﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  453 
  

  

  except 
  for 
  slight 
  rises 
  due 
  to 
  rainfall 
  on 
  September 
  7 
  and 
  8, 
  and 
  

   September 
  15 
  and 
  18, 
  until 
  October 
  15, 
  when 
  the 
  flow 
  rose 
  to 
  a 
  

   little 
  over 
  2000 
  cubic 
  feet 
  per 
  second. 
  At 
  Rochester, 
  on 
  the 
  other 
  

   hand, 
  the 
  effect 
  of 
  the 
  heavy 
  rainfall 
  of 
  August 
  29, 
  was 
  to 
  so 
  far 
  

   replenish 
  the 
  depleted 
  ground 
  water 
  of 
  the 
  flats 
  as, 
  with 
  the 
  excep- 
  

   tion 
  of 
  a 
  few 
  days 
  in 
  the 
  early 
  part 
  of 
  October, 
  when 
  the 
  flow 
  

   dropped 
  to 
  about 
  600 
  cubic 
  feet 
  per 
  second, 
  to 
  keep 
  the 
  flow 
  up 
  to 
  

   about 
  800 
  cubic 
  feet 
  per 
  second, 
  for 
  the 
  balance 
  of 
  the 
  year. 
  

  

  The 
  storage 
  value 
  of 
  the 
  Genesee 
  river 
  flats. 
  In 
  order 
  to 
  

   further 
  illustrate 
  the 
  great 
  storage 
  value 
  of 
  the 
  flats, 
  we 
  may 
  note 
  

   that 
  the 
  catchment 
  area 
  at 
  Rochester 
  is 
  2.3 
  times 
  that 
  at 
  Mount 
  

   Morris; 
  hence, 
  for 
  proportionate 
  yields 
  the 
  flow 
  at 
  Rochester 
  

   should 
  be 
  2.3 
  times 
  that 
  at 
  Mount 
  Morris. 
  During 
  August, 
  1893, 
  

   at 
  a 
  time 
  of 
  extreme 
  dry 
  weather, 
  the 
  flow 
  at 
  Rochester 
  was 
  3.7 
  

   times 
  that 
  at 
  Mount 
  Morris, 
  and 
  after 
  the 
  extreme 
  storm 
  of 
  

   August 
  29, 
  which 
  replenished 
  the 
  ground 
  water 
  of 
  the 
  flats, 
  the 
  

   flow 
  at 
  Rochester, 
  during 
  the 
  entire 
  replenishing 
  period 
  ( 
  Septem- 
  

   ber, 
  October 
  and 
  November) 
  was 
  four 
  times 
  that 
  at 
  Mount 
  Morris. 
  

  

  A 
  knowledge 
  of 
  this 
  constant 
  accession 
  of 
  large 
  quantities 
  of 
  

   water 
  from 
  the 
  flats 
  leads 
  to 
  another 
  conclusion 
  of 
  great 
  practical 
  

   importance, 
  namely, 
  that 
  we 
  may 
  expect 
  to 
  realize 
  at 
  Rochester 
  

   the 
  full 
  value 
  of 
  all 
  the 
  water 
  added 
  from 
  the 
  storage 
  at 
  Mount 
  

   Morris 
  ; 
  that 
  is, 
  an 
  addition 
  of, 
  say, 
  700 
  cubic 
  feet 
  per 
  second 
  at 
  

   Mount 
  Morris, 
  in 
  time 
  of 
  low 
  water, 
  will 
  be 
  likely 
  to 
  increase 
  the 
  

   flow 
  at 
  Rochester 
  700 
  cubic 
  feet 
  per 
  second 
  more 
  than 
  it 
  would 
  

   have 
  been 
  without 
  such 
  addition. 
  

  

  In 
  order 
  to 
  show 
  more 
  strikingly 
  the 
  value 
  of 
  the 
  flats 
  for 
  such 
  

   storage, 
  we 
  will 
  now 
  compute 
  the 
  amount 
  stored 
  and 
  held 
  back 
  

   therein. 
  

  

  Referring 
  to 
  Rafter 
  and 
  Baker's 
  Sewage 
  Disposal 
  in 
  the 
  United 
  

   States, 
  page 
  165, 
  we 
  find 
  a 
  tabulated 
  statement 
  of 
  the 
  per 
  cent 
  

   of 
  empty 
  space 
  in 
  a 
  number 
  of 
  soils, 
  as 
  follows 
  : 
  

  

  Per 
  cent 
  

  

  In 
  Illinois 
  prairie 
  soil, 
  the 
  voids 
  are 
  55.2 
  

  

  In 
  East 
  Windsor, 
  Connecticut, 
  clay 
  soil, 
  the 
  voids 
  are. 
  . 
  . 
  48.3 
  

  

  In 
  coarse 
  river 
  sand, 
  the 
  voids 
  are 
  from 
  38 
  . 
  4 
  to 
  41.0 
  

  

  In 
  subsoils, 
  the 
  voids 
  are 
  from 
  34 
  . 
  6 
  to 
  42 
  . 
  6 
  

  

  In 
  blowing 
  sands, 
  the 
  voids 
  are 
  44 
  .7 
  

  

  