﻿J. 
  F. 
  CAMPBELL 
  ON 
  POLAR 
  GLACIATION 
  ETC. 
  475 
  

  

  times 
  without 
  breaking 
  much. 
  If 
  glacial 
  periods, 
  due 
  to 
  astronomical 
  

   or 
  other 
  causes, 
  have 
  in 
  fact 
  increased 
  evaporation 
  and 
  condensation, 
  

   ice-flows, 
  and 
  rivers 
  to 
  any 
  given 
  extent, 
  then 
  polar 
  currents 
  must 
  

   have 
  gained 
  power 
  during 
  these 
  periods, 
  because 
  movements 
  in 
  air 
  

   and 
  ocean 
  result 
  from 
  unequal 
  local 
  temperatures, 
  on 
  which 
  also 
  

   depend 
  the 
  local 
  growth 
  of 
  ice 
  on 
  land. 
  

  

  Problem,. 
  — 
  Are 
  the 
  clear 
  traces 
  of 
  ancient 
  glaciation 
  which 
  

   abound 
  caused 
  directly 
  and 
  indirectly 
  by 
  polar 
  currents 
  like 
  those 
  

   which 
  exist 
  and 
  modify 
  climate, 
  and 
  which 
  must 
  have 
  existed 
  ever 
  

   since 
  there 
  was 
  an 
  ocean 
  to 
  circulate 
  upon 
  a 
  revolving 
  round 
  world 
  

   warmed 
  by 
  the 
  sun 
  ? 
  Or, 
  secondly, 
  are 
  these 
  marks 
  made 
  by 
  polar 
  

   ice-flows 
  which 
  do 
  not 
  exist, 
  whose 
  existence 
  has 
  been 
  inferred 
  from 
  

   these 
  marks 
  ? 
  

  

  I 
  have 
  contributed 
  my 
  store 
  of 
  facts. 
  Those 
  Members 
  of 
  the 
  

   Society 
  who 
  care 
  for 
  this 
  inquiry 
  can 
  form 
  opinions 
  upon 
  all 
  the 
  

   facts 
  known 
  to 
  them. 
  If 
  all 
  the 
  knowledge 
  of 
  the 
  Society 
  could 
  be 
  

   brought 
  to 
  bear 
  on 
  a 
  point 
  by 
  a 
  debate 
  and 
  a 
  vote, 
  we 
  might 
  advance 
  

   geology 
  by 
  expressing 
  a 
  joint 
  opinion 
  upon 
  the 
  nature 
  and 
  extent 
  of 
  

   that 
  ancient 
  polar 
  glaciation 
  which 
  is 
  abundantly 
  proved 
  by 
  acknow- 
  

   ledged 
  facts. 
  

  

  Postscript 
  dated 
  Salt 
  Lake 
  City, 
  August 
  12, 
  1874. 
  

  

  I 
  have 
  now 
  crossed 
  the 
  glacial 
  current 
  of 
  the 
  Atlantic 
  and 
  the 
  

   Rocky 
  Mountains, 
  and 
  I 
  have 
  skirted 
  the 
  back 
  of 
  this 
  range 
  south- 
  

   wards 
  on 
  the 
  eastern 
  side 
  for 
  200 
  miles, 
  seeking 
  for 
  Mississipi 
  mo- 
  

   raines. 
  As 
  in 
  Europe, 
  so 
  in 
  America, 
  I 
  have 
  found 
  scratched 
  rocks 
  

   and 
  northern 
  drift 
  carried 
  far 
  south, 
  but 
  on 
  certain 
  meridians 
  only; 
  

   I 
  have 
  found 
  ancient 
  sea-margins, 
  or 
  something 
  very 
  like 
  them, 
  on 
  

   both 
  sides 
  of 
  the 
  Eocky 
  Mountains 
  and 
  at 
  corresponding 
  levels. 
  

   I 
  have 
  seen 
  ancient 
  lake- 
  margins 
  corresponding 
  to 
  the 
  wearing 
  

   done 
  by 
  the 
  rivers 
  which 
  flow 
  out 
  of 
  the 
  lakes. 
  I 
  have 
  seen 
  lakes 
  

   drained 
  and 
  lakes 
  filled 
  up, 
  and 
  all 
  known 
  signs 
  of 
  atmospheric 
  

   action 
  in 
  great 
  abundance 
  and 
  on 
  a 
  large 
  scale. 
  

  

  This 
  salt 
  lake 
  is 
  the 
  equivalent 
  of 
  the 
  Caspian, 
  in 
  latitude 
  and 
  in 
  

   lack 
  of 
  outlet. 
  As 
  at 
  the 
  Caspian, 
  so 
  here, 
  the 
  mountains 
  are 
  water- 
  

   worn 
  and 
  burrowed 
  by 
  " 
  canons," 
  but 
  a 
  conspicuous 
  old-level 
  

   water-line 
  is 
  on 
  the 
  hills 
  at 
  a 
  level 
  which 
  would 
  give 
  the 
  lake 
  an 
  

   outlet. 
  Lakes 
  through 
  which 
  waters 
  flood 
  into 
  this 
  salt 
  lake 
  are 
  

   sweet 
  like 
  the 
  mountain-streams. 
  The 
  rocks 
  about 
  it 
  are 
  freestone 
  

   and 
  coal 
  formation, 
  &c. 
  The 
  people 
  here 
  suppose 
  that 
  this 
  salt 
  lake 
  

   is 
  sea- 
  water 
  at 
  4340 
  feet 
  above 
  the 
  sea, 
  and 
  a 
  mark 
  of 
  the 
  elevation 
  

   of 
  the 
  whole 
  country. 
  I 
  attribute 
  the 
  spread 
  of 
  northern 
  drift 
  on 
  

   American 
  and 
  on 
  Eussian 
  plains 
  to 
  ancient 
  arctic 
  currents. 
  

  

  There 
  is 
  nothing 
  to 
  indicate 
  any 
  glacial 
  action 
  at 
  all 
  between 
  

   Chicago 
  and 
  Salt 
  Lake. 
  In 
  rising 
  from 
  726 
  feet 
  above 
  the 
  sea 
  to 
  

   8242 
  feet 
  (the 
  highest 
  point 
  on 
  the 
  railroad), 
  and 
  in 
  descending 
  to 
  

   4340 
  feet, 
  I 
  could 
  see 
  no 
  single 
  mark 
  of 
  ice-action 
  in 
  the 
  region. 
  

   For 
  164° 
  of 
  longitude, 
  about 
  lat. 
  40° 
  N, 
  from 
  the 
  Volga 
  to 
  this 
  place, 
  

   I 
  have 
  found 
  nothing 
  to 
  support 
  the 
  idea 
  that 
  solid 
  ice 
  extended 
  

  

  2l2 
  

  

  