Creeps Sjjstem of Pruning Forest Trees. 



451 



or stuntedness of its growth. But, supposing it then to have 

 twelve regular tiers of branches, or to be thirteen years old, it 

 is evident, that, for a number of years to come, by only taking 

 off one tier in a year, the part of the tree covered with branches 

 will be much greater than that part of the trunk which will be 

 cleared of branches. This will be more distinctly shown in the 

 following table. In it the statements are made at intervals 

 of four years, for the sake of brevity ; the growth of the tree, 

 too, for the sake of simplicity, is assumed to be the same in each 

 year, namely, 15 in. This, I am well aware, is much less than 

 the annual growth, especially of properly pruned trees ; neither, 

 indeed, is the growth constant, but varies with the age of the 

 tree and other circumstances. The assumption, therefore, here 

 made, is taken merely because it is a convenient one for illustrat- 

 ing the effects of this system of pruning. 







Sh 







-a 



si 







III 



III 



■ssf 



pq a 



c > 

 ^ rt o 

 o t- a 



cqg 



i|^ 



8 go 

 -«1 



gth of the 

 from whii 

 Branches 

 ; been re 

 moved. 



At 15 ft. in height, and sup- 



S 





|o2 



12;° 



Hi 



Len 



Part 



the 



hav( 



1 



Feet. 









Feet. 



Feet. 



posing the tree to have 12 















tiers of branches - 



15 



12 



12 







15 







In 4 years afterwards 



20 



16 



12 



4 



15 



5 



In 4 years more 



25 



20 



12 



8 



15 



10 



In 4 years more 



30 



24 



12 



12 



15 



15 



In 4 years more 



35 



28 



12 



16 



15 



20 



In 4 years more 



40 



32 



12 



20 



15 



25 



In the last line of the table it will be seen that, at thirty- 

 three years of age, at the assumed rate of growth, the tree will 

 be 40 ft. in height ; it will have had in all thirty-two tiers of 

 branches, of which twelve are still remaining, and twenty re- 

 moved ; and the height of the part of the stem cleared of 

 branches will be 25 ft., and of the part covered with branches 

 15 ft. It is a question of some importance, what proportion 

 the trunk ought to bear to the head, or the part covered with 

 branches, in a full-grown tree. Pontey's proportion, as given in 

 the Woburn beech, is 50 ft. of trunk to 22 ft. of head. Sang 

 gives 50 to 25. The proportion which I have found to be the 

 best, is the trunk to be about three fifths of the whole height, 

 and the head two fifths; that is, in a tree of the size in question, 

 45 ft. of trunk to 30 ft. of head. 



The proportion which the head bears to the trunk in the 

 last line of the above table, is 25 ft. of trunk to 15 ft. of head. 

 But, in the example there given, the assumption is, that the tree 

 has then arrived only at 40 ft. in height. Climate, altitude, 



G G 3 



