﻿82 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  will 
  have 
  reached 
  the 
  upper 
  end 
  of 
  the 
  island 
  and 
  will 
  draw 
  off 
  all 
  

   the 
  waters 
  from 
  the 
  American 
  falls, 
  which 
  by 
  that 
  time 
  will 
  have 
  

   receded 
  only 
  about 
  half 
  way 
  to 
  the 
  Goat 
  island 
  bridge. 
  All 
  the 
  

   islands 
  will 
  then 
  be 
  joined 
  by 
  a 
  dry 
  channel 
  to 
  the 
  mainland, 
  an 
  

   event 
  which 
  was 
  anticipated 
  in 
  the 
  year 
  1848, 
  when, 
  owing 
  to 
  an 
  ice 
  

   blockade 
  in 
  the 
  Niagara 
  river 
  near 
  Buffalo, 
  the 
  American 
  fall 
  was 
  

   deprived 
  of 
  all 
  its 
  waters 
  for 
  a 
  day. 
  As 
  already 
  indicated 
  by 
  Gil- 
  

   bert's 
  forecast, 
  in 
  from 
  two 
  to 
  three 
  thousand 
  years 
  from 
  now, 
  or 
  

   long 
  before 
  the 
  falls 
  have 
  even 
  reached 
  the 
  head 
  of 
  Grand 
  island, 
  

   the 
  drainage 
  of 
  the 
  great 
  lakes 
  will 
  be 
  reversed, 
  provided 
  the 
  land 
  

   continues 
  to 
  rise 
  northward 
  as 
  it 
  has 
  in 
  the 
  past, 
  and 
  Niagara 
  will 
  

   carry 
  only 
  the 
  drainage 
  of 
  the 
  immediate 
  neighborhood. 
  From 
  a 
  

   majestic 
  cataract 
  it 
  will 
  dwindle 
  to 
  a 
  few 
  threads 
  of 
  water 
  falling 
  over 
  

   the 
  great 
  precipice, 
  such 
  as 
  may 
  be 
  seen 
  during 
  the 
  summer 
  season 
  

   in 
  the 
  upper 
  falls 
  of 
  the 
  Genesee 
  at 
  Rochester. 
  

  

  Age 
  of 
  Niagara 
  

  

  Speculations 
  as 
  to 
  the 
  age 
  of 
  Niagara 
  have 
  been 
  indulged 
  in 
  ever 
  

   since 
  men 
  began 
  to 
  recognize 
  that 
  the 
  river 
  had 
  carved 
  its 
  own 
  

   channel. 
  The 
  length 
  of 
  time 
  required 
  for 
  the 
  excavation 
  of 
  Niagara 
  

   gorge 
  is 
  not 
  merely 
  of 
  local 
  interest 
  but 
  serves 
  as 
  a 
  basis 
  for 
  esti- 
  

   mating 
  the 
  length 
  of 
  time 
  since 
  the 
  disappearance 
  of 
  the 
  Laurentian 
  

   glaciers 
  from 
  this 
  region, 
  and 
  incidentally 
  it 
  has 
  served 
  as 
  a 
  chro- 
  

   nometer 
  for 
  approximately 
  measuring 
  the 
  age 
  of 
  the 
  human 
  race 
  

   on 
  this 
  continent. 
  From 
  insufficient 
  data 
  Sir 
  Charles 
  Lyell 
  esti- 
  

   mated 
  the 
  age 
  of 
  Niagara 
  at 
  36,000 
  years, 
  while 
  others 
  have 
  assumed 
  

   an 
  age 
  as 
  high 
  as 
  100,000 
  years 
  or 
  more. 
  

  

  No 
  reliable 
  basis 
  for 
  estimating 
  the 
  age 
  of 
  the 
  gorge 
  was 
  known 
  

   till 
  a 
  series 
  of 
  surveys 
  were 
  made 
  to 
  determine 
  the 
  actual 
  recession 
  

   of 
  the 
  cataracts. 
  From 
  these 
  the 
  following 
  variable 
  rates 
  of 
  reces- 
  

   sion 
  of 
  the 
  two 
  falls 
  have 
  been 
  obtained.^ 
  

  

  ^Report 
  N. 
  Y. 
  state 
  engineer. 
  1890. 
  

  

  