83 



which will also require two years ; this method will mean 

 a four years rotation. 



The great influence which the taking away of as thin 

 a strip of bark as possible has in the long run, is shown 

 by the above mentioned examples and may be separately 

 elucidated. 



Supposing that on two trees a half herringbone is 

 applied, on two adjacent quarter-surfaces ; one tree is 

 tapped by a workman (A), who makes 15 cuts per inch. 



The other tree is worked by a more experienced 

 tapper (B), who makes 30 cuts per inch. With both trees 

 the distance between the side cuts is 1 2 inches, when 

 the tapping takes place each alternate day. Tapper A, 

 with 15 cuts per inch gets over i inch in 15 X 2 =. 30 

 days ; he, therefore, taps off 1 2 inches yearly, and after 

 a period of one year, he has tapped both quarter sur- 

 faces. B, with 30 cuts per inch works over i inch in 

 30 X 2 = 60 days ; after one year, B has thus tapped 

 only half of each quarter surface, whereas he has 

 obtained as much rubber as A. While A in order to 

 work four years, can only tap one quarter surface, B 

 can tap during the same period two quarter surfaces 

 and can, therefore obtain from the same tree twice as 

 much as A. 



4. REMARKS ABOUT THE SUITABILITY OF THE TREE 

 FOR TAPPING. 



Ill order to ascertain whether a tree is suitable for 

 tapping, the girth is measured; the reason of this dimension 

 being considered decisive for the suitability is obviously 

 that with very thin trees, the side cuts would not be 



