﻿HYDROLOGY 
  OB 
  1 
  NEW 
  YORK 
  311 
  

  

  These 
  figures 
  are 
  cited 
  to 
  show 
  that 
  in 
  years 
  of 
  low 
  rainfall 
  

   the 
  runoff 
  of 
  streams 
  tributary 
  to 
  the 
  Great 
  Lakes 
  is 
  low, 
  and 
  as 
  

   a 
  consequence 
  the 
  runoff 
  of 
  Niagara 
  river 
  will 
  necessarily 
  be 
  

   affected 
  thereby. 
  

  

  AMde 
  from 
  the 
  measurements 
  made 
  by 
  the 
  Board 
  of 
  Engineers 
  

   on 
  Deep 
  Waterways 
  in 
  1898, 
  the 
  most 
  elaborate 
  measurements 
  

   thus 
  far 
  made 
  are 
  those 
  of 
  the 
  Lake 
  Survey 
  in 
  1867 
  and 
  1869 
  which 
  

   are, 
  however, 
  extremely 
  unsatisfactory. 
  According 
  to 
  these 
  meas- 
  

   urements 
  the 
  mean 
  discharge, 
  rainfall 
  and 
  evaporation 
  from 
  the 
  

   Great 
  Lakes 
  for 
  the 
  year 
  1868, 
  in 
  cubic 
  feet 
  per 
  second, 
  were 
  as 
  

   follows 
  •} 
  

  

  -r 
  . 
  Mean 
  dis- 
  Total 
  rainfall 
  Evaporation 
  

  

  ^ 
  aKe 
  charge 
  on 
  basin 
  from 
  surface 
  

  

  Superior 
  86,000 
  171,430 
  27,690 
  

  

  Huron 
  and 
  Michigan 
  225,000 
  251,450 
  59,890 
  

  

  Erie 
  . 
  265,000 
  100,540 
  14,310 
  

  

  Total 
  523,420 
  101,890 
  

  

  According 
  to 
  the 
  Deep 
  Waterways 
  Commission's 
  tabulation 
  of 
  

   records 
  of 
  hights 
  of 
  the 
  Great 
  Lakes, 
  it 
  appears 
  that 
  the 
  water 
  

   level 
  fluctuated 
  through 
  a 
  series 
  of 
  years 
  to 
  the 
  extent 
  of 
  about 
  

   3.8 
  feet. 
  In 
  the 
  present 
  discussion 
  we 
  are 
  chiefly 
  concerned 
  with 
  

   the 
  fluctuations 
  of 
  Lake 
  Erie, 
  which 
  control 
  the 
  discharge 
  of 
  

   Niagara 
  river. 
  From 
  table 
  No. 
  44, 
  which 
  gives 
  the 
  mean 
  monthly 
  

   elevations 
  of 
  Lake 
  Erie 
  at 
  Buffalo 
  for 
  the 
  years 
  1865-1898, 
  in- 
  

   clusive, 
  it 
  appears 
  that 
  the 
  highest 
  mean 
  monthly 
  elevation 
  during 
  

   these 
  years 
  was 
  for 
  June, 
  1876, 
  when 
  the 
  mean 
  lake 
  surface 
  was- 
  

   ."j74.31 
  feet. 
  The 
  lowest 
  mean 
  monthly 
  elevation 
  for 
  the 
  period 
  was 
  

   for 
  November, 
  1895, 
  when 
  the 
  mean 
  for 
  the 
  month 
  was 
  570.49 
  feet. 
  

   The 
  range 
  in 
  the 
  mean 
  monthly 
  elevations 
  for 
  this 
  period 
  was 
  

   therefore 
  3.82 
  feet. 
  

  

  In 
  regard 
  to 
  table 
  No. 
  44 
  it 
  is 
  stated 
  in 
  the 
  Report 
  of 
  the 
  Board 
  

   of 
  Engineers 
  on 
  Deep 
  Waterways 
  that 
  the 
  uncertainty 
  concerning 
  

   the 
  stability 
  of 
  the 
  Buffalo 
  gage 
  previous 
  to 
  1896, 
  together 
  with 
  

   the 
  excessive 
  fluctuations 
  of 
  the 
  lake 
  level 
  at 
  Buffalo, 
  appear 
  to 
  

   make 
  the 
  Cleveland 
  gage 
  record 
  more 
  reliable, 
  and 
  it 
  has 
  therefore 
  

   been 
  used 
  in 
  determining 
  the 
  mean 
  monthly 
  elevations' 
  of 
  the 
  lake. 
  

  

  'These 
  figures 
  are 
  derived 
  from 
  Mr 
  Cooley's 
  Lakes 
  and 
  Gulf 
  Waterways, 
  

   as 
  corrected 
  and 
  given 
  in 
  the 
  Journal 
  of 
  the 
  Assoc, 
  of 
  Eng. 
  Soc., 
  Vol. 
  VIII 
  

   (March, 
  1889), 
  p. 
  132. 
  

  

  