﻿316 
  T. 
  C. 
  CliamberMn 
  — 
  Mathematics 
  of 
  Isostasy. 
  

  

  all 
  the 
  solutions 
  previously 
  offered 
  except 
  the 
  true 
  one,, 
  

   which 
  of 
  course 
  would 
  still 
  stand, 
  but 
  that 
  it 
  would 
  be 
  

   possible 
  for 
  the 
  mathematician 
  to 
  present 
  new 
  solutions 
  

   that 
  would 
  fit 
  the 
  new 
  data 
  as 
  well 
  as 
  the 
  old. 
  And 
  this 
  

   might 
  be 
  repeated 
  until 
  a 
  moral 
  conviction 
  would 
  be 
  

   established 
  that 
  the 
  one 
  solution 
  that 
  held 
  good 
  through 
  

   all 
  additions 
  of 
  data 
  was 
  the 
  true 
  one, 
  but 
  such 
  moral 
  

   conviction 
  would 
  be 
  as 
  near 
  to 
  a 
  strictly 
  mathematical 
  

   proof 
  as 
  it 
  would 
  be 
  possible 
  to 
  attain. 
  

  

  Some 
  time 
  after 
  this 
  memorable 
  discussion, 
  on 
  due 
  

   deliberation 
  it 
  seemed 
  best 
  to 
  give 
  to 
  a 
  wider 
  audience 
  

   the 
  benefit 
  of 
  MacMillan's 
  studies 
  on 
  the 
  mathematical 
  

   aspects 
  of 
  the 
  isostatic 
  inquiry, 
  and 
  so 
  a 
  summary 
  was 
  

   published 
  in 
  the 
  Journal 
  of 
  Geology. 
  6 
  There 
  was 
  no 
  

   thought 
  that 
  it 
  had 
  any 
  special 
  bearing 
  on 
  any 
  particular 
  

   discussion 
  of 
  isostasy, 
  except 
  that 
  of 
  course 
  it 
  related 
  

   to 
  the 
  fundamental 
  work 
  of 
  Hayf 
  ord, 
  and 
  was 
  a 
  tribute 
  

   to 
  its 
  monumental 
  character. 
  My 
  thought 
  was 
  that 
  Mac- 
  

   Millan's 
  studies 
  were 
  a 
  contribution 
  to 
  sound 
  methods 
  

   and 
  wholesome 
  interpretations 
  rather 
  than 
  .an 
  adverse 
  

   criticism 
  of 
  the 
  work 
  which 
  any 
  of 
  the 
  great 
  students 
  of 
  

   the 
  subject 
  had 
  done. 
  In 
  the 
  main 
  his 
  discriminations 
  

   related 
  to 
  necessary 
  and 
  altogether 
  unavoidable 
  limita- 
  

   tions, 
  a 
  knowledge 
  of 
  which 
  it 
  is 
  wholesome 
  for 
  everyone 
  

   to 
  possess. 
  I 
  still 
  think 
  they 
  are 
  wholesome, 
  and 
  I 
  rec- 
  

   ommend 
  that 
  they 
  be 
  re-read 
  and 
  kept 
  in 
  mind. 
  

  

  For 
  myself, 
  I 
  believe 
  the 
  subject 
  of 
  isostasy 
  has 
  an 
  

   importance 
  to 
  geology 
  that 
  none 
  of 
  us 
  have 
  yet 
  come 
  ade- 
  

   quately 
  to 
  realize; 
  but 
  isostasy 
  can 
  only 
  come 
  into 
  its 
  

   place 
  of 
  real 
  importance 
  — 
  which 
  of 
  course 
  is 
  precisely 
  

   its 
  true 
  place 
  — 
  through 
  critical 
  scrutiny 
  of 
  every 
  aspect 
  

   of 
  the 
  subject 
  and 
  by 
  circumspection 
  in 
  basing 
  interpre- 
  

   tations 
  on 
  it. 
  The 
  more 
  appreciative 
  and 
  friendly 
  our 
  

   attitude, 
  the 
  more 
  searching 
  the 
  scrutiny 
  of 
  its 
  processes 
  

   may 
  well 
  be 
  made, 
  and 
  the 
  more 
  circumspect 
  the 
  inter- 
  

   pretations 
  based 
  on 
  the 
  results. 
  

  

  I 
  have 
  recited 
  this 
  little 
  history 
  as 
  the 
  best 
  way 
  of 
  dis- 
  

   missing 
  the 
  impression 
  which 
  Dr. 
  Barrell 
  seems 
  unfor- 
  

   tunately 
  to 
  have 
  entertained, 
  that 
  MacMillan's 
  paper 
  

   sprang 
  from 
  hasty 
  consideration, 
  or 
  shallow 
  work, 
  or 
  

   was 
  given 
  to 
  print 
  as 
  a 
  disturbing 
  challenge 
  of 
  the 
  work 
  

   of 
  any 
  of 
  those 
  who 
  were 
  diligently 
  studying 
  the 
  problem 
  

   from 
  their 
  own 
  points 
  of 
  view. 
  

  

  I 
  may 
  perhaps 
  be 
  permitted 
  to 
  add 
  here 
  that 
  at 
  the 
  

  

  6 
  Jour, 
  of 
  Geol., 
  Feb.-Mar., 
  pp. 
  105-111, 
  1917. 
  

  

  