﻿250 
  Scientific 
  Intelligence. 
  

  

  States. 
  The 
  present 
  volume 
  raises 
  this 
  number 
  to 
  219 
  and 
  adds 
  

   42 
  stations 
  for 
  southern 
  Canada. 
  The 
  number 
  of 
  stations 
  is 
  thus 
  

   a 
  little 
  more 
  than 
  doubled. 
  The 
  principal 
  facts 
  for 
  73 
  stations 
  in 
  

   India 
  and 
  40 
  other 
  stations 
  are 
  added, 
  all 
  reduced 
  to 
  the 
  new 
  

   method 
  of 
  determining 
  the 
  gravity 
  anomalies. 
  This 
  large 
  amount 
  

   of 
  data 
  is 
  subjected 
  to 
  analysis 
  and 
  several 
  hypotheses 
  of 
  the 
  

   nature 
  of 
  isostasy 
  are 
  tested 
  by 
  it. 
  

  

  As 
  is 
  familiar 
  to 
  those 
  who 
  have 
  followed 
  the 
  previous 
  publi- 
  

   cations, 
  the 
  hypothesis 
  has 
  been 
  introduced 
  that 
  every 
  topo- 
  

   graphic 
  feature 
  is 
  balanced 
  by 
  a 
  corresponding 
  variation 
  in 
  

   density 
  in 
  a 
  column 
  reaching 
  to 
  a 
  uniform 
  level, 
  — 
  the 
  level 
  of 
  

   complete 
  isostatic 
  compensation. 
  Thus 
  every 
  unit 
  column 
  con- 
  

   tains 
  the 
  same 
  mass. 
  Furthermore, 
  the 
  compensation 
  is 
  assumed 
  

   to 
  be 
  uniformly 
  distributed 
  down 
  to 
  the 
  level 
  of 
  complete 
  com- 
  

   pensation, 
  but 
  there 
  to 
  abruptly 
  terminate. 
  The 
  data 
  of 
  geodesy 
  

   shows 
  that 
  such 
  a 
  hypothesis 
  of 
  perfect, 
  uniformly 
  distributed, 
  

   and 
  local 
  isostasy 
  is 
  much 
  nearer 
  the 
  truth 
  than 
  a 
  hypothesis 
  of 
  

   no 
  isostasy, 
  but 
  it 
  is 
  obvious 
  to 
  geologists 
  that 
  this 
  hypothesis 
  

   must 
  be 
  a 
  very 
  much 
  simplified 
  and 
  generalized 
  picture 
  of 
  the 
  

   truth. 
  The 
  new 
  gravity 
  stations 
  show, 
  as 
  seen 
  in 
  fig. 
  11, 
  a 
  

   greater 
  complexity 
  of 
  the 
  map 
  of 
  lines 
  of 
  equal 
  anomaly. 
  A 
  

   number 
  of 
  new 
  localities 
  of 
  high 
  anomaly 
  have 
  been 
  discovered, 
  

   and, 
  in 
  general, 
  where 
  the 
  stations 
  are 
  most 
  abundant 
  the 
  anomaly 
  

   gradients 
  are 
  steepest. 
  

  

  The 
  question 
  of 
  local 
  versus 
  regional 
  isostasy 
  is 
  important. 
  

   The 
  hypothesis 
  of 
  local 
  isostasy 
  satisfies 
  the 
  geodetic 
  data 
  about 
  

   as 
  well 
  as 
  that 
  of 
  regional 
  isostasy 
  up 
  to 
  some 
  radial 
  distance 
  

   between 
  59 
  and 
  167 
  kilometers 
  ; 
  but 
  the 
  geologic 
  evidence 
  favors 
  

   regional 
  isostasy 
  to 
  as 
  great 
  a 
  limit 
  as 
  is 
  compatible 
  with 
  the 
  

   geodetic 
  data 
  and 
  would 
  favor 
  a 
  wide 
  regional 
  distribution 
  for 
  a 
  

   part 
  of 
  it, 
  a 
  narrower 
  regional 
  distribution 
  for 
  another 
  part. 
  

  

  The 
  problem 
  of 
  the 
  depth 
  of 
  compensation 
  is 
  also 
  tried 
  out 
  by 
  

   a 
  number 
  of 
  solutions, 
  with 
  the 
  result 
  that 
  Bowie 
  states 
  the 
  best 
  

   mean 
  for 
  the 
  depth 
  of 
  the 
  level 
  of 
  complete 
  compensation 
  under 
  

   the 
  hypothesis 
  of 
  uniform 
  distribution 
  to 
  be 
  96 
  kilometers. 
  He 
  

   believes 
  that 
  future 
  values 
  derived 
  from 
  much 
  more 
  extensive 
  

   data 
  will 
  fall 
  between 
  80 
  and 
  130 
  kilometers. 
  J. 
  b. 
  

  

  2. 
  The 
  Prodromus 
  of 
  Nicolaus 
  Steno?s 
  Dissertation 
  Concerning 
  

   a 
  Solid 
  JBody 
  Enclosed 
  by 
  Process 
  of 
  Nature 
  Within 
  a 
  Solid. 
  

   An 
  English 
  version 
  with 
  an 
  introduction 
  and 
  explanatory 
  notes 
  

   by 
  John 
  Garrett 
  Winter, 
  University 
  of 
  Michigan 
  ; 
  with 
  a 
  

   foreword 
  by 
  William 
  H. 
  Hobbs, 
  University 
  of 
  Michigan. 
  Pp. 
  

   v, 
  124, 
  plsl 
  vii. 
  Macmillan, 
  1916. 
  This 
  is 
  Part 
  II, 
  Vol. 
  XL 
  

   Humanistic 
  Series, 
  University 
  of 
  31ichigan 
  Studies, 
  and 
  is 
  one 
  of 
  

   the 
  "contributions 
  to 
  the 
  history 
  of 
  Science." 
  — 
  Kicolaus 
  Steno 
  

   w 
  T 
  as 
  born 
  in 
  Copenhagen, 
  Jan. 
  10, 
  1638 
  and 
  belongs 
  thus 
  to 
  the 
  

   generation 
  which 
  began 
  to 
  lay 
  the 
  foundations 
  of 
  modern 
  science. 
  

   In 
  1665 
  he 
  was 
  in 
  Florence 
  and 
  in 
  1669 
  the 
  Prodromus 
  was 
  

   published. 
  It 
  was 
  to 
  be 
  the 
  introduction 
  to 
  a 
  larger 
  work 
  which 
  

   was 
  however 
  never 
  written. 
  The 
  work 
  is 
  remarkable 
  in 
  its 
  

  

  