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mind the girth of the trees which have to be tapped. As 

 a rule, for young thin trees, the single V, or half 

 spiral is chosen ; for trees of middle age and average 

 surface, the half herringbone ; for older trees the full 

 herringbone which is, however, not applied on a half 

 surface, but on a quarter ; and for trees which must 

 be tapped to death the full spiral. When the tapping 

 system has once been chosen, before it is set out on 

 the trees, the distances between the tapping lines must 

 be calculated so as to work round the surface of 

 each tree in a given period which in the case of young 

 trees will be not less than two years, and in old trees 

 four years. 



The speed with which any part of the bark will be 

 tapped off, depends upon the intervals between tapping and 

 upon the dexterity of the tapper. Trees may be tapped 

 daily or on alternate days. An inexperienced labourer will 

 take away more of the bark with each cut, than an 

 experienced one. A tapper can make on an average 

 15 cuts per inch, at least; very dexterous tappers know 

 how to shave the bark down in such a way, that 30 or 

 even a few more cuts, will go to the inch ; this measu- 

 rement indicating the tapped distance along the ver- 

 tical groove. Such tappers, are however, rare ; in a 

 group of 100 men, there were only 7 who could make 

 30 cuts per inch. On an estate where the tapping has 

 been going along for a considerable period, experienced 

 tappers are available and an average of 20 to 25 cuts 

 can be taken ; it may be expected that this figure will 

 increase up to a limit of 30 cuts per inch. 



A single example will suffice to show how distances 

 between the tapping lines are calculated. 



