﻿830 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  4) 
  The 
  growth 
  of 
  aquatic 
  plants 
  on 
  long 
  levels 
  and 
  the 
  forma- 
  

   tion 
  of 
  sand 
  bars 
  in 
  the 
  canal, 
  which 
  have 
  tended 
  to 
  decrease 
  the 
  

   amount 
  passing. 
  

  

  Among 
  minor 
  sources 
  of 
  loss, 
  evaporation 
  and 
  absorption 
  by 
  

   growing 
  plants 
  may 
  be 
  mentioned, 
  both 
  of 
  which 
  vary 
  somewhat 
  

   in 
  different 
  years, 
  although 
  neither 
  can 
  be 
  considered 
  a 
  serious 
  

   source 
  of 
  loss. 
  

  

  A 
  study 
  of 
  all 
  the 
  measurements 
  in 
  detail 
  shows 
  that 
  in 
  an 
  

   artificial 
  channel 
  of 
  the 
  dimensions 
  of 
  the 
  original 
  Erie 
  canal, 
  

   there 
  should 
  be 
  provided 
  at 
  least 
  1.33 
  to 
  1.67 
  cubic 
  feet 
  per 
  

   second 
  per 
  mile, 
  exclusive 
  of 
  water 
  for 
  filling 
  and 
  for 
  lockages. 
  

  

  Using 
  the 
  data 
  of 
  the 
  measurements 
  of 
  1841, 
  Mr 
  Childs 
  arrived 
  

   at 
  the 
  water 
  supply 
  of 
  the 
  enlarged 
  canal 
  of 
  that 
  day 
  in 
  the 
  fol- 
  

   lowing 
  manner: 
  It 
  was 
  assumed 
  that 
  the 
  loss 
  by 
  nitration 
  

   through 
  the 
  bottom 
  and 
  sides 
  of 
  the 
  canal 
  would 
  be 
  as 
  the 
  square 
  

   root 
  of 
  the 
  pressure 
  or 
  depth 
  of 
  the 
  water, 
  and 
  as 
  the 
  area 
  of 
  the 
  

   surface 
  pressed. 
  Proceeding 
  on 
  this 
  assumption, 
  he 
  computed 
  

   the 
  quantity 
  required 
  to 
  supply 
  the 
  losses 
  from 
  nitration, 
  leakage, 
  

   and 
  evaporation 
  (in 
  the 
  enlarged 
  canal, 
  1840 
  to 
  1860), 
  at 
  3.17 
  

   cubic 
  feet 
  per 
  second 
  per 
  mile. 
  This 
  figure 
  was 
  subsequently 
  

   substantially 
  adopted 
  for 
  the 
  entire 
  enlarged 
  canal, 
  and, 
  with 
  the 
  

   exception 
  of 
  a 
  few 
  special 
  cases 
  is 
  still 
  in 
  use. 
  

  

  Adding 
  the 
  amount 
  required 
  for 
  lockages 
  at 
  lock 
  53, 
  Mr 
  Childs 
  

   placed 
  the 
  entire 
  supply 
  for 
  the 
  western 
  division, 
  from 
  Lockport 
  

   to 
  the 
  east 
  end, 
  at 
  3.48 
  cubic 
  feet 
  per 
  second 
  per 
  mile, 
  or 
  at 
  a 
  

   total 
  of 
  424 
  cubic 
  feet 
  per 
  second 
  for 
  122 
  miles 
  of 
  canal. 
  

  

  The 
  canal 
  enlargement 
  of 
  1895 
  contemplated 
  an 
  increase 
  in 
  

   depth 
  from 
  7 
  to 
  9 
  feet. 
  Taking 
  into 
  account 
  the 
  results 
  of 
  the 
  

   measurements 
  on 
  the 
  original 
  Erie 
  canal, 
  as 
  well 
  as 
  those 
  made 
  

   by 
  Mr 
  Childs 
  on 
  the 
  enlarged 
  canal 
  of 
  1840 
  to 
  1860, 
  it 
  has 
  been 
  

   concluded 
  that 
  the 
  proper 
  figure 
  for 
  water 
  supply 
  on 
  the 
  western 
  

   division, 
  to 
  which 
  the 
  studies 
  thus 
  far 
  specially 
  refer, 
  should 
  be 
  

   taken 
  at 
  from 
  4.17 
  to 
  4.50 
  cubic 
  feet 
  per 
  second 
  per 
  mile. 
  1 
  

  

  a 
  The 
  foregoing 
  statements 
  in 
  regard 
  to 
  measurements 
  of 
  water 
  supply 
  of 
  

   Erie 
  canal 
  are 
  abstracted 
  from 
  Report 
  on 
  the 
  Water 
  Supply 
  of 
  the 
  Western 
  

   Division 
  of 
  the 
  Erie 
  Canal, 
  by 
  the 
  writer, 
  and 
  are 
  to 
  be 
  found 
  in 
  Appenidx 
  I 
  

   to 
  the 
  An. 
  Rept 
  of 
  the 
  State 
  Engineer 
  and 
  Surveyor 
  for 
  the 
  fiscal 
  year 
  

   ending 
  September 
  30, 
  1896. 
  

  

  