﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  357 
  

  

  We 
  have, 
  then, 
  a 
  total 
  area 
  of 
  the 
  basin 
  of 
  8360 
  square 
  miles. 
  1 
  

  

  The 
  rainfall 
  of 
  this 
  catchment 
  is 
  stated 
  in 
  the 
  Report 
  of 
  the 
  

   Board 
  of 
  Engineers 
  on 
  Deep 
  Waterways 
  at 
  an 
  average 
  of 
  about 
  

   33 
  inches 
  per 
  year. 
  But 
  table 
  No. 
  25 
  shows 
  that 
  for 
  the 
  12 
  years 
  

   from 
  1891 
  to 
  1902, 
  inclusive, 
  the 
  rainfall 
  of 
  Champlain 
  valley 
  was 
  

   37.06 
  inches. 
  

  

  The 
  lake 
  is 
  considered 
  as 
  terminating 
  on 
  the 
  south 
  at 
  White- 
  

   hall 
  and 
  on 
  the 
  north 
  at 
  St 
  Johns, 
  on 
  Richelieu 
  river. 
  The 
  low- 
  

   water 
  elevation 
  is 
  95.03 
  feet 
  + 
  T. 
  W\ 
  and 
  the 
  high 
  water, 
  103.78 
  

   feet 
  + 
  T. 
  W. 
  The 
  length 
  is 
  125 
  miles 
  from 
  Whitehall 
  to 
  St 
  

   Johns, 
  and 
  the 
  breadth 
  13 
  miles. 
  The 
  outlet 
  of 
  Lake 
  Champlain 
  

   is 
  Richelieu 
  river, 
  which 
  flows 
  northerly 
  across 
  the 
  Province 
  of 
  

   Quebec, 
  entering 
  the 
  St 
  Lawrence 
  at 
  Sorel. 
  The 
  length 
  of 
  the 
  

   river 
  is 
  75 
  miles. 
  It 
  receives 
  from 
  New 
  York 
  the 
  drainage 
  from 
  

   the 
  northeast 
  slope 
  of 
  the 
  Adirondacks, 
  amounting 
  to 
  35 
  per 
  

   cent 
  of 
  the 
  whole. 
  A 
  record 
  of 
  the 
  elevation 
  of 
  lake 
  surface 
  at 
  

   Rouses 
  Point 
  has 
  been 
  kept 
  by 
  the 
  United 
  States 
  Corps 
  of 
  Engi- 
  

   neers 
  since 
  1875. 
  

  

  In 
  1896 
  the 
  construction 
  of 
  a 
  power 
  plant 
  at 
  Chambly 
  was 
  

   begun 
  by 
  the 
  Royal 
  Electric 
  Company 
  of 
  Montreal. 
  The 
  dam 
  is 
  

   of 
  concrete 
  masonry, 
  strengthened 
  with 
  imbedded 
  iron 
  bars. 
  

   The 
  hight 
  from 
  apron 
  to 
  crest 
  is 
  18 
  feet, 
  affording 
  a 
  fall 
  of 
  28 
  

   feet 
  at 
  the 
  power-house. 
  A 
  calibration 
  curve 
  of 
  Richelieu 
  river 
  

   was 
  constructed 
  by 
  the 
  Board 
  of 
  Engineers 
  on 
  Deep 
  Waterways 
  

   by 
  comparing 
  the 
  computed 
  discharge 
  over 
  this 
  dam 
  with 
  the 
  

   corresponding 
  stage 
  of 
  Lake 
  Champlain 
  at 
  Fort 
  Montgomery, 
  

   and 
  taking 
  into 
  consideration 
  the 
  slope 
  of 
  Richelieu 
  river 
  in 
  the 
  

   intervening 
  distance 
  of 
  thirty-five 
  miles. 
  The 
  discharge 
  in 
  cubic 
  

   feet 
  per 
  second 
  has 
  been 
  deduced 
  from 
  this 
  curve. 
  

  

  The 
  record 
  of 
  Lake 
  Champlain 
  is 
  given 
  not 
  only 
  because 
  it 
  is 
  

   computed 
  over 
  a 
  dam, 
  but 
  because 
  it 
  is 
  a 
  long 
  record, 
  although 
  in 
  

   the 
  following 
  tables 
  it 
  has 
  only 
  been 
  taken 
  from 
  1880-1902, 
  in- 
  

   clusive. 
  The 
  catchment 
  area 
  of 
  7750 
  square 
  miles, 
  as 
  given 
  by 
  

   the 
  Board 
  of 
  Engineers 
  on 
  Deep 
  Waterways, 
  is 
  placed 
  at 
  the 
  

   head 
  of 
  the 
  tables. 
  

  

  iThe 
  preceding 
  figures 
  are 
  derived 
  from 
  the 
  Report 
  of 
  the 
  United 
  States 
  

   Deep 
  Waterways 
  Commission 
  (1896). 
  The 
  Board 
  of 
  Engineers 
  on 
  Deep 
  

   Waterways 
  gave 
  the 
  area 
  of 
  Lake 
  Champlain 
  at 
  437 
  square 
  miles 
  and 
  the 
  

   total 
  area 
  of 
  the 
  catchment 
  at 
  7,750 
  square 
  miles. 
  

  

  