﻿SILVICrLTI 
  RAL 
  NOTES. 
  

  

  31 
  

  

  increase 
  begins 
  to 
  fall 
  off. 
  The 
  merchantable 
  contents 
  of 
  Shortleaf 
  

   Pine 
  under 
  8»» 
  years 
  of 
  age 
  is 
  somewhat 
  uncertain, 
  as 
  the 
  diameters 
  

   become 
  too 
  small 
  for 
  accurate 
  calculations. 
  Between 
  the 
  ages 
  of 
  60 
  

   and 
  100 
  years 
  the 
  average 
  yearly 
  increase 
  in 
  merchantable 
  contents 
  

   amounts 
  to 
  6.25 
  board 
  feet, 
  and 
  between 
  60 
  and 
  200 
  years 
  to 
  7.71 
  

   board 
  feet. 
  (See 
  tig. 
  7.) 
  

  

  Relation 
  between 
  diameter, 
  total 
  height, 
  merchantable 
  length,* 
  crown 
  

   length, 
  and 
  clear 
  length." 
  (See 
  fig. 
  8.) 
  — 
  The 
  principal 
  point 
  of 
  inter- 
  

   est 
  connected 
  with 
  this 
  diagram 
  is 
  the 
  rapid 
  increase 
  in 
  the 
  length 
  of 
  

   merchantable 
  timber 
  obtained 
  from 
  trees 
  of 
  15 
  to 
  2-1 
  or 
  25 
  inches 
  in 
  

   diameter, 
  and 
  the 
  small 
  additional 
  length 
  obtained 
  from 
  trees 
  of 
  greater 
  

  

  10 
  SO 
  30 
  40 
  50 
  60 
  70 
  B0 
  90 
  100 
  110 
  ISO 
  130 
  140 
  150 
  

  

  ABC- 
  V 
  CARS 
  

  

  Fig. 
  6. 
  — 
  Diagram 
  showing 
  the 
  height 
  growth 
  of 
  Shortleaf 
  and 
  Loblolly 
  Pine 
  on 
  the 
  basis 
  of 
  age. 
  

  

  diameters. 
  The 
  merchantable 
  length 
  is 
  greatest 
  in 
  proportion 
  to 
  the 
  

   total 
  height 
  when 
  the 
  tree 
  has 
  a 
  diameter 
  of 
  2<» 
  inches. 
  In 
  this 
  case 
  

   a 
  little 
  more 
  than 
  one-half 
  of 
  the 
  total 
  height 
  is 
  merchantable. 
  

  

  By 
  comparing 
  the 
  curves 
  tor 
  clear 
  length 
  and 
  for 
  merchantable 
  

   length 
  it 
  will 
  be 
  seen 
  that 
  for 
  trees 
  below 
  19 
  inches 
  in 
  diameter 
  the 
  

   merchantable 
  length 
  is 
  less 
  than 
  the 
  clear 
  length, 
  while 
  above 
  that 
  

   diameter 
  the 
  reverse 
  is 
  true. 
  In 
  other 
  words, 
  in 
  trees 
  over 
  19 
  inches 
  

   in 
  diameter 
  breasthigh 
  (21 
  inches 
  on 
  the 
  stump) 
  the 
  logs 
  are 
  cut 
  up 
  

   into 
  the 
  crowns, 
  the 
  distance 
  to 
  which 
  the 
  cut 
  extends 
  into 
  the 
  crown 
  

   increasing 
  as 
  the 
  diameter 
  of 
  the 
  tree 
  increases. 
  

  

  ■Merchantable 
  length 
  is 
  the 
  total 
  length 
  of 
  merchantable 
  timber; 
  in 
  other 
  word?, 
  

   the 
  sum 
  of 
  the 
  log 
  lengths. 
  

  

  b 
  Clear 
  length 
  is 
  the' 
  distance 
  from 
  the 
  ground 
  to 
  the 
  point 
  where 
  the 
  branches 
  of 
  

   the 
  crown 
  l>egin. 
  

  

  