﻿316 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  in 
  a 
  very 
  shallow 
  layer, 
  applied 
  continuously 
  for 
  a 
  considerable 
  period 
  of 
  time, 
  or 
  in 
  a 
  

   deep 
  layer 
  for 
  a 
  short 
  period. 
  

  

  If 
  the 
  flooding 
  take 
  the 
  form 
  of 
  a 
  standing 
  sheet 
  of 
  water, 
  it 
  may 
  be 
  quite 
  deep, 
  

   and 
  be 
  allowed 
  to 
  stand 
  until 
  it 
  all 
  settles 
  into 
  the 
  ground 
  and 
  evaporates. 
  A 
  fourth 
  

   method 
  is 
  to 
  combine 
  the 
  standing 
  sheet 
  with 
  the 
  flowing 
  one, 
  allowing 
  the 
  water 
  to 
  

   Btand 
  for 
  a 
  short 
  time 
  ; 
  then 
  draw 
  it 
  off 
  to 
  some 
  other 
  portion 
  of 
  the 
  field. 
  This 
  proc- 
  

   ess 
  is 
  more 
  applicable 
  to 
  large 
  farms 
  than 
  any 
  other 
  method. 
  It 
  costs 
  less, 
  generally 
  

   speaking, 
  to 
  prepare 
  land 
  for 
  irrigation 
  by 
  this 
  process, 
  and 
  the 
  work 
  can 
  be 
  done 
  

   more 
  quickly. 
  But 
  it 
  is 
  applicable 
  only 
  to 
  lands 
  of 
  gentle, 
  even 
  slopes, 
  and 
  a 
  soil 
  

   which 
  does 
  not 
  cake 
  after 
  being 
  soaked. 
  A 
  large 
  volume 
  of 
  water, 
  comparatively 
  

   speaking, 
  is 
  required, 
  and 
  there 
  is 
  danger 
  of 
  great 
  waste, 
  unless 
  the 
  irrigator 
  be 
  a 
  man 
  

   of 
  experience 
  and 
  the 
  ground 
  be 
  well 
  prepared. 
  There 
  are, 
  however, 
  many 
  crops 
  for 
  

   which 
  this 
  method 
  is 
  not 
  the 
  best. 
  

  

  The 
  second 
  method 
  — 
  by 
  ditching 
  — 
  is 
  also 
  varied, 
  to 
  a 
  considerable 
  extent, 
  in 
  practice. 
  

   It 
  may 
  be 
  carried, 
  flowing 
  constantly, 
  between 
  the 
  rows 
  of 
  plants, 
  whence 
  it 
  perco- 
  

   lates 
  laterally 
  through 
  the 
  intervening 
  soil, 
  or 
  the 
  water 
  may 
  be 
  kept 
  standing 
  in 
  

   ditches 
  between 
  the 
  rows. 
  In 
  this 
  case 
  the 
  ditches 
  should 
  be 
  larger 
  and 
  further 
  apart 
  

   than 
  in 
  the 
  previous 
  case. 
  In 
  the 
  case 
  of 
  very 
  open, 
  sandy 
  soils, 
  ditches 
  may 
  be 
  led 
  

   along 
  the 
  divides, 
  or 
  ridges, 
  at 
  greater 
  or 
  less 
  distances 
  apart, 
  the 
  lateral 
  percolatiou, 
  

   or 
  seepage, 
  being 
  sufficient 
  to 
  carry 
  the 
  water 
  over 
  the 
  whole 
  ground. 
  

  

  The 
  ditching 
  method 
  has 
  great 
  advantages 
  over 
  the 
  flooding 
  method 
  in 
  some 
  re- 
  

   spects. 
  It 
  costs, 
  in 
  general, 
  very 
  much 
  less 
  to 
  prepare 
  the 
  land 
  and 
  to 
  apply 
  the 
  water. 
  

   On 
  the 
  other 
  hand, 
  it 
  is 
  ordinarily 
  less 
  economical 
  of 
  water, 
  and 
  requires 
  more 
  time 
  

   in 
  the 
  application 
  of 
  it. 
  

  

  The 
  third 
  and 
  fourth 
  methods 
  are 
  not, 
  and 
  probably 
  never 
  will 
  be, 
  in 
  use 
  on 
  any 
  

   considerable 
  scale, 
  for 
  reasons 
  too 
  obvious 
  to 
  mention. 
  

  

  It 
  is 
  impossible 
  to 
  form 
  any 
  estimate 
  whatever 
  of 
  the 
  amount 
  of 
  money 
  at 
  present 
  

   invested 
  in 
  irrigation 
  works, 
  as 
  there 
  are 
  very 
  few 
  and 
  very 
  scattering 
  statistics 
  on 
  this 
  

   subject, 
  and 
  it 
  is 
  not 
  a 
  subject 
  upon 
  which 
  iufereuces 
  can 
  be 
  drawn 
  from 
  the 
  known 
  

   to 
  the 
  unknown. 
  Still 
  less 
  can 
  any 
  estimate 
  be 
  made 
  of 
  the 
  amount 
  which 
  would 
  be 
  

   required 
  to 
  construct 
  works 
  which 
  would 
  utilize 
  all 
  the 
  water 
  flowing 
  in 
  the 
  streams 
  

   and 
  thus 
  bring 
  the 
  maximum 
  of 
  land 
  under 
  cultivation. 
  Such 
  an 
  estimate, 
  even 
  

   in 
  the 
  roughest 
  form, 
  must 
  await 
  the 
  result 
  of 
  detailed 
  surveys, 
  and 
  the 
  development 
  

   of 
  definite 
  plans. 
  

  

  During 
  the 
  past 
  few 
  years 
  fertile 
  brains 
  have 
  been 
  busied 
  very 
  extensively 
  in 
  devis- 
  

   ing 
  ways 
  and 
  means 
  for 
  spending 
  money 
  to 
  no 
  purpose 
  on 
  grand 
  schemes 
  of 
  reservoirs 
  

   and 
  ditches. 
  These 
  schemes 
  have 
  come 
  from 
  all 
  grades 
  of 
  authority, 
  from 
  an 
  ex- 
  

   President 
  of 
  the 
  United 
  States, 
  who 
  knew 
  nothing 
  about 
  it, 
  down 
  to 
  a 
  county 
  surveyor, 
  

   who 
  ought 
  to 
  have 
  known 
  better. 
  

  

  None 
  of 
  the 
  streams 
  of 
  the 
  West 
  carry 
  sufficient 
  water, 
  or 
  command 
  land 
  in 
  suffi- 
  

   cient 
  amount, 
  to 
  warrant 
  the 
  construction 
  of 
  any 
  single 
  great 
  work 
  in 
  the 
  form 
  of 
  

   reservoirs 
  or 
  irrigating 
  canals. 
  The 
  fall 
  of 
  those 
  streams 
  is, 
  almost 
  without 
  ex- 
  

   ception, 
  sufficiently 
  great 
  to 
  allow 
  the 
  water 
  to 
  be 
  taken 
  up 
  to 
  the 
  bluff 
  lands 
  by 
  a 
  

   very 
  few 
  miles 
  of 
  ditch. 
  As 
  the 
  primary 
  and 
  almost 
  sole 
  object 
  of 
  a 
  long 
  canal, 
  

   parallel 
  to 
  the 
  stream 
  is 
  to 
  save 
  fall, 
  so 
  as 
  to 
  command 
  the 
  country, 
  it 
  will 
  be 
  seen 
  

   that 
  such 
  canals 
  are 
  doubly 
  unnecessary 
  in 
  this 
  region. 
  

  

  When 
  the 
  arable 
  lands 
  of 
  the 
  arid 
  region 
  are 
  developed 
  to 
  the 
  utmost 
  capacity 
  of 
  

   the 
  streams, 
  they 
  should 
  be 
  distributed 
  in 
  the 
  following 
  general 
  way. 
  Along 
  the 
  base 
  

   of 
  each 
  mountain 
  range 
  should 
  be 
  a 
  strip 
  of 
  land 
  parallel 
  to 
  the 
  range, 
  more 
  or 
  less 
  

   continuous, 
  and 
  of 
  greater 
  or 
  less 
  width, 
  in 
  proportion 
  to 
  the 
  amount 
  of 
  water 
  flow- 
  

   ing 
  from 
  the 
  mountains. 
  Down 
  each 
  stream 
  of 
  any 
  consequence 
  would 
  follow 
  a 
  belt 
  

   of 
  cultivated 
  land. 
  If 
  the 
  stream 
  has 
  a 
  rapid 
  fall 
  the 
  belt 
  may 
  be 
  broad, 
  and 
  extend 
  

   a 
  comparatively 
  short 
  distance 
  down 
  its 
  course. 
  If 
  its 
  current 
  be 
  sluggish, 
  the 
  strip 
  

   should 
  bo 
  narrow, 
  confined, 
  perhaps, 
  to 
  the 
  bottom-lands 
  merely, 
  and 
  may 
  extend 
  

   down 
  the 
  stream 
  a 
  long 
  distance. 
  The 
  details 
  would 
  depend 
  upon 
  local 
  circumstances. 
  

  

  