﻿424 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  in 
  summer 
  and 
  no 
  injurious 
  excess 
  in 
  winter." 
  1 
  So 
  far 
  as 
  known 
  

   this 
  was 
  the 
  earliest 
  river 
  conservancy 
  commission. 
  This 
  com- 
  

   mission 
  does 
  not 
  appear 
  to 
  have 
  regulated 
  the 
  river 
  very 
  

   effectively, 
  since 
  many 
  inundations 
  occurred 
  afterwards, 
  and 
  in 
  

   1495 
  A. 
  D. 
  an 
  accurate 
  record 
  of 
  overflows 
  was 
  commenced. 
  The 
  

   flood 
  of 
  1495 
  was, 
  with 
  a 
  few 
  exceptions, 
  one 
  of 
  the 
  heaviest 
  

   known. 
  Since 
  that 
  time 
  serious 
  floods 
  have 
  occurred 
  on 
  the 
  Tiber 
  

   in 
  1530, 
  1557, 
  1598, 
  1606, 
  1637, 
  1660, 
  1686, 
  1702, 
  1750, 
  1805, 
  1843 
  r 
  

   1846 
  and 
  1870. 
  

  

  The 
  town 
  of 
  Ostia, 
  when 
  founded, 
  in 
  633 
  B. 
  0., 
  was 
  at 
  the 
  

   mouth 
  of 
  the 
  Tiber 
  and 
  soon 
  had 
  80,000 
  inhabitants. 
  In 
  the 
  

   course 
  of 
  years 
  Ostia 
  was 
  deprived 
  of 
  its 
  port 
  by 
  the 
  silt 
  carried 
  

   down 
  by 
  the 
  Tiber. 
  Thereupon 
  the 
  Emperor 
  Claudius, 
  about 
  the 
  

   beginning 
  of 
  the 
  Christian 
  era, 
  presented 
  to 
  the 
  Koman 
  senate 
  

   a 
  project 
  for 
  forming 
  a 
  port 
  three 
  miles 
  from 
  the 
  original 
  mouth. 
  

   A 
  basin, 
  with 
  two 
  moles, 
  a 
  breakwater, 
  towers 
  and 
  a 
  lighthouse^ 
  

   was 
  executed 
  and 
  a 
  canal 
  opened 
  to 
  connect 
  with 
  the 
  river. 
  This 
  

   canal 
  silted 
  up 
  towards 
  the 
  end 
  of 
  the 
  first 
  century. 
  The 
  Emperor 
  

   Trajan 
  repaired 
  the 
  port, 
  adding 
  an 
  internal 
  basin. 
  The 
  canal 
  

   which 
  still 
  forms 
  the 
  navigable 
  mouth 
  of 
  the 
  Tiber 
  was 
  opened 
  

   about 
  110 
  A. 
  D. 
  Plutarch, 
  in 
  his 
  life 
  of 
  Julius 
  Caesar, 
  states 
  that 
  

   Caesar 
  intended 
  to 
  remedy 
  the 
  evil 
  by 
  deepening 
  the 
  mouth 
  of 
  

   the 
  Tiber, 
  but 
  that 
  his 
  death 
  prevented 
  the 
  accomplishment 
  of 
  this 
  

   task. 
  

  

  An 
  extraordinary 
  inundation 
  of 
  the 
  Tiber 
  is 
  mentioned 
  by 
  the 
  

   younger 
  Pliny, 
  in 
  his 
  letter 
  to 
  Micrinus, 
  as 
  occurring 
  in 
  the 
  reign 
  

   of 
  Trajan, 
  who, 
  as 
  already 
  stated, 
  built 
  a 
  canal 
  which 
  still 
  exists. 
  

   The 
  present 
  length 
  of 
  this 
  canal 
  is 
  about 
  two 
  and 
  one-half 
  miles. 
  2 
  

  

  In 
  reference 
  to 
  the 
  reason 
  why 
  the 
  Koman 
  senatorial 
  river 
  

   conservancy 
  commission 
  did 
  not 
  succeed 
  there 
  is 
  but 
  one 
  remedy 
  

   which 
  can 
  be 
  applied 
  to 
  a 
  river 
  in 
  order 
  that 
  there 
  may 
  be 
  no 
  

   deficiency 
  in 
  summer 
  and 
  no 
  injurious 
  excess 
  in 
  winter, 
  namely, 
  

   water 
  storage. 
  The 
  valley 
  of 
  the 
  Tiber 
  does 
  not 
  present 
  the 
  

   proper 
  conditions 
  for 
  applying 
  this 
  remedy. 
  In 
  its 
  lower 
  reaches 
  

   the 
  Tiber 
  flows 
  through 
  a 
  broad 
  plain, 
  while 
  in 
  its 
  upper 
  reaches^ 
  

  

  iThe 
  Tiber 
  and 
  Its 
  Tributaries, 
  by 
  S. 
  A. 
  Smith, 
  1877, 
  p. 
  60. 
  

  

  2-W. 
  Shelford, 
  on 
  Non-tidal 
  Rivers, 
  Proc. 
  Inst. 
  C. 
  E., 
  Vol. 
  LXXXII, 
  pp. 
  

   7-8; 
  and 
  The 
  Tiber 
  and 
  Its 
  Delta, 
  by 
  Prof. 
  Ponzi, 
  Proc. 
  Inst. 
  O. 
  E., 
  Vol. 
  

   XLVII, 
  pp. 
  342-344. 
  

  

  