sides of the trunk, the average number of rings per unit of 

 radius can be ascertained. 



This instrument is a gimlet, consisting of a tube (G) 

 with a very sharp-cutting edge (E). 



To render the instrument easily portable, the gimlet 

 G can be taken off 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. 



