﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  

  

  32' 
  

  

  is 
  employed. 
  Gagings 
  are 
  also 
  sometimes 
  made 
  by 
  the 
  use 
  of 
  

   floats, 
  but 
  so 
  far 
  as 
  New 
  York 
  streams 
  are 
  concerned, 
  the 
  results 
  

   would 
  be 
  so 
  unsatisfactory 
  as 
  to 
  render 
  this 
  method 
  undesirable. 
  

   It 
  has 
  also 
  been 
  attempted 
  to 
  gage 
  the 
  flow 
  of 
  the 
  Mohawk 
  river 
  

   by 
  velocity 
  and 
  slope 
  measurements, 
  but 
  thus 
  far 
  the 
  results 
  are 
  

   not 
  satisfactory. 
  

  

  The 
  method 
  of 
  gaging 
  streams 
  by 
  the 
  use 
  of 
  the 
  current 
  meter 
  

   has 
  some 
  advocates 
  who 
  consider 
  it 
  superior 
  to 
  any 
  other. 
  Prob- 
  

   ably 
  the 
  reason 
  for 
  such 
  an 
  opinion 
  is 
  that 
  tests 
  of 
  a 
  current 
  

   meter 
  in 
  uniform 
  masonry 
  or 
  concrete 
  channels, 
  where 
  the 
  condi- 
  

   tions 
  are 
  the 
  most 
  favorable 
  possible 
  to 
  obtain, 
  have 
  shown 
  fairly 
  

   accurate 
  results 
  ; 
  but 
  in 
  a 
  shallow 
  stream, 
  flowing 
  over 
  a 
  boulder 
  

   bed, 
  the 
  conditions 
  are 
  so 
  different 
  as 
  to 
  make 
  rational 
  compari- 
  

   son 
  impossible. 
  The 
  current 
  meter 
  is 
  indeed 
  only 
  really 
  useful 
  

   when 
  the 
  following 
  conditions 
  obtain: 
  

  

  1) 
  A 
  smooth, 
  uniform 
  channel 
  for 
  a 
  considerable 
  distance 
  on 
  

   either 
  side 
  of 
  the 
  point 
  selected. 
  

  

  2) 
  Considerable 
  depth 
  at 
  the 
  point 
  selected 
  and 
  for 
  several 
  

   hundred 
  feet 
  to 
  either 
  side. 
  

  

  3) 
  Smooth 
  bottom 
  of 
  either 
  fine 
  sand, 
  hard 
  earth 
  or 
  very 
  fine 
  

   gravel. 
  

  

  4) 
  That 
  the 
  current 
  be 
  positive 
  and 
  of 
  some 
  little 
  velocity 
  

   throughout 
  the 
  whole 
  section. 
  

  

  New 
  York 
  streams 
  as 
  a 
  whole 
  do 
  not, 
  except 
  rarely, 
  answer 
  to 
  

   these 
  conditions. 
  They 
  are 
  usually 
  shallow, 
  rapid 
  flowing 
  in 
  

   places, 
  and 
  frequently 
  encumibered 
  with 
  boulders. 
  Current 
  meter 
  

   observation 
  may 
  be 
  at 
  times 
  from 
  100 
  per 
  cent 
  to 
  200 
  per 
  cent 
  in 
  

   error. 
  Broadly, 
  we 
  may 
  say 
  therefore 
  that 
  where 
  a 
  good 
  dam 
  

   exists 
  on 
  a 
  stream 
  the 
  gagings 
  should 
  preferably 
  be 
  first 
  of 
  all 
  

   made 
  at 
  this 
  point. 
  Or, 
  if 
  there 
  is 
  money 
  available, 
  a 
  special 
  

   weir 
  may 
  be 
  erected. 
  Failing 
  in 
  either 
  of 
  these 
  the 
  current 
  meter 
  

   is 
  a 
  proper 
  instrument, 
  with 
  due 
  understanding 
  of 
  the 
  limita- 
  

   tions 
  indicated 
  in 
  the 
  foregoing. 
  

  

  Streams 
  discussed 
  in 
  this 
  report. 
  It 
  is 
  impossible 
  to 
  give 
  in 
  the 
  

   following 
  discussion 
  the 
  measurements 
  of 
  all 
  the 
  streams 
  now 
  

   being 
  gaged 
  in 
  the 
  State 
  of 
  New 
  Y 
  r 
  ork, 
  and 
  accordingly 
  a 
  number 
  

   of 
  the 
  more 
  important 
  have 
  been 
  selected 
  for 
  which 
  the 
  records 
  

   will 
  be 
  given. 
  The 
  detail 
  of 
  the 
  balance 
  may 
  be 
  obtained 
  from 
  the 
  

  

  