﻿325 
  

  

  of 
  charcoal 
  varied 
  from 
  9 
  per 
  cent, 
  in 
  one 
  instance 
  to 
  55 
  per 
  cent, 
  

   in 
  another. 
  The 
  average 
  return 
  of 
  charcoal 
  was 
  just 
  under 
  34 
  per 
  

   cent. 
  It 
  is 
  thought 
  that 
  in 
  the 
  highest 
  percentages 
  (one 
  of 
  55 
  and 
  

   three 
  of 
  48) 
  the 
  charcoal 
  must 
  have 
  been 
  damp 
  when 
  weighed 
  and 
  

   a 
  large 
  amount 
  of 
  dust 
  included. 
  The 
  haladi 
  method 
  is 
  as 
  follows 
  : 
  

   The 
  cotton 
  sticks 
  are 
  closely 
  packed 
  into 
  a 
  pit 
  about 
  20 
  inches 
  deep 
  

   by 
  16' 
  8" 
  long 
  and 
  6' 
  8" 
  wide 
  at 
  one 
  end 
  and 
  3' 
  4" 
  at 
  the 
  other, 
  and 
  

   heaped 
  up 
  to 
  a 
  height 
  of 
  about 
  4' 
  2" 
  above 
  ground-level 
  ; 
  a 
  layer 
  of 
  

   straw 
  refuse, 
  several 
  inches 
  deep, 
  is 
  spread 
  over 
  the 
  surface, 
  leaving 
  

   a 
  portion 
  of 
  the 
  narrow 
  end 
  uncovered, 
  which, 
  for 
  choice, 
  should 
  bo 
  

   the 
  end 
  from 
  which 
  the 
  prevaihng 
  wind 
  blows. 
  Three 
  or 
  four 
  ventil- 
  

   ation 
  holes 
  are 
  opened 
  at 
  the 
  sides 
  and 
  the 
  wide 
  end, 
  to 
  regulate 
  the 
  

   draught. 
  The 
  sticks 
  at 
  the 
  exposed 
  end 
  are 
  there 
  hghted, 
  and 
  when 
  

   the 
  fire 
  has 
  got 
  a 
  good 
  hold 
  the 
  end 
  is 
  closed 
  with 
  straw 
  refuse 
  or 
  

   some 
  other 
  damping 
  material. 
  During 
  the 
  process 
  of 
  burning, 
  which 
  

   may 
  last 
  from 
  24 
  hours 
  to 
  3 
  days, 
  water 
  must 
  be 
  frequently 
  applied 
  

   to 
  prevent 
  the 
  kiln 
  from 
  bursting 
  into 
  flame. 
  Messrs. 
  Kingsford 
  

   and 
  Crewe 
  have 
  patented 
  a 
  retort 
  which 
  will 
  convert 
  small 
  lots 
  of 
  

   cotton 
  sticks 
  into 
  charcoal 
  in 
  a 
  few 
  hours, 
  and 
  is 
  capable 
  of 
  making 
  

   from 
  one-quarter 
  to 
  half 
  a 
  ton 
  per 
  day. 
  It 
  can 
  be 
  seen 
  working 
  at 
  

   Gezira. 
  The 
  calorific 
  value 
  of 
  the 
  charcoal 
  is 
  7'420 
  as 
  compared 
  

   with 
  that 
  of 
  cotton 
  wood, 
  2' 
  744. 
  Ordinary 
  charcoal 
  is 
  retailed 
  in 
  

   Cairo 
  at 
  £(E)8 
  to 
  £(E)12 
  per 
  ton. 
  The 
  cotton 
  stick 
  charcoal 
  was 
  

   readily 
  bought 
  at 
  £(E)4 
  per 
  ton 
  and 
  this 
  price 
  more 
  than 
  covers 
  the 
  

   expense 
  of 
  burning. 
  In 
  enacting 
  complete 
  legislation 
  against 
  the 
  

   pink 
  boll 
  worm, 
  it 
  will 
  be 
  necessary 
  to 
  provide 
  for 
  its 
  destruction 
  

   in 
  the 
  field, 
  as 
  well 
  as 
  in 
  the 
  seed, 
  at 
  the 
  time 
  of 
  ginning. 
  

  

  Grohmann 
  ( 
  — 
  ). 
  Die 
  Generation 
  des 
  grossen 
  braunen 
  Riisselkafers 
  

  

  {Hylobius 
  ahietis) 
  und 
  seine 
  Bekampfung. 
  [The 
  large 
  brown 
  weevil 
  

   (Hyholius 
  ahietis), 
  its 
  reproduction 
  and 
  control.] 
  — 
  Tharandter 
  

   Forstliches 
  JahrbucJi, 
  Berlin, 
  Ixiv, 
  no. 
  4, 
  1913, 
  pp. 
  325-361, 
  3 
  figs. 
  

  

  The 
  available 
  knowledge 
  concerning 
  the 
  reproduction 
  of 
  the 
  pine 
  

   weevil, 
  (Hylobius 
  ahietis) 
  and 
  control 
  measures 
  against 
  it, 
  is 
  very 
  

   insufficient. 
  Since 
  1909, 
  the 
  author 
  has 
  made 
  a 
  study 
  of 
  its 
  life- 
  history, 
  

   which 
  has 
  been 
  facilitated 
  by 
  a 
  system 
  of 
  trapping 
  devised 
  by 
  him 
  

   primarily 
  for 
  the 
  destruction 
  of 
  the 
  pest. 
  The 
  trap 
  is 
  made 
  by 
  digging 
  

   a 
  hole 
  measuring 
  about 
  2 
  feet 
  each 
  way. 
  If 
  the 
  soil 
  removed 
  is 
  not 
  

   sandy 
  or 
  loose, 
  it 
  must 
  be 
  reduced 
  to 
  a 
  uniform 
  fineness, 
  free 
  from 
  large 
  

   roots 
  or 
  stones. 
  Eight 
  to 
  twelve 
  posts 
  of 
  fir, 
  with 
  one 
  end 
  sharpened 
  

   to 
  a 
  point, 
  are 
  driven 
  into 
  the 
  hole 
  at 
  regular 
  distances 
  until 
  their 
  tops 
  

   are 
  only 
  about 
  8 
  inches 
  above 
  the 
  edge. 
  They 
  should 
  be 
  about 
  3 
  to 
  4 
  

   inches 
  thick 
  at 
  the 
  top 
  and 
  their 
  length 
  — 
  excluding 
  the 
  sharpened 
  

   point^about 
  32 
  inches. 
  The 
  fine 
  soil 
  is 
  then 
  put 
  back 
  till 
  the 
  hole 
  

   is 
  filled 
  level 
  with 
  the 
  ground. 
  Fir 
  branches 
  about 
  3 
  to 
  5 
  feet 
  long 
  

   are 
  then 
  laid 
  flat 
  on 
  the 
  ground 
  betw^een 
  the 
  posts 
  with 
  their 
  tips 
  

   outwards 
  and 
  their 
  stems 
  inwards. 
  Ordinary 
  soil, 
  freed 
  from 
  very 
  

   large 
  roots 
  and 
  stones, 
  is 
  then 
  strewn 
  over 
  a 
  surface 
  extending 
  from 
  

   the 
  centre 
  to 
  about 
  a 
  foot 
  beyond 
  the 
  posts 
  and 
  packed 
  in 
  round 
  the 
  

   branches 
  and 
  the 
  posts. 
  A 
  stratum 
  of 
  soil 
  about 
  2 
  inches 
  deep 
  is 
  then 
  

   spread 
  over 
  the 
  branches 
  and 
  on 
  this 
  another 
  layer 
  of 
  branches 
  is 
  laid 
  

   as 
  before. 
  This 
  process 
  is 
  repeated 
  until 
  the 
  posts 
  are 
  buried 
  some 
  

  

  