﻿dr. 
  child's 
  letter. 
  93 
  

  

  All 
  my 
  records 
  and 
  recollections 
  say 
  they 
  rise 
  to 
  depart 
  between 
  9 
  a. 
  m. 
  and 
  12 
  m., 
  

   and 
  never 
  unless 
  there 
  is 
  a 
  swarm 
  in 
  motion 
  overhead. 
  

  

  2 
  a. 
  June 
  13 
  to 
  15, 
  18G8. 
  — 
  Towards 
  northwest 
  on 
  a 
  southeast 
  wind. 
  

  

  1869, 
  June 
  20. 
  — 
  After 
  a 
  four 
  days' 
  southerly 
  wind, 
  they 
  came 
  down 
  largely 
  on 
  a 
  north 
  

   wind. 
  

  

  1875, 
  June- 
  13 
  to 
  22. 
  — 
  The 
  air 
  was 
  full 
  of 
  them 
  every 
  day, 
  the 
  wind 
  generally 
  from 
  

   south 
  or 
  southeast. 
  The 
  locusts 
  went 
  with 
  it 
  ; 
  two 
  short 
  changes 
  to 
  northeast 
  brought 
  

   them 
  to 
  the 
  ground. 
  

  

  June 
  24. 
  — 
  During 
  the 
  forenoon 
  the 
  wind 
  was 
  light 
  from 
  the 
  north, 
  and 
  locusts 
  with 
  

   it 
  (a 
  rare 
  case). 
  At 
  noon 
  full 
  calm, 
  and 
  progress 
  stopped. 
  They 
  circled 
  round 
  and 
  

   round, 
  and 
  many 
  came 
  down. 
  

  

  2oth 
  to 
  28th. 
  — 
  Wind 
  southeast. 
  Locusts 
  on 
  it 
  to 
  northwest. 
  

  

  June 
  14 
  and 
  15, 
  1876. 
  — 
  To 
  the 
  southward 
  on 
  northerly 
  winds. 
  

  

  August 
  10. 
  — 
  No 
  wind 
  and 
  no 
  general 
  course. 
  

  

  August 
  24 
  and 
  25. 
  — 
  Northwest 
  and 
  northeast 
  winds 
  brought 
  a 
  few. 
  

  

  On 
  the 
  above 
  times 
  the 
  winds 
  were 
  generally 
  light, 
  from 
  five 
  to 
  ten 
  miles 
  per 
  hour. 
  

   The 
  weather 
  fair, 
  of 
  course, 
  where 
  the 
  locusts 
  were 
  visible, 
  for 
  they 
  are 
  invisible 
  in 
  

   cloudy 
  weather. 
  

  

  2 
  b. 
  The 
  temperature 
  at 
  the 
  time 
  of 
  rising 
  has 
  ranged 
  from 
  70° 
  to 
  90°. 
  Cold 
  or 
  cool 
  

   weather 
  renders 
  them 
  sluggish, 
  

  

  2 
  c. 
  The 
  direction 
  always 
  corresponds 
  with 
  the 
  flocks 
  above, 
  of 
  which 
  I 
  have 
  spoken 
  

   above. 
  I 
  have 
  rarely 
  seen 
  a 
  large 
  number 
  rise 
  at 
  once. 
  The 
  lower 
  air 
  will 
  be 
  very 
  

   full 
  of 
  them, 
  but 
  at 
  least 
  four-fifths 
  of 
  them 
  rise, 
  take 
  long 
  horizontal 
  flights, 
  but 
  

   seemingly" 
  unable 
  to 
  rise, 
  come 
  to 
  the 
  ground 
  again. 
  I 
  presume 
  they 
  have 
  to 
  make 
  

   several 
  attempts 
  before 
  they 
  succeed. 
  

  

  August 
  24, 
  1876. 
  — 
  I 
  first 
  noticed 
  them. 
  I 
  know 
  nothing 
  of 
  any 
  marching 
  or 
  travel- 
  

   ing 
  except 
  as 
  they 
  march 
  across 
  a 
  field 
  of 
  grain 
  or 
  other 
  food 
  and 
  leave 
  a 
  bare 
  plain 
  

   behind 
  them. 
  When 
  on 
  the 
  wing 
  I 
  am 
  inclined 
  to 
  think 
  they 
  fly 
  all 
  night. 
  Their 
  

   movement 
  must 
  be 
  regulated 
  largely 
  by 
  the 
  wind 
  they 
  are 
  on, 
  and 
  this 
  they 
  out-travel, 
  

   according 
  to 
  my 
  observation. 
  

  

  Yesterday, 
  July 
  22, 
  about 
  noon, 
  I 
  noticed 
  they 
  were 
  passing 
  over 
  in 
  very 
  large 
  num- 
  

   bers; 
  a 
  light 
  southerly 
  wind 
  blew 
  them 
  northward. 
  I 
  gave 
  my 
  entire 
  attention 
  to 
  

   them, 
  aixd 
  watched 
  them, 
  assisted 
  with 
  a 
  spyglass. 
  The 
  swarm 
  was 
  of 
  great 
  depth, 
  

   at 
  least 
  one-quarter 
  mile 
  ; 
  how 
  wide 
  I 
  had 
  no 
  means 
  of 
  determining. 
  Through 
  some 
  

   peculiarity 
  of 
  the 
  atmosphere, 
  probably 
  aided 
  by 
  a 
  lower 
  flight 
  than 
  usual 
  (the 
  bar- 
  

   ometer 
  indicated 
  from 
  30.019 
  to 
  30.062 
  inches 
  pressure) 
  I 
  kept 
  them 
  in 
  view 
  until 
  after 
  

   7 
  p. 
  m. 
  with 
  no 
  perceptible 
  diminution 
  of 
  numbers. 
  Careful 
  observations 
  in 
  the 
  even- 
  

   ing, 
  and 
  again 
  this 
  morning, 
  show 
  not 
  a 
  single 
  one 
  on 
  the 
  ground. 
  

  

  At 
  8.30 
  this 
  morning 
  I 
  succeeded 
  in 
  getting 
  sight 
  of 
  them 
  again 
  overhead, 
  and 
  as 
  

   the 
  sun 
  rose 
  higher 
  developed 
  numbers 
  about 
  the 
  same 
  as 
  yesterday. 
  (Query: 
  was 
  the 
  

   flight 
  continuous 
  through 
  the 
  night 
  ?) 
  

  

  For 
  several 
  years 
  I 
  have 
  observed 
  the 
  locust, 
  and 
  have 
  seen 
  no 
  exception 
  to 
  the 
  gen- 
  

   eral 
  rule 
  that 
  it 
  is 
  very 
  sluggish 
  in 
  the 
  cool 
  of 
  the 
  morning, 
  i. 
  e., 
  on 
  the 
  earth. 
  It 
  does 
  

   not 
  leave 
  its 
  perch, 
  roost, 
  or 
  bed 
  until 
  the 
  air 
  is 
  warmed 
  up 
  from 
  8 
  to 
  10 
  a. 
  m. 
  Sup- 
  

   posing 
  this 
  swarm 
  had 
  descended 
  somewhere 
  ; 
  it 
  must 
  have 
  literally 
  more 
  than 
  covered 
  

   the 
  ground 
  ; 
  yet, 
  in 
  violation 
  of 
  their 
  general 
  habit 
  of 
  late 
  rising, 
  here 
  they 
  are 
  at 
  

   8| 
  a. 
  m. 
  in 
  regular 
  flight 
  overhead. 
  The 
  thermometer 
  last 
  night 
  was 
  at 
  68°, 
  this 
  morn- 
  

   ing 
  at 
  7 
  a. 
  m. 
  at 
  64°. 
  A 
  minimum 
  thermometer 
  fell 
  during 
  the 
  night 
  to 
  55°, 
  altogether 
  

   too 
  cool 
  for 
  them 
  to 
  have 
  risen 
  from 
  the 
  earth 
  to 
  recommence 
  their 
  flight 
  this 
  morning. 
  

   But, 
  on 
  the 
  other 
  side, 
  if 
  cold 
  renders 
  the 
  locust 
  sluggish, 
  how 
  does 
  it 
  succeed 
  in 
  keep- 
  

   ing 
  on 
  its 
  way 
  in 
  the 
  upper 
  strata 
  of 
  air, 
  which 
  are 
  much 
  colder 
  than 
  that 
  on 
  the 
  earth 
  ? 
  

   Does 
  its 
  action 
  develop 
  enough 
  heat 
  to 
  enable 
  it 
  to 
  keep 
  up 
  its 
  flight 
  ? 
  When 
  met 
  by 
  

   opposing 
  winds 
  I 
  have 
  seen 
  them 
  come 
  down 
  in 
  large 
  numbers, 
  but 
  by 
  common 
  con- 
  

   sent 
  to 
  descend 
  en 
  masse 
  I 
  have 
  no 
  knowledge 
  of 
  it. 
  I 
  see 
  no 
  way 
  to 
  avoid 
  the 
  conclu- 
  

   clusion 
  that 
  they 
  fly 
  all 
  night. 
  

  

  A. 
  L. 
  CHDLD, 
  M. 
  D. 
  

  

  