﻿362 
  Spencer 
  — 
  Origin 
  and 
  Age 
  of 
  the 
  Ontario 
  Shore-Line. 
  

  

  In 
  the 
  recession 
  of 
  Scarboro 
  bluffs 
  the 
  author, 
  just 
  mentioned, 
  

   seeks 
  to 
  confirm 
  his 
  estimate 
  of 
  the 
  age 
  of 
  the 
  Ontario 
  Beach 
  

   derived 
  from 
  Toronto 
  Island. 
  Such 
  requires 
  a 
  knowledge 
  of 
  

   the 
  amount 
  of 
  the 
  wave 
  encroachment 
  since 
  the 
  birth 
  of 
  the 
  

   Ontario 
  Beach. 
  From 
  the 
  gentle 
  slope 
  of 
  the 
  lake 
  floor 
  to 
  a 
  

   depth 
  of 
  100 
  feet, 
  at 
  a 
  point 
  13,000 
  feet 
  outward, 
  where 
  it 
  

   declines 
  more 
  rapidly, 
  he 
  concluded 
  that 
  the 
  Ontario 
  beach 
  had 
  

   an 
  amplitude 
  of 
  100 
  (in 
  place 
  of 
  20) 
  feet 
  and 
  had 
  risen 
  this 
  

   amount, 
  but 
  from 
  the 
  soundings 
  he 
  could 
  with 
  equal 
  value 
  have 
  

   selected 
  8,000 
  or 
  18,000 
  feet. 
  From 
  his 
  assumptions 
  here 
  he 
  

   again 
  gets 
  8,000 
  years 
  as 
  the 
  age 
  of 
  the 
  Ontario 
  Beach. 
  Using 
  

   the 
  other 
  figures, 
  just 
  mentioned, 
  a 
  student 
  could 
  just 
  as 
  well 
  

   obtain 
  an 
  age 
  of 
  5,000 
  or 
  11,000 
  years. 
  Any 
  hypothesis 
  based 
  

   on 
  such 
  variables 
  can 
  not 
  be 
  accepted. 
  But 
  more, 
  he 
  includes 
  

   in 
  the 
  Ontario 
  Beach 
  epoch 
  the 
  time 
  of 
  the 
  water 
  rising 
  100 
  

   feet 
  to 
  its 
  present 
  level, 
  thus 
  unconsciously 
  embracing 
  with 
  the 
  

   time 
  of 
  the 
  Ontario 
  Beach 
  a 
  long 
  period 
  before 
  the 
  begin- 
  

   ning 
  of 
  that 
  stage, 
  which 
  further 
  throws 
  confusion 
  into 
  his 
  

   hypothesis. 
  

  

  To 
  this 
  disjointed 
  speculation 
  of 
  the 
  age 
  of 
  the 
  Ontario 
  

   Beach 
  (8,000 
  years) 
  the 
  same 
  author 
  assigns, 
  without 
  offering 
  

   any 
  evidence, 
  an 
  equal 
  time 
  for 
  the 
  Iroquois 
  Beach, 
  and 
  then 
  

   adds 
  another 
  8,000 
  years 
  (which 
  he 
  himself 
  recognizes 
  as 
  only 
  

   a 
  " 
  guess 
  ") 
  for 
  the 
  time 
  intervening 
  between 
  the 
  Ontario 
  and 
  

   Iroquois 
  beaches 
  — 
  thus 
  making 
  24,000 
  (or 
  perhaps 
  27,000) 
  

   years 
  as 
  the 
  duration 
  of 
  post-Glacial 
  time.* 
  But 
  a 
  further 
  con- 
  

   tradiction 
  appears, 
  for 
  the 
  professor 
  has 
  shown 
  elsewhere 
  that 
  

   Lake 
  Iroquois 
  was 
  a 
  Glacial 
  lake, 
  consequently, 
  his 
  8,000 
  years 
  

   as 
  the 
  age 
  of 
  the 
  Iroquois 
  Beach 
  must 
  be 
  taken 
  away 
  from 
  his 
  

   post-Glacial 
  time, 
  leaving 
  16,000 
  years. 
  Such 
  d 
  priori 
  philoso- 
  

   phy 
  leaves 
  a 
  suspicion 
  that 
  its 
  author 
  had 
  some 
  speculation 
  to 
  

   support, 
  but 
  the 
  analyses 
  of 
  the 
  data 
  show 
  that 
  a 
  confusion 
  is 
  

   thereby 
  thrown 
  into 
  the 
  problem 
  of 
  Geological 
  time, 
  when 
  

   he 
  had 
  within 
  his 
  grasp 
  the 
  material 
  for 
  a 
  lasting 
  scientific 
  

   contribution 
  of 
  great 
  value 
  ; 
  and 
  if 
  the 
  confusion 
  be 
  not 
  ex- 
  

   punged 
  such 
  must 
  lead 
  to 
  the 
  retardation 
  of 
  scientific 
  research. 
  

  

  Washington, 
  D. 
  C. 
  

  

  * 
  From 
  resemblances 
  between 
  tile 
  Iroquois 
  and 
  Ontario 
  beaches 
  their 
  

   relative 
  duration 
  might 
  be 
  inferred 
  within 
  an 
  error 
  of 
  100 
  per 
  cent 
  ; 
  but 
  the 
  

   time 
  required 
  for 
  the 
  work 
  performed 
  between 
  these 
  epochs 
  is 
  not 
  compar- 
  

   able 
  to 
  either, 
  for 
  during 
  this 
  intervening 
  period 
  the 
  lake 
  level 
  fell 
  more 
  

   than 
  500 
  feet, 
  with 
  pauses, 
  and 
  rose 
  again 
  200 
  feet 
  with 
  the 
  partial 
  sub- 
  

   mergence 
  of 
  some 
  of 
  the 
  terraces. 
  During 
  this 
  intervening 
  period 
  great 
  

   denudation 
  was 
  effected, 
  as 
  shown 
  by 
  the 
  large 
  valley 
  excavated 
  by 
  the 
  Don. 
  

   The 
  varied 
  work 
  performed 
  at 
  this 
  time 
  was 
  vastly 
  greater 
  than 
  that 
  of 
  

   building 
  either 
  the 
  Iroquois 
  or 
  the 
  Ontario 
  Beach. 
  

  

  