﻿250 
  F. 
  B. 
  Taylor 
  — 
  Niagara 
  and 
  the 
  Great 
  Lakes. 
  

  

  themselves 
  have 
  almost 
  no 
  independent 
  existence. 
  If 
  any- 
  

   thing 
  happens 
  to 
  the 
  lakes 
  to 
  turn 
  their 
  discharge 
  in 
  some 
  

   other 
  direction 
  the 
  rivers 
  go 
  nearly 
  or 
  entirely 
  dry. 
  Niagara 
  

   is 
  one 
  of 
  these 
  rivers, 
  and 
  its 
  history 
  is 
  inseparable 
  from 
  that 
  

   of 
  the 
  lakes 
  above 
  it. 
  Prof. 
  Spencer 
  has 
  described 
  the 
  salient 
  

   features 
  of 
  the 
  Niagara 
  gorge, 
  and 
  has 
  also 
  given 
  many 
  

   important 
  facts 
  bearing 
  on 
  the 
  lake 
  history. 
  But 
  certain 
  facts 
  

   which 
  he 
  does 
  not 
  take 
  into 
  account 
  indicate 
  a 
  somewhat 
  dif- 
  

   ferent 
  lake 
  history, 
  and 
  in 
  consequence 
  a 
  different 
  Niagara 
  

   history 
  also. 
  The 
  lake 
  history 
  is 
  recorded 
  in 
  the 
  larger 
  

   characters, 
  and 
  it 
  seems 
  best 
  therefore 
  to 
  study 
  it 
  first. 
  Refer- 
  

   ence 
  will 
  be 
  made 
  in 
  the 
  following 
  pages 
  to 
  six 
  papers 
  in 
  

   which 
  the 
  writer's 
  observations 
  on 
  the 
  abandoned 
  shore 
  lines 
  

   of 
  the 
  upper 
  lakes 
  are 
  recorded.* 
  Another 
  paper 
  discussing 
  

   the 
  latest 
  chapter 
  in 
  the 
  history 
  of 
  the 
  Great 
  Lakes 
  also 
  

   belongs 
  to 
  this 
  series. 
  . 
  It 
  is 
  entitled, 
  " 
  The 
  Second 
  Lake 
  

   Algonquin. 
  "f 
  It 
  precedes 
  this 
  paper 
  in 
  order, 
  and 
  relates 
  to 
  

   the 
  lake 
  stages 
  following 
  next 
  after 
  those 
  discussed 
  here. 
  

   These 
  two 
  papers 
  together 
  cover, 
  in 
  a 
  preliminary 
  way, 
  the 
  

   whole 
  period 
  from 
  the 
  final 
  disappearance 
  of 
  the 
  great 
  Lauren- 
  

   tide 
  glacier 
  down 
  to 
  the 
  present 
  time. 
  But 
  they 
  do 
  not 
  

   include, 
  except 
  by 
  incidental 
  reference, 
  the 
  period 
  of 
  the 
  

   glacial 
  recession 
  with 
  its 
  lakes. 
  The 
  map 
  which 
  accompanies 
  

   this 
  paper 
  is 
  designed 
  to 
  show 
  within 
  its 
  limits 
  the 
  probable 
  

   distribution 
  of 
  land 
  at 
  the 
  maximum 
  of 
  marine 
  submergence, 
  

   and 
  also 
  the 
  extent 
  of 
  that 
  part 
  of 
  the 
  first 
  Lake 
  Algonquin 
  of 
  

   which 
  shore 
  lines 
  still 
  remain. 
  

  

  The 
  Three 
  Principal 
  Beaches. 
  

  

  After 
  the 
  glacial 
  recession 
  the 
  three 
  principal 
  critical 
  stages 
  

   in 
  the 
  recent 
  history 
  of 
  the 
  upper 
  Great 
  Lakes 
  are 
  marked 
  by 
  

   three 
  great 
  abandoned 
  beaches. 
  Two 
  of 
  these 
  are 
  lake 
  beaches 
  

   and 
  one 
  is 
  marine. 
  The 
  lake 
  beaches 
  mark 
  the 
  highest 
  stages 
  

   of 
  two 
  independent 
  epochs 
  of 
  Lake 
  Algonquin, 
  which 
  had 
  an 
  

   outlet 
  on 
  each 
  occasion 
  eastward 
  across 
  the 
  Nipissing 
  pass 
  at 
  

   North 
  Bay, 
  Ontario. 
  One 
  epoch 
  of 
  this 
  lake 
  existed 
  before 
  

   the 
  marine 
  invasion 
  and 
  the 
  other 
  after. 
  The 
  latest 
  one 
  I 
  

   have 
  called 
  the 
  second 
  Lake 
  Algonquin, 
  and 
  its 
  highest 
  shore 
  

  

  * 
  1. 
  ''Highest 
  Old 
  Shore 
  Line 
  on 
  Mackinac 
  Island," 
  this 
  Jour., 
  Ill, 
  vol. 
  

   xliii, 
  March, 
  1892; 
  2. 
  "The 
  Ancient 
  Strait 
  at 
  Nipissing," 
  Bull. 
  G-. 
  S. 
  A., 
  vol. 
  v, 
  

   1893 
  ; 
  3. 
  "A 
  Reconnaissance 
  of 
  the 
  Abandoned 
  Shore 
  Lines 
  of 
  Green 
  Bay," 
  Am. 
  

   G-eol., 
  vol. 
  xiii, 
  May, 
  1894; 
  4. 
  "A 
  Reconnaissance 
  of 
  the 
  Abandoned 
  Shore 
  Lines 
  

   of 
  the 
  South 
  Coast 
  of 
  Lake 
  Superior," 
  Am. 
  Geol., 
  vol. 
  xiii, 
  June, 
  1894 
  ; 
  5. 
  "The 
  

   Limit 
  of 
  Postglacial 
  Submergence 
  in 
  the 
  Highlands 
  East 
  of 
  Georgian 
  Bay," 
  Am. 
  

   Geol., 
  vol. 
  xiv, 
  Nov., 
  1894; 
  6. 
  "The 
  Munuscong 
  Islands," 
  Am. 
  Geol., 
  vol. 
  xv, 
  

   Jan 
  , 
  1895. 
  These 
  papers 
  will 
  be 
  referred 
  to 
  hereafter 
  by 
  number. 
  

  

  f 
  Am. 
  Geol, 
  vol. 
  xv, 
  Feb. 
  and 
  March, 
  1895. 
  

  

  