﻿NIAGARA 
  FALLS 
  AND 
  VICINITY 
  8$ 
  

  

  to 
  the 
  reign 
  of 
  King 
  David 
  at 
  Jerusalem." 
  Prof. 
  Hitchcock 
  be- 
  

   Heves 
  that 
  the 
  gorge 
  of 
  the 
  whirlpool 
  rapids 
  was 
  formed 
  while 
  

   Niagara 
  drained 
  only 
  the 
  diminished 
  Lake 
  Erie, 
  and 
  he 
  allows 
  a 
  

   period 
  of 
  7800 
  years 
  for 
  the 
  accomplishment 
  of 
  this 
  task. 
  For 
  the 
  

   erosion 
  of 
  the 
  remaining 
  portion 
  of 
  the 
  Niagara 
  gorge 
  Prof. 
  Hitch- 
  

   cock 
  allows 
  8156 
  years. 
  Thus 
  the 
  total 
  length 
  of 
  time 
  required 
  to 
  

   carve 
  out 
  the 
  Niagara 
  gorge 
  is 
  considered 
  by 
  Hitchcock 
  to 
  be 
  

   18,918 
  years. 
  

  

  The 
  reader 
  should 
  here 
  be 
  reminded 
  that 
  all 
  such 
  estimates 
  are 
  

   little 
  more 
  than 
  personal 
  opinions, 
  and 
  that 
  they 
  necessarily 
  vary 
  

   according 
  to 
  the 
  individual 
  predilections 
  as 
  to 
  greater 
  or 
  less 
  power 
  

   of 
  erosion 
  possessed 
  by 
  the 
  cataract 
  under 
  the 
  given 
  circumstances. 
  

   The 
  leading 
  questions 
  concerning 
  the 
  extent 
  of 
  the 
  preglacial 
  

   erosion 
  in 
  this 
  region, 
  and 
  the 
  changes 
  in 
  volume 
  of 
  water 
  during 
  

   the 
  lifetime 
  of 
  the 
  Niagara, 
  which 
  are 
  of 
  such 
  vital 
  importance 
  in 
  

   the 
  solution 
  of 
  this 
  problem, 
  are 
  by 
  no 
  means 
  satisfactorily 
  answered. 
  

   Nor 
  can 
  we 
  assume 
  that 
  we 
  are 
  familiar 
  with 
  all 
  the 
  factors 
  which 
  

   enter 
  into 
  the 
  equation. 
  There 
  may 
  be 
  still 
  undiscovered 
  causes 
  

   which 
  may 
  have 
  operated 
  to 
  lengthen 
  or 
  shorten 
  the 
  lifetime 
  of 
  this 
  

   great 
  river, 
  just 
  as 
  there 
  may 
  be, 
  and 
  probably 
  are, 
  factors 
  which 
  

   make 
  any 
  estimates 
  of 
  the 
  future 
  history 
  of 
  the 
  river 
  and 
  cataract 
  

   little 
  more 
  than 
  a 
  mere 
  speculation. 
  We 
  may 
  perhaps 
  say 
  that 
  our 
  

   present 
  knowledge 
  leads 
  us 
  to 
  believe 
  that 
  the 
  age 
  of 
  the 
  cataract 
  

   is 
  probably 
  not 
  less 
  than 
  10,000 
  nor 
  more 
  than 
  50,000 
  years. 
  

  

  