﻿F. 
  A. 
  Ferret 
  — 
  Some 
  Kilauean 
  Formations. 
  159 
  

  

  was 
  not 
  a 
  matter 
  of 
  a 
  very 
  few 
  seconds 
  but 
  of 
  many 
  minutes. 
  

  

  as 
  indeed 
  we 
  should 
  infer, 
  considering 
  the 
  backing 
  of 
  a 
  mass 
  

   of 
  liquid 
  at 
  full 
  heat. 
  The 
  result, 
  then, 
  is 
  a 
  shell 
  of 
  crystal- 
  

   line 
  rock, 
  deposited 
  molecule 
  by 
  molecule 
  after 
  the 
  manner 
  of 
  

   an 
  electrotype, 
  and 
  whose 
  fusion 
  point 
  is 
  higher 
  than 
  the 
  tem- 
  

   perature 
  of 
  the 
  liquid 
  from 
  ivhich 
  it 
  consolidated. 
  We 
  may 
  

   believe, 
  therefore, 
  that 
  there 
  is 
  no 
  power 
  in 
  the 
  flow 
  to 
  re-fuse 
  

   the 
  crystalline 
  shell 
  deposited 
  therefrom 
  as 
  the 
  lava 
  — 
  especially 
  

   in 
  the 
  case 
  of 
  a 
  stream 
  — 
  will 
  not 
  possess 
  a 
  sufh'cient 
  degree 
  of 
  

   superheat 
  to 
  accomplish 
  this 
  ; 
  the 
  shell, 
  instead, 
  will 
  progres- 
  

   sively 
  increase 
  in 
  thickness. 
  

  

  The 
  writer 
  believes 
  that 
  failure 
  to 
  appreciate 
  this 
  most 
  

   important 
  fact, 
  viz., 
  that 
  the 
  fusion 
  point 
  of 
  the 
  crystalline 
  

   rock 
  is 
  above 
  the 
  temperature 
  at 
  which 
  the 
  original 
  lava 
  will 
  

   remain 
  fluid, 
  has 
  frequently 
  resulted 
  in 
  an 
  exaggerated 
  evalua- 
  

   tion 
  of 
  the 
  temperature 
  of 
  liquid 
  lava 
  through 
  the 
  practise 
  of 
  

   taking 
  the 
  melting 
  point 
  of 
  the 
  consolidated 
  crystalline 
  product 
  

   as 
  marking 
  the 
  lower 
  limit 
  of 
  the 
  liquid 
  lava's 
  temperature. 
  

   The 
  Halemaumau 
  lake, 
  for 
  example, 
  is 
  liquid 
  and 
  active 
  at 
  

   1050° 
  C.j 
  but 
  the 
  rock 
  of 
  its 
  consolidation 
  — 
  according 
  to 
  

   recent 
  tests 
  by 
  Dr. 
  E. 
  S. 
  Shepherd— 
  melts 
  at 
  1150° 
  C. 
  

  

  It 
  is 
  the 
  principle 
  — 
  truly 
  universal 
  in 
  its 
  distribution 
  — 
  of 
  

   relaxation 
  resulting 
  in 
  products 
  which 
  are 
  then 
  with 
  difficulty 
  

   removable. 
  In 
  the 
  field 
  of 
  volcanism 
  it 
  is 
  this 
  which 
  gives 
  to 
  

   the 
  crater 
  ledges 
  their 
  stability, 
  to 
  the 
  floating 
  island 
  its 
  span 
  

   of 
  existence, 
  and 
  which 
  for 
  a 
  time 
  ensures 
  the 
  growth 
  and 
  

   preservation 
  — 
  as 
  it 
  must 
  eventually 
  set 
  the 
  seal 
  of 
  closure 
  and 
  

   extinction 
  — 
  of 
  and 
  to 
  no 
  less 
  a 
  formation 
  than 
  the 
  volcanic 
  

   edifice 
  itself. 
  

  

  Posillipo. 
  Naples, 
  May 
  6, 
  1913. 
  

  

  