﻿CLIMATE 
  AND 
  MIGRATION 
  CURRY 
  433 
  

  

  degrees 
  (England, 
  northern 
  France 
  and 
  Germany). 
  After 
  400 
  A. 
  D. 
  

   no 
  clearly 
  defined 
  distinction 
  can 
  be 
  made. 
  Italy, 
  Spain, 
  France, 
  

   England 
  and 
  Germany 
  can 
  all 
  claim 
  to 
  have 
  been 
  pre-eminent 
  in 
  

   different 
  ways 
  at 
  different 
  times; 
  but 
  the 
  general 
  tendency 
  for 
  the 
  best 
  

   conditions 
  to 
  move 
  northwards 
  is 
  undeniable. 
  

  

  The 
  year 
  1840 
  should 
  have 
  marked 
  a 
  wave 
  crest 
  of 
  migration, 
  

   of 
  desiccation, 
  and 
  of 
  a 
  low 
  level 
  of 
  the 
  Caspian 
  Sea. 
  A 
  marked 
  drop 
  

   in 
  this 
  level 
  did 
  occur 
  about 
  1820, 
  but 
  it 
  was 
  evidently 
  not 
  connected 
  

   with 
  any 
  cause 
  sulFicient 
  to 
  bring 
  about 
  disaster 
  in 
  the 
  steppes 
  or 
  a 
  

   very 
  serious 
  economic 
  upheaval. 
  From 
  the 
  generally 
  "settled" 
  

   conditions 
  of 
  the 
  last 
  200 
  years 
  it 
  follows 
  that 
  either 
  the 
  primary 
  or 
  

   the 
  secondary 
  cause 
  of 
  desiccation, 
  or 
  both, 
  have 
  ceased 
  to 
  exercise 
  

   their 
  former 
  influence. 
  

  

  Following 
  Huntington's 
  conclusion 
  that 
  the 
  changes 
  which 
  now 
  

   appear 
  as 
  640-year 
  cycles 
  lie 
  midway 
  between 
  Bruckner's 
  and 
  the 
  

   glacial 
  cycles 
  in 
  intensity, 
  the 
  causes 
  of 
  change 
  referred 
  to 
  above 
  a? 
  

   primary 
  must 
  be 
  regarded 
  as 
  being 
  connected 
  with 
  the 
  last 
  glacial 
  

   cycle.* 
  

  

  The 
  geographical 
  and 
  historical 
  evidence 
  in 
  favor 
  of 
  the 
  existence 
  

   of'a 
  640-year 
  cycle 
  is 
  inconclusive 
  and 
  incomplete 
  in 
  the 
  absence 
  of 
  

   any 
  explanation 
  of 
  its 
  cause 
  or 
  causes. 
  The 
  alternating 
  periods 
  of 
  

   migration 
  and 
  consolidation 
  are, 
  however, 
  so 
  clearly 
  marked 
  that 
  their 
  

   existence 
  can 
  hardly 
  be 
  a 
  matter 
  of 
  controversy, 
  apart 
  from 
  the 
  

   question 
  of 
  periodicity. 
  The 
  connection 
  between 
  droughts 
  and 
  migra- 
  

   tions 
  has 
  been 
  recently 
  discussed 
  both 
  by 
  H. 
  Peake 
  and 
  C. 
  E. 
  P. 
  

   Brooks. 
  Their 
  work 
  shows 
  that 
  there 
  is 
  need 
  for 
  the 
  treatment 
  in 
  

   greater 
  detail 
  of 
  the 
  historical 
  evidence, 
  both 
  as 
  regards 
  the 
  migrations 
  

   of 
  the 
  steppe 
  peoples 
  and 
  deterioration 
  in 
  the 
  more 
  highly 
  organized 
  

   states. 
  

  

  The 
  fact 
  that 
  conditions 
  have 
  been 
  so 
  settled 
  for 
  nearly 
  600 
  years, 
  

   (since 
  the 
  migrations 
  of 
  the 
  Mongol 
  period), 
  has 
  led 
  to 
  these 
  questions 
  

   being 
  regarded 
  as 
  of 
  academic 
  or 
  even 
  merely 
  "bookish" 
  interest. 
  

   It 
  is, 
  however, 
  possible 
  that 
  changes 
  may 
  occur 
  again 
  on 
  a 
  scale 
  

   similar 
  to 
  those 
  which 
  destro3^ed 
  the 
  civilizations 
  of 
  the 
  past. 
  Some 
  

   such 
  change 
  as 
  that 
  which 
  brought 
  new 
  peoples 
  into 
  Italy, 
  Greece, 
  

   Asia 
  Minor, 
  Mesopotamia, 
  Persia, 
  and 
  India 
  between 
  1600 
  B. 
  C. 
  and 
  

   1300 
  B. 
  C. 
  might 
  again 
  take 
  place 
  suddenly 
  and 
  transform 
  the 
  world 
  

   in 
  the 
  life-time 
  of 
  our 
  own 
  or 
  the 
  next 
  generation. 
  Such 
  considera- 
  

   tions 
  indicate 
  that 
  these 
  questions, 
  being, 
  at 
  least, 
  of 
  potential 
  im- 
  

   portance 
  in 
  high 
  politics, 
  deserve 
  greater 
  attention 
  than 
  they 
  have 
  

  

  » 
  other 
  evidence 
  bearing 
  on 
  the 
  nature 
  of 
  these 
  primary 
  and 
  secondary 
  causes 
  of 
  change 
  is, 
  possibly, 
  to 
  be 
  

   found 
  in 
  such 
  facts 
  as 
  that 
  the 
  level 
  of 
  the 
  Caspian 
  was 
  much 
  lower 
  during 
  the 
  fifth 
  drought 
  than 
  it 
  is 
  now: 
  

   that 
  this 
  drought, 
  judging 
  by 
  the 
  historical 
  evidence, 
  appears 
  to 
  present 
  a 
  triple 
  wave 
  crest: 
  that 
  the 
  fourth 
  

   and 
  sixth 
  droughts 
  had 
  much 
  less 
  serious 
  effects 
  than 
  the 
  third 
  and 
  fifth: 
  and 
  that 
  the 
  eSects 
  of 
  the 
  later 
  

   droughts 
  were 
  comparatively 
  unimportant 
  in 
  Arabia. 
  

  

  