﻿314 
  T. 
  C. 
  Chamberlin 
  — 
  Mathematics 
  of 
  Isostasy. 
  

  

  At 
  different 
  times 
  and 
  independently, 
  Dr. 
  F. 
  R. 
  Moulton, 
  

   Di\ 
  A. 
  C. 
  Lnnn 
  and 
  Dr. 
  Wm. 
  D. 
  MacMillan 
  were 
  good 
  

   enough 
  to 
  inspect 
  the 
  published 
  treatment 
  and 
  to 
  assure 
  

   me 
  they 
  could 
  see 
  nothing- 
  in 
  it 
  that 
  favored 
  the 
  result 
  

   76 
  miles 
  as 
  against 
  the 
  result 
  178 
  miles. 
  . 
  

  

  These 
  recurring 
  inspections 
  were 
  scattered 
  through 
  

   several 
  years 
  and 
  had 
  naturally 
  awakened 
  certain 
  other 
  

   questions 
  as 
  to 
  the 
  specific 
  trustworthiness 
  of 
  the 
  mathe- 
  

   matical* 
  methods 
  adopted 
  in 
  handling 
  the 
  geodetic 
  data. 
  

   And 
  so 
  at 
  length 
  I 
  ventured 
  to 
  ask 
  Dr. 
  MacMillan 
  to 
  

   make 
  a. 
  study 
  of 
  them 
  purely 
  from 
  the 
  mathematical 
  

   point 
  of 
  view. 
  This 
  Dr. 
  MacMillan 
  was 
  good 
  enough 
  to 
  

   do. 
  There 
  was 
  placed 
  at 
  his 
  command 
  the 
  whole 
  history 
  

   of 
  the 
  inquiry 
  and 
  its 
  literature, 
  as 
  well 
  as 
  such 
  sugges- 
  

   tions 
  as 
  several 
  of 
  us 
  who 
  had 
  been 
  interested 
  in 
  the 
  sub- 
  

   ject 
  for 
  years 
  could 
  give. 
  At 
  the 
  close 
  of 
  his 
  study 
  he 
  

   prepared 
  an 
  abstract 
  of 
  his 
  results. 
  This 
  was 
  discussed 
  

   freely 
  by 
  various 
  associates 
  interested 
  in 
  the 
  matter, 
  

   mathematicians, 
  astronomers, 
  physicists, 
  and 
  geologists. 
  

   As 
  a 
  result 
  it 
  came 
  to 
  be 
  our 
  common 
  judgment 
  that 
  Mac- 
  

   Millan 
  's 
  critique 
  should 
  be 
  laid 
  before 
  Hayford 
  in 
  a 
  

   friendly, 
  informal 
  way, 
  and 
  that 
  later 
  perhaps 
  we 
  should 
  

   invite 
  him 
  to 
  unite 
  with 
  us 
  in 
  a 
  quiet 
  discussion 
  of 
  the 
  

   matter. 
  The 
  result 
  was 
  that 
  after 
  such 
  submission 
  and 
  

   some 
  correspondence, 
  a 
  conference 
  was 
  arranged. 
  Dr. 
  

   Hayford 
  came 
  over 
  to 
  the 
  Quadrangle 
  Club 
  and 
  lunched 
  

   with 
  us, 
  after 
  which 
  we 
  adjourned 
  to 
  my 
  lecture 
  room 
  

   and 
  spent 
  the 
  afternoon 
  in 
  an 
  ideally 
  frank 
  and 
  friendly 
  

   discussion. 
  It 
  so 
  happened 
  that 
  President 
  "Woodward, 
  

   of 
  the 
  Carnegie 
  Institution, 
  on 
  his 
  way 
  to 
  Mt. 
  Wilson, 
  

   lunched 
  with 
  us 
  and 
  joined 
  in 
  the 
  discussion. 
  There 
  

   were 
  present 
  mathematicians, 
  astronomers, 
  physicists, 
  

   and 
  geologists 
  to 
  the 
  number 
  of 
  a 
  dozen 
  or 
  more. 
  Be- 
  

   sides 
  Hayford 
  and 
  MacMillan 
  there 
  were 
  present 
  Moore 
  

   and 
  some 
  of 
  his 
  colleagues 
  of 
  the 
  Mathematical 
  Depart- 
  

   ment, 
  Michelson 
  and 
  some 
  of 
  his 
  colleagues 
  of 
  the 
  

   Physical 
  Department, 
  Moulton 
  of 
  the 
  Division 
  of 
  Mathe- 
  

   matical 
  Astronomy, 
  and 
  those* 
  of 
  our 
  geological 
  staff 
  

   interested 
  in 
  the 
  problem. 
  

  

  The 
  conference 
  opened 
  with 
  an 
  elaborate 
  statement 
  by 
  

   MacMillan 
  supported 
  by 
  ample 
  citations 
  from 
  Hayford 
  's 
  

   printed 
  reports 
  to 
  show 
  the 
  care 
  and 
  caution 
  with 
  which 
  

   he 
  had 
  avoided 
  untenable 
  claims. 
  Hayford 
  replied 
  

   elaborately, 
  ably 
  setting 
  forth 
  his 
  methods 
  and 
  results 
  

   and 
  his 
  points 
  of 
  view. 
  The 
  subject 
  was 
  then 
  thrown 
  

  

  