﻿478 
  F. 
  A. 
  Perret 
  — 
  Volcanic 
  Research 
  at 
  Kilauea. 
  

  

  The 
  western 
  anchorage 
  was 
  the 
  projecting 
  tongue 
  of 
  an 
  old 
  

   lava 
  flow 
  around 
  which 
  the 
  cable 
  was 
  bent 
  and 
  secured 
  with 
  

   clips, 
  while 
  at 
  the 
  eastern 
  end 
  logs 
  were 
  buried 
  crosswise 
  in 
  a 
  

   cleft 
  of 
  the 
  lava 
  rock. 
  

  

  A 
  team 
  of 
  horses, 
  with 
  appropriate 
  tackle, 
  was 
  employed 
  

   for 
  the 
  final 
  stretching 
  of 
  the 
  cable 
  to 
  a 
  5 
  per 
  cent 
  drop. 
  

  

  The 
  trolley, 
  shown 
  in 
  fig. 
  2, 
  ran 
  on 
  this 
  main 
  cable 
  and 
  could 
  

   be 
  brought 
  to 
  any 
  desired 
  position 
  above 
  the 
  lake 
  by 
  means 
  of 
  

   two 
  smaller 
  guy 
  cables, 
  pulling 
  in 
  either 
  direction 
  by 
  winches, 
  

   as 
  shown. 
  An 
  insulated 
  electric 
  cable, 
  running 
  over 
  the 
  lower 
  

   wheels 
  of 
  the 
  trolley 
  and, 
  also, 
  under 
  the 
  control 
  of 
  a 
  winch, 
  

   served 
  to 
  lower 
  the 
  instruments 
  into 
  the 
  lake 
  and 
  to 
  maintain 
  

   the 
  electrical 
  connection 
  with 
  the 
  indicating 
  apparatus 
  " 
  on 
  

   shore." 
  It 
  was 
  found 
  necessary 
  to 
  support 
  the 
  horizontal 
  por- 
  

   tion 
  of 
  this 
  cable 
  at 
  intervals 
  by 
  small 
  pulleys 
  running 
  on 
  the 
  

   main 
  cable 
  in 
  order 
  that 
  its 
  weight 
  should 
  not 
  prevent 
  the 
  

   lowering 
  of 
  the 
  instrument 
  — 
  an 
  arrangement 
  w 
  T 
  hich 
  could 
  not 
  

   well 
  be 
  shown 
  on 
  the 
  diagram. 
  

  

  All 
  was 
  thus 
  ready, 
  but 
  an 
  incident, 
  occurring 
  at 
  this 
  stage 
  

   of 
  the 
  proceedings, 
  has 
  so 
  important 
  a 
  bearing 
  upon 
  the 
  subse- 
  

   quent 
  experiments 
  that 
  it 
  may 
  well 
  be 
  related 
  here. 
  A 
  kink 
  

   in 
  one 
  of 
  the 
  smaller 
  cables 
  caused 
  it 
  to 
  break 
  and 
  fall 
  into 
  the 
  

   lake, 
  where 
  it 
  was 
  quickly 
  fused. 
  Now, 
  the 
  temperature 
  of 
  

   the 
  Kilauean 
  lava 
  has 
  been 
  quite 
  generally 
  considered 
  to 
  be 
  at 
  

   least 
  equal 
  to 
  the 
  fusing 
  point 
  of 
  wrought 
  iron, 
  for 
  the 
  reason 
  

   that 
  rods 
  or 
  wires 
  of 
  that 
  metal, 
  immersed 
  in 
  the 
  lava, 
  were 
  

   rapidly 
  fused. 
  The 
  lava 
  melted 
  the 
  iron 
  — 
  ergo, 
  it 
  had 
  the 
  heat 
  

   to 
  do 
  it 
  — 
  no 
  deduction 
  could 
  be 
  more 
  simple, 
  more 
  direct, 
  nor 
  

   more 
  convincing. 
  And 
  yet, 
  to 
  a 
  practised 
  eye, 
  the 
  degree 
  of 
  

   incandescence 
  — 
  even 
  in 
  the 
  fountains 
  and 
  in 
  spatter-grottoes 
  

   where 
  the 
  lava 
  was 
  protected 
  from 
  radiation 
  — 
  indicated 
  a 
  much 
  

   lower 
  temperature. 
  The 
  fusing 
  of 
  the 
  steel 
  cable 
  would 
  mean, 
  

   let 
  us 
  say, 
  1300° 
  C, 
  but 
  it 
  was 
  impossible 
  to 
  admit 
  such 
  a 
  de- 
  

   gree 
  of 
  heat. 
  How, 
  then, 
  explain 
  the 
  fusion 
  of 
  the 
  steel? 
  

  

  The 
  first 
  glance 
  at 
  the 
  fused 
  cable-end 
  showed 
  the 
  metal 
  to 
  

   have 
  been 
  converted 
  into 
  the 
  sulphide, 
  and 
  it 
  was 
  realized 
  that, 
  

   not 
  thermal 
  action 
  alone, 
  but 
  chemical 
  activity, 
  as 
  well, 
  was 
  

   here 
  involved. 
  The 
  presence 
  of 
  sulphur 
  — 
  revealed 
  by 
  the 
  

   abundant 
  evolution 
  of 
  S0 
  2 
  — 
  had 
  not 
  been 
  considered 
  in 
  plan- 
  

   ning 
  the 
  experiments, 
  and 
  this 
  incident 
  of 
  the 
  fused 
  cable 
  

   boded 
  ill 
  for 
  the 
  instruments 
  destined 
  for 
  immersion 
  in 
  the 
  

   lake. 
  

  

  But 
  another, 
  and 
  broader, 
  consequence 
  results 
  from 
  this 
  

   demonstration 
  of 
  chemical 
  activity, 
  viz., 
  that 
  all 
  estimates 
  of 
  

   the 
  temperature 
  of 
  liquid 
  lavas 
  based 
  upon 
  the 
  melting 
  therein 
  

   of 
  wires 
  or 
  strips 
  of 
  various 
  metals 
  whose 
  fusion 
  points 
  were 
  

   known, 
  must 
  be 
  considered 
  as 
  having 
  practically 
  no 
  value. 
  As 
  

  

  