﻿ACADEMY 
  OF 
  SCIENCES. 
  95 
  

  

  Among 
  the 
  Aleutian 
  Islands 
  or 
  along 
  the 
  Peninsula 
  of 
  Alaska, 
  I 
  saw 
  no 
  ter- 
  

   race 
  formations 
  such 
  as 
  I 
  have 
  before 
  described, 
  and 
  I 
  fail 
  to 
  find 
  amongst 
  the 
  

   navigators, 
  up 
  to 
  1855, 
  views 
  that 
  indicate 
  such 
  features. 
  To 
  the 
  far 
  north, 
  in 
  

   the 
  Behring 
  Strait, 
  the 
  English 
  views 
  represent 
  the 
  rocky 
  Diomede 
  Islands 
  as 
  

   bold, 
  high 
  and 
  flat-topped, 
  as 
  well 
  as 
  the 
  east 
  cape 
  of 
  Asia. 
  

   . 
  In 
  all 
  these 
  instances, 
  and 
  in 
  others 
  not 
  enumerated, 
  we 
  And 
  a 
  prevailing 
  

   feature, 
  regardless 
  of 
  the 
  dip 
  or 
  direction 
  of 
  the 
  stratification 
  of 
  the 
  rocks. 
  A 
  

   nearly 
  level 
  surface 
  of 
  rock 
  with 
  a 
  comparatively 
  thin 
  layer 
  of 
  soil 
  thereon 
  ; 
  the 
  

   plateaus 
  sometimes 
  miles 
  in 
  extent, 
  bordering 
  the 
  coast 
  line 
  with 
  jagged 
  cliffs, 
  

   which 
  illustrate 
  the 
  action 
  of 
  water 
  and 
  weather. 
  Above 
  these 
  plateaus 
  are 
  

   frequently 
  others 
  stretching 
  inshore, 
  and 
  reaching 
  elevations 
  of 
  certainly 
  1,200 
  

   feet, 
  and 
  probably 
  more. 
  

  

  Whilst 
  the 
  general 
  plateau 
  is 
  level, 
  or 
  nearly 
  so, 
  there 
  are 
  numerous 
  indica- 
  

   tions 
  that 
  broad 
  groovings 
  have 
  been 
  made 
  across 
  them, 
  as 
  exliibited 
  in 
  the 
  

   views 
  of 
  Points 
  Dume, 
  Concepcion 
  and 
  Orford, 
  and 
  across 
  the 
  ridge 
  of 
  Anacapa 
  

   Island. 
  And 
  it 
  is 
  noticeable 
  that 
  these 
  ploughings 
  or 
  groovings 
  are 
  across 
  the 
  

   points 
  and 
  across 
  the 
  islands, 
  and 
  run 
  with 
  the 
  general 
  trend 
  of 
  the 
  Coast 
  line. 
  

  

  These 
  prominent 
  features 
  are 
  sufficient 
  to 
  satisfy 
  us 
  that 
  more 
  effective 
  and 
  

   more 
  regular 
  agencies 
  were 
  at 
  work 
  to 
  form 
  them 
  than 
  are 
  at 
  work" 
  on 
  such 
  a 
  

   vast 
  scale 
  to-day. 
  

  

  The 
  upheaval 
  of 
  the 
  continental 
  shores 
  by 
  subterranean 
  action 
  can 
  not 
  pro- 
  

   duce 
  such 
  terraces 
  and 
  plateaus 
  ; 
  if 
  the 
  shores 
  of 
  the 
  Pacific 
  were 
  to-day 
  to 
  be 
  

   raised, 
  say 
  200 
  feet, 
  we 
  know 
  from 
  the 
  depths 
  bordering 
  it, 
  that 
  such 
  results 
  would 
  

   not 
  be 
  one 
  of 
  the 
  consequences. 
  The 
  action 
  of 
  water 
  will 
  not 
  account 
  for 
  them. 
  

   Whether 
  by 
  "continual 
  dropping" 
  or 
  by 
  storms, 
  it 
  first 
  wears 
  away 
  the 
  soft 
  and 
  

   more 
  friable 
  parts, 
  leaving 
  the 
  harder 
  ; 
  it 
  destroys 
  shores 
  by 
  undermining, 
  and 
  

   then 
  grinding 
  it 
  leaves 
  irregular 
  jagged 
  surfaces. 
  These 
  irregular 
  surlaces, 
  if 
  

   upheaved 
  above 
  the 
  level 
  of 
  the 
  sea, 
  would 
  not 
  wear 
  away 
  regularly 
  by 
  the 
  

   weather 
  ; 
  the 
  inequalities 
  would 
  in 
  time 
  be 
  filled 
  by. 
  disintegrated 
  material, 
  

   but 
  the 
  surface 
  of 
  the 
  rock 
  would 
  not 
  bear 
  the 
  impress 
  of 
  a 
  planing 
  machine. 
  

   We 
  must 
  be 
  guided 
  in 
  great 
  measure 
  by 
  experience, 
  and 
  judging 
  by 
  our 
  knowl- 
  

   edge 
  of 
  present 
  local 
  glacier 
  action, 
  I 
  think 
  we 
  can 
  appeal 
  to 
  the 
  action 
  of 
  ice, 
  

   moving 
  slowly 
  but 
  surely, 
  as 
  a 
  great 
  planing 
  or 
  moulding 
  machine 
  ; 
  its 
  lines 
  of 
  

   movement 
  perhaps 
  controlled 
  by 
  masses 
  and 
  elevations 
  of 
  land 
  nbt 
  now 
  existing 
  

   as 
  such, 
  and 
  by 
  forces 
  no 
  longer 
  acting 
  on 
  such 
  a 
  scale. 
  We 
  may 
  suppose 
  a 
  

   great 
  ice 
  belt 
  to 
  have 
  existed 
  contiguous 
  to 
  the 
  continent 
  and 
  moving 
  parallel 
  

   with 
  it 
  ; 
  and 
  existing 
  at 
  the 
  same 
  period 
  with 
  the 
  ice 
  sheet 
  that 
  covered 
  the 
  

   continent 
  or 
  the 
  lower 
  parts 
  thereof. 
  Some 
  of 
  the 
  mechanical 
  effects 
  of 
  this 
  belt 
  

   may 
  be 
  those 
  we 
  see 
  exhibited 
  upon 
  the 
  islands 
  and 
  the 
  general 
  coast 
  line 
  ; 
  the 
  

   effects 
  of 
  the 
  latter 
  in 
  the 
  gorges 
  opening 
  upon 
  the 
  shores 
  in 
  the 
  interior 
  valleys, 
  

   and 
  on 
  the 
  mountain 
  flanks 
  when 
  at 
  right 
  angles 
  to 
  the 
  coast 
  line. 
  

  

  All 
  the 
  groovings 
  on 
  Vancouver 
  Island 
  and 
  the 
  islands 
  of 
  Washington 
  Sound, 
  

   at 
  the 
  southern 
  extremity 
  of 
  the 
  Gulf 
  of 
  Georgia, 
  point 
  to 
  the 
  agency 
  which 
  

   causes 
  them 
  as 
  moving 
  southward, 
  and 
  if 
  we 
  accept 
  an 
  ice 
  sheet 
  over 
  the 
  con- 
  

  

  