﻿"92 
  REPORT 
  UNITED 
  STATES- 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  a 
  storm 
  they 
  simply 
  disappear 
  from 
  view 
  as 
  the 
  clouds 
  obscure 
  the 
  sky. 
  But 
  if 
  a 
  

   wind 
  adverse 
  to 
  their 
  course 
  meets 
  them 
  they 
  come 
  down 
  in 
  large 
  numbers. 
  The 
  2d, 
  

   3d, 
  and 
  4th, 
  up 
  to 
  3 
  p. 
  m., 
  were 
  nearly 
  or 
  quite 
  clear 
  and 
  wind 
  continued 
  southerly. 
  

  

  1868, 
  August 
  8, 
  10, 
  and 
  11. 
  — 
  Each 
  day 
  much 
  the 
  same 
  calm, 
  but 
  few 
  clouds 
  in 
  the 
  

   forenoon, 
  and 
  immense 
  swarms 
  passing 
  from 
  south 
  to 
  north 
  ; 
  but 
  each 
  day 
  from 
  1 
  to 
  3 
  

   p. 
  m. 
  a 
  northwest 
  to 
  north 
  wind 
  from 
  strong 
  to 
  fresh 
  brought 
  them 
  down 
  like 
  a 
  hail- 
  

   storm. 
  

  

  Many 
  memoranda 
  were 
  made 
  of 
  flights 
  and 
  arrivals 
  from 
  1868 
  to 
  1875 
  too 
  lengthy 
  

   to 
  copy, 
  but 
  all 
  to 
  this 
  general 
  effect 
  : 
  They 
  were 
  invisible 
  when 
  passing 
  over-head 
  

   until 
  near 
  9 
  o'clock 
  a. 
  m., 
  or 
  in 
  the 
  afternoon 
  much 
  after 
  3 
  o'clock. 
  They 
  must 
  be 
  

   nearly 
  in 
  a 
  line 
  with 
  the 
  sun 
  to 
  be 
  visible, 
  and 
  the 
  sun 
  falling 
  below 
  this 
  angle 
  of 
  

   some 
  45° 
  leaving 
  untold 
  myriads 
  of 
  them 
  in 
  the 
  air 
  ; 
  yet 
  I 
  never 
  knew 
  them 
  to 
  come 
  down 
  

   after 
  that 
  time 
  (unless 
  driven 
  down 
  by 
  an 
  adverse 
  wind). 
  Again 
  in 
  June, 
  1875, 
  from 
  

   the 
  13th 
  to 
  the 
  24th, 
  on 
  every 
  day, 
  if 
  the 
  sun 
  shone 
  out, 
  they 
  were 
  passing 
  over, 
  but 
  

   none 
  were 
  seen 
  descending 
  at 
  night. 
  The 
  locust 
  rarely 
  moves 
  much 
  in 
  the 
  morning 
  

   till 
  the 
  sun 
  warms 
  up 
  the 
  air 
  as 
  also 
  the 
  locust, 
  and 
  I 
  have 
  no 
  record 
  or 
  recollection 
  

   of 
  their 
  rising 
  till 
  from 
  9 
  a. 
  m. 
  to 
  11 
  a. 
  m., 
  yet 
  the 
  mass 
  above 
  would 
  be 
  seen 
  by 
  or 
  

   before 
  that 
  time 
  high 
  up 
  on 
  their 
  regular 
  course. 
  Such 
  immense 
  masses 
  could 
  not 
  de- 
  

   scend 
  each 
  night 
  without 
  literally 
  covering 
  or 
  burying 
  the 
  ground. 
  

  

  Does 
  the 
  main 
  army 
  continue 
  its 
  march 
  night 
  and 
  day, 
  only 
  dropping 
  a 
  few 
  

   stragglers 
  as 
  they 
  become 
  too 
  weary 
  or 
  hungry 
  to 
  keep 
  up 
  ? 
  

  

  1 
  6. 
  August, 
  1868. 
  — 
  On 
  the 
  8th, 
  18th, 
  19th, 
  and 
  20th, 
  days 
  of 
  flight, 
  the 
  thermometer 
  

   ranged 
  from 
  57° 
  to 
  86°. 
  

  

  July, 
  1875. 
  — 
  From 
  the 
  13th 
  to 
  the 
  22d 
  the 
  maximum 
  temperature 
  was 
  from 
  70° 
  to 
  

   94°, 
  the 
  minimum 
  from 
  52° 
  to 
  66°. 
  

  

  June 
  14 
  and 
  16. 
  — 
  The 
  flight 
  was 
  from 
  northeast 
  to 
  north 
  on 
  northerly 
  winds; 
  57° 
  to 
  

   79°. 
  

  

  August 
  24 
  to 
  28.— 
  Northeast 
  wind; 
  59° 
  to 
  86°. 
  

  

  August 
  29. 
  — 
  Wind 
  south, 
  immense 
  numbers 
  ; 
  74° 
  to 
  86°. 
  

  

  I 
  do 
  not 
  think 
  they 
  rise 
  to 
  join 
  the 
  crowd 
  above 
  (I 
  never 
  knew 
  them 
  to 
  rise 
  unless 
  

   there 
  were 
  swarms 
  passing 
  over 
  at 
  the 
  time) 
  in 
  cloudy 
  weather. 
  Still, 
  when 
  in 
  regular 
  

   flight 
  I 
  do 
  not 
  think 
  clouds 
  stop 
  them, 
  although 
  it 
  obscures 
  them 
  from 
  view. 
  As 
  the 
  

   sun 
  has 
  appeared 
  through 
  broken 
  clouds 
  I 
  have 
  often 
  seen 
  them 
  passing, 
  while 
  when 
  

   the 
  sun 
  was 
  obscured 
  they 
  were 
  invisible. 
  

  

  1 
  a 
  and 
  c. 
  Invariably 
  in 
  the 
  direction 
  of 
  the 
  wind, 
  be 
  its 
  force 
  more 
  or 
  less. 
  

  

  1 
  c. 
  By 
  arranging 
  the 
  focal 
  distance 
  of 
  a 
  spy-glass 
  at 
  a 
  known 
  horizontal 
  distance, 
  

   and 
  comparison 
  of 
  appearance, 
  and 
  size 
  of 
  locusts 
  ; 
  I 
  think 
  the 
  passing 
  swarms 
  are 
  

   from 
  ^ 
  to 
  1 
  mile 
  high, 
  varying 
  at 
  times, 
  probably 
  seeking 
  currents 
  of 
  wind 
  of 
  greater 
  

   or 
  less 
  velocity. 
  In 
  case 
  of 
  sudden 
  or 
  heavy 
  rains, 
  when 
  the 
  air 
  was 
  full 
  of 
  them, 
  none 
  

   of 
  consequence 
  came 
  down 
  with 
  the 
  rain. 
  It 
  seems 
  impossible 
  that 
  they 
  could 
  fly 
  

   through 
  the 
  storm. 
  Do 
  they 
  rise 
  above 
  it 
  ? 
  In 
  heavy 
  swarms 
  my 
  glasses 
  show 
  them 
  as 
  

   •dense 
  as 
  they 
  can 
  move 
  without 
  interference. 
  

  

  The 
  extent 
  of 
  the 
  swarm 
  it 
  is 
  difficult 
  to 
  ascertain, 
  as 
  the 
  observer 
  can 
  only 
  see 
  a 
  

   small 
  belt. 
  They 
  may 
  extend 
  indefinitely 
  right 
  or 
  left. 
  During 
  the 
  flight 
  from 
  June 
  

   15 
  to 
  25 
  of 
  1875, 
  I 
  telegraphed 
  east 
  and 
  west. 
  I 
  found 
  a 
  continuous 
  line 
  moving 
  

   northward 
  of 
  110 
  miles, 
  and 
  then 
  somewhat 
  broken 
  40 
  miles 
  farther. 
  The 
  movements 
  

   of 
  the 
  winds 
  for 
  five 
  days 
  (15th 
  to 
  20th) 
  averaged 
  about 
  10 
  miles 
  per 
  hour 
  ; 
  and 
  the 
  

   locust 
  evidently 
  moved 
  considerably 
  faster 
  than 
  the 
  wind, 
  at 
  least 
  15 
  miles 
  per 
  hour. 
  

   The 
  swarm 
  I 
  estimated 
  at 
  from 
  one-quarter 
  to 
  one-half 
  mile 
  deep. 
  It 
  seemed 
  like 
  pierc- 
  

   ing 
  the 
  milky-way 
  of 
  the 
  heavens; 
  my 
  glass 
  found 
  no 
  limits 
  to 
  them. 
  They 
  might 
  

   have 
  been 
  a 
  mile 
  or 
  more 
  in 
  depth. 
  They 
  wore 
  visible 
  from 
  six 
  to 
  seven 
  hours 
  of 
  each 
  

   of 
  the 
  successive 
  five 
  days, 
  and 
  I 
  can 
  see 
  no 
  reason 
  to 
  suppose 
  that 
  their 
  flight 
  was 
  

   checked 
  during 
  the 
  whole 
  five 
  days. 
  If 
  so, 
  the 
  army 
  in 
  the 
  line 
  of 
  advance 
  would 
  be 
  

   120 
  hours 
  by 
  15 
  miles 
  per 
  hour 
  = 
  1,800 
  miles 
  in 
  length, 
  and 
  say 
  at 
  even 
  110 
  miles 
  in 
  

   width, 
  an 
  area 
  of 
  198,600 
  miles! 
  and 
  then 
  from 
  one-quarter 
  to 
  one-half 
  mile 
  deep. 
  

   Thi.s 
  is 
  utterly 
  Incredible, 
  ye1 
  bow 
  can 
  we 
  pul 
  it 
  aside 
  :' 
  

  

  