﻿JOURNAL 
  

  

  OF 
  THE 
  

  

  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  

  

  Vol. 
  12 
  . 
  September 
  19, 
  1922 
  No. 
  15 
  

  

  GEOPHYSICS. 
  — 
  A 
  plea 
  for 
  geophysical 
  and 
  geochemical 
  observatories.^ 
  

   T. 
  A. 
  Jaggar, 
  Hawaiian 
  Volcano 
  Observatory. 
  

  

  A 
  volcanic 
  system, 
  is 
  known 
  to 
  the 
  volcanologist 
  as 
  a 
  place, 
  not 
  

   merely 
  of 
  kinds 
  of 
  processes, 
  but 
  of 
  measurable 
  events. 
  In 
  the 
  course 
  

   of 
  events 
  processes 
  change. 
  Nowhere 
  is 
  this 
  so 
  true 
  as 
  in 
  a 
  physico- 
  

   chemical 
  system 
  dependent 
  on 
  pressure, 
  temperature 
  and 
  saturation. 
  

   The 
  volcano 
  edifice 
  is 
  a 
  furnace 
  changing 
  these 
  things 
  in 
  accordance 
  

   with 
  fixed 
  laws 
  of 
  accumulation, 
  of 
  movement 
  of 
  the 
  crust 
  of 
  the 
  Earth, 
  

   and 
  of 
  reaction 
  with 
  the 
  watery 
  and 
  atmospheric 
  envelopes 
  that 
  en- 
  

   case 
  the 
  crust. 
  The 
  relation 
  of 
  the 
  volcano 
  and 
  its 
  processes 
  to 
  these 
  

   changing 
  features 
  of 
  the 
  globe 
  through 
  the 
  seasons 
  and 
  the 
  years, 
  

   incessantly 
  measured, 
  is 
  the 
  most 
  fundamental 
  control 
  for 
  all 
  the 
  

   processes. 
  Therefore 
  the 
  sending 
  of 
  geological 
  expeditions 
  concerned 
  

   only 
  with 
  a 
  process 
  here, 
  and 
  a 
  process 
  there, 
  will 
  no 
  more 
  solve 
  the 
  

   volcano 
  mystery 
  than 
  the 
  sending 
  of 
  an 
  expedition 
  to 
  Mauritius 
  to 
  

   observe 
  an 
  eclipse 
  will 
  resolve 
  the 
  orbits 
  of 
  the 
  solar 
  system. 
  Let 
  

   the 
  astronomers 
  say 
  which 
  is 
  the 
  more 
  important, 
  an 
  expedition 
  or 
  

   an 
  observatory. 
  The 
  expedition 
  may 
  furnish 
  vitally 
  important 
  

   methods 
  and 
  data. 
  Only 
  the 
  cooperation 
  of 
  fixed 
  stations 
  can 
  collect 
  

   these 
  into 
  a 
  constructive 
  science. 
  

  

  The 
  comparison 
  of 
  geology 
  with 
  astronomy 
  may 
  be 
  profitable 
  to 
  

   geology 
  from 
  another 
  angle 
  ; 
  namely, 
  the 
  application 
  to 
  the 
  science 
  

   of 
  special 
  invention 
  and 
  expensive 
  apparatus. 
  Astronomy 
  and 
  geology 
  

   both 
  deal 
  with 
  enormous 
  bulks, 
  gradual 
  migrations, 
  physical 
  processes, 
  

   chemical 
  reactions, 
  hidden 
  masses 
  revealable 
  only 
  by 
  the 
  aid 
  of 
  in- 
  

   struments 
  of 
  precision. 
  From 
  the 
  time 
  of 
  Lyell 
  geology 
  has 
  been 
  

   increasingly 
  dependent 
  on 
  the 
  study 
  of 
  the 
  living 
  Earth 
  to 
  interpret 
  

   the 
  past. 
  The 
  life 
  of 
  the 
  Earth's 
  interior 
  and 
  of 
  its 
  outer 
  shells, 
  

   through 
  the 
  time 
  of 
  the 
  present 
  generations 
  of 
  men, 
  is 
  just 
  beginning 
  

   to 
  be 
  studied. 
  With 
  due 
  allowance 
  for 
  the 
  contributions 
  of 
  terres- 
  

   trial 
  gravity, 
  geodesy, 
  magnetism, 
  and 
  seismology, 
  all 
  of 
  recent 
  date, 
  

  

  1 
  Received 
  November 
  21, 
  1921. 
  

  

  343 
  

  

  