﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  171 
  

  

  tory. 
  The 
  runoff 
  of 
  the 
  Hoosic 
  river 
  is, 
  without 
  doubt, 
  consider- 
  

   ably 
  less 
  than 
  that 
  of 
  the 
  main 
  Hudson. 
  The 
  average 
  precipitation 
  

   in 
  western 
  Massachusetts 
  from 
  1887 
  to 
  1895, 
  inclusive, 
  was 
  38.98 
  

   inches, 
  as 
  against 
  43.29 
  inches 
  in 
  the 
  northern 
  plateau 
  from 
  1889 
  

   to 
  1895, 
  inclusive, 
  a 
  difference 
  of 
  4.31 
  inches. 
  Should 
  such 
  dif- 
  

   ference 
  continue, 
  the 
  runoff 
  of 
  Hoosic 
  river 
  might 
  be 
  expected 
  to 
  

   be, 
  on 
  an 
  average, 
  about 
  20 
  inches. 
  Moreover, 
  the 
  Hudson 
  river 
  

   above 
  Glens 
  Falls 
  (catchment 
  about 
  2800 
  square 
  miles) 
  is 
  still 
  

   largely 
  in 
  forest 
  — 
  probably 
  about 
  85 
  per 
  cent 
  — 
  but 
  on 
  the 
  catch- 
  

   ments 
  of 
  Wood 
  creek, 
  Battenkill 
  and 
  Hoosic 
  rivers 
  the 
  proportion 
  

   of 
  forest 
  is 
  very 
  much 
  less 
  — 
  as 
  an 
  offhand 
  estimate, 
  the 
  writer 
  

   would 
  say 
  perhaps 
  20 
  to 
  30 
  per 
  cent. 
  The 
  runoff 
  of 
  Schroon 
  river, 
  

   which 
  is 
  perhaps 
  70 
  per 
  cent 
  of 
  an 
  equivalent 
  to 
  fairly 
  dense 
  

   forest, 
  is 
  for 
  four 
  years 
  26.84 
  inches. 
  There 
  is, 
  however, 
  some 
  

   doubt 
  whether 
  this 
  record 
  is 
  entirely 
  reliable, 
  and 
  for 
  the 
  present 
  

   it 
  is 
  not 
  intended 
  to 
  more 
  than 
  merely 
  call 
  attention 
  to 
  the 
  gen- 
  

   eral 
  proposition 
  that 
  this 
  stream, 
  which 
  issues 
  from 
  an 
  imper- 
  

   meable 
  catchment 
  with 
  70 
  per 
  cent 
  of 
  it 
  in 
  forest, 
  has 
  a 
  rather 
  

   large 
  runoff. 
  The 
  whole 
  catchment 
  area 
  of 
  the 
  Upper 
  Hudson 
  of 
  

   about 
  4500 
  square 
  miles, 
  will 
  probably 
  not 
  exceed 
  50 
  to 
  60 
  per 
  

   cent 
  of 
  forest. 
  

  

  The 
  following 
  are 
  the 
  catchment 
  areas 
  of 
  the 
  several 
  streams 
  

   here 
  considered 
  : 
  Hoosic, 
  711 
  square 
  miles 
  ; 
  Battenkill, 
  438 
  square 
  

   miles; 
  Sacandaga, 
  1057 
  square 
  miles, 
  and 
  Schroon 
  river, 
  570 
  

   square 
  miles. 
  

  

  The 
  Pequannock 
  river 
  in 
  New 
  Jersey, 
  not 
  far 
  from 
  the 
  New 
  

   York 
  line, 
  is 
  an 
  interesting 
  case. 
  This 
  stream 
  is 
  characterized 
  

   by 
  sharp 
  slopes 
  throughout 
  its 
  whole 
  extent. 
  Its 
  headwaters 
  are 
  

   at 
  an 
  elevation 
  of 
  about 
  1500 
  feet, 
  while 
  the 
  mouth 
  is 
  only 
  170 
  

   feet 
  above 
  tide. 
  The 
  catchment. 
  is 
  about 
  14 
  to 
  16 
  miles 
  long 
  by 
  4 
  

   to 
  7 
  miles 
  wide. 
  Mr 
  Vermeule 
  states 
  that 
  its 
  headwaters 
  lie 
  in 
  

   the 
  Precambrian 
  highlands. 
  The 
  sharp 
  slopes, 
  combined 
  with 
  

   small 
  catchment 
  area, 
  undoubtedly 
  account 
  for 
  the 
  relatively 
  

   large 
  runoff 
  of 
  this 
  stream. 
  There 
  is 
  also 
  an 
  uncertainty 
  of 
  1 
  or 
  

   2 
  inches 
  in 
  the 
  rainfall 
  record. 
  The 
  catchment 
  is 
  judged 
  by 
  the 
  

   writer 
  to 
  be 
  70 
  per 
  cent 
  forest. 
  

  

  