﻿BATtREN 
  ISLAND. 
  # 
  

  

  extent 
  tlian 
  the 
  south-eastern. 
  But 
  • 
  there 
  is 
  no 
  corroborative 
  evidence 
  

   tending 
  to 
  show 
  that 
  any 
  such 
  change 
  of 
  axis 
  has 
  ever 
  taken 
  place, 
  and 
  

   I 
  believe 
  the 
  peculiarity 
  under 
  discussion 
  should 
  be 
  ascribed 
  mainly, 
  if 
  

   not 
  entirely, 
  to 
  a 
  bodily 
  subsidence 
  of 
  the 
  north-western 
  half 
  of 
  the 
  vol- 
  

   cano. 
  

  

  Most 
  probably 
  the 
  ancient 
  crater 
  was 
  originally 
  formed 
  by 
  the 
  

   blowing 
  away 
  of 
  the 
  upper 
  and 
  central 
  part 
  of 
  the 
  cone 
  by 
  a 
  great 
  

   explosive 
  eruption 
  1 
  (since 
  which 
  time 
  the 
  crater 
  has 
  been 
  modified, 
  

   and 
  enlarged, 
  by 
  denudation), 
  and 
  the 
  subsidence 
  just 
  referred 
  to 
  

   was 
  very 
  probably 
  a 
  concomitant 
  feature 
  of 
  the 
  same 
  catastrophe. 
  

   A 
  parallel 
  instance, 
  on 
  a 
  far 
  greater 
  scale, 
  may 
  be 
  found 
  in 
  the 
  explo- 
  

   sive 
  eruption 
  of 
  Krakatau 
  on 
  the 
  27th 
  of 
  August 
  1883, 
  when 
  the 
  entire 
  

   northern 
  part 
  of 
  the 
  volcano, 
  about 
  9 
  square 
  miles 
  in 
  area, 
  and 
  compris- 
  

   ing 
  two-thirds 
  of 
  the 
  whole 
  island, 
  sank 
  and 
  disappeared 
  beneath 
  the 
  

   sea. 
  2 
  

  

  It 
  is 
  a 
  question 
  of 
  some 
  interest 
  what 
  the 
  original 
  height 
  of 
  the 
  volcano 
  

   Original 
  height 
  of 
  an- 
  was 
  before 
  the 
  blowing 
  away 
  of 
  the 
  upper 
  part, 
  

   cient 
  cone 
  * 
  Most 
  sections 
  of 
  the 
  inner 
  cone 
  present 
  an 
  angle 
  

  

  of 
  3£°, 
  but 
  the 
  average 
  slope 
  of 
  the 
  outer 
  cone 
  is 
  distinctly 
  lower, 
  not 
  

   exceeding 
  about 
  25° 
  ; 
  this 
  may 
  be 
  caused 
  in 
  part 
  by 
  a 
  central 
  subsidence 
  

   of 
  the 
  volcano, 
  due 
  to 
  the 
  weight 
  of 
  the 
  continually 
  increasing 
  mass 
  of 
  

   material, 
  a 
  kind 
  of 
  subsidence 
  which 
  has 
  been 
  recognised 
  in 
  the 
  case 
  of 
  

   other 
  volcanic 
  mountains 
  3 
  ; 
  but 
  I 
  am 
  inclined 
  to 
  think 
  that 
  it 
  is 
  mainly 
  

   due 
  to 
  the 
  flows 
  of 
  lava, 
  which 
  constitute 
  so 
  large 
  a 
  portion 
  of 
  the 
  

   material 
  of 
  the 
  outer 
  cone, 
  having 
  solidified 
  at 
  a 
  lower 
  average 
  angle 
  of 
  

   slope 
  than 
  that 
  adopted 
  by 
  the 
  fragmentary 
  ejecta 
  which 
  now 
  form 
  the 
  

  

  1 
  It 
  may 
  be 
  remarked, 
  incidentally, 
  that 
  the 
  dimensions 
  of 
  the 
  ancient 
  crater 
  of 
  Barren 
  

   Island 
  are 
  about 
  the 
  same 
  as 
  those 
  of 
  the 
  Vesuvian 
  crater 
  of 
  1822, 
  the 
  formation 
  of 
  which 
  

   during 
  a 
  paroxysmal 
  eruption 
  was 
  actually 
  witnessed 
  by 
  Scrope. 
  

  

  2 
  A 
  short 
  report 
  on 
  the 
  eruption 
  of 
  Krakatau 
  on 
  the 
  26th, 
  27th, 
  and 
  28th 
  of 
  August 
  1883 
  

   by 
  R. 
  D. 
  M. 
  Verbeek, 
  mining 
  engineer 
  ; 
  translated 
  from 
  the 
  original 
  Dutch 
  by 
  I. 
  I. 
  Kb'nigs 
  ; 
  

   Simla, 
  1884, 
  p. 
  4. 
  

  

  3 
  A 
  paper 
  on 
  the 
  subject, 
  by 
  my 
  father, 
  Mr. 
  R. 
  Mallet, 
  is 
  to 
  be 
  found 
  in 
  the 
  Quart, 
  

   Jour. 
  Geological 
  Society, 
  November 
  1877. 
  The 
  subsidence 
  in 
  question 
  is, 
  of 
  course, 
  of 
  a 
  dif- 
  

   ferent 
  kind 
  to 
  that 
  alluded 
  to 
  in 
  the 
  last 
  paragraph 
  with 
  reference 
  to 
  the 
  deficient 
  height 
  of 
  

   the 
  north-western 
  half 
  of 
  the 
  volcano. 
  

  

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  ) 
  

  

  