﻿INFLUENCE 
  OF 
  THE 
  RAINFALL 
  ON 
  THE 
  LOCUST. 
  113 
  

  

  especially 
  in 
  Nebraska, 
  Iowa, 
  Minnesota 
  and 
  Manitoba. 
  This 
  was 
  also 
  

   a 
  year 
  of 
  visitation 
  in 
  Utah, 
  Montana, 
  parts 
  of 
  Dakota, 
  Colorado, 
  and 
  

   the 
  northern 
  portion 
  of 
  New 
  Mexico. 
  But 
  in 
  numbers 
  and 
  general 
  dis- 
  

   tribution 
  in 
  the 
  region 
  east 
  of 
  the 
  mountains, 
  it 
  was 
  far 
  exceeded 
  by 
  the 
  

   locnst 
  invasion 
  of 
  1866; 
  in 
  fact 
  it 
  is 
  not 
  usually 
  counted 
  as 
  one 
  of 
  the 
  

   great 
  locust 
  years. 
  

  

  Before 
  passing 
  to 
  other 
  points 
  suggested 
  by 
  this 
  table 
  we 
  desire 
  to 
  

   present 
  other 
  evidence 
  showing 
  the 
  unusually 
  favorable 
  conditions 
  of 
  

   this 
  year 
  for 
  the 
  increase 
  and 
  spread 
  of 
  the 
  locusts 
  so 
  far 
  as 
  dryness 
  

   is 
  concerned. 
  

  

  First 
  we 
  call 
  attention 
  to 
  the 
  fact 
  that 
  there 
  had 
  been 
  a 
  gradual 
  

   decrease 
  in 
  the 
  rainfall 
  the 
  two 
  preceding 
  years, 
  as 
  will 
  be 
  seen 
  by 
  refer- 
  

   ence 
  to 
  the 
  column 
  of 
  means. 
  In 
  1862 
  the 
  mean 
  of 
  all 
  the 
  stations 
  was 
  

   .95 
  ; 
  in 
  1863 
  it 
  was 
  .87, 
  falling 
  in 
  1864 
  to 
  .73. 
  

  

  Does 
  the 
  character 
  of 
  1864, 
  as 
  shown 
  by 
  these 
  figures, 
  correspond 
  

   with 
  that 
  of 
  the 
  year 
  throughout 
  the 
  West 
  % 
  By 
  reference 
  to 
  Schotfs 
  

   tables, 
  we 
  find 
  these 
  ratios 
  given 
  for 
  that 
  year 
  in 
  the 
  following 
  States 
  and 
  

   Territories. 
  The 
  names 
  of 
  the 
  stations 
  are 
  not 
  mentioned 
  here, 
  as 
  our 
  

   object 
  is 
  only 
  to 
  show 
  the 
  general 
  character 
  of 
  the 
  season 
  in 
  reference 
  

   to 
  humidity, 
  as 
  compared 
  with 
  the 
  mean 
  annual 
  rainfall. 
  Each 
  ratio 
  

   represents 
  the 
  rainfall 
  of 
  a 
  station 
  for 
  1864, 
  in 
  the 
  same 
  manner 
  as 
  given 
  

   in 
  the 
  foregoing 
  tables 
  : 
  

  

  Texas, 
  .81. 
  

  

  Tennessee, 
  .89. 
  

  

  Kansas, 
  .51, 
  .51, 
  .66. 
  

  

  Kentucky, 
  .93. 
  

  

  New 
  Mexico, 
  .76, 
  1.25. 
  

  

  Ohio, 
  .96, 
  1.19, 
  .74, 
  .96. 
  

  

  California, 
  .99, 
  .81, 
  .91, 
  .86 
  

  

  Michigan, 
  .86. 
  

  

  Washington 
  Ter., 
  .81, 
  .69. 
  

  

  Indiana, 
  .79, 
  .87. 
  

  

  Oregon, 
  .91, 
  78. 
  

  

  Illinois, 
  .79, 
  .83. 
  

  

  Idaho, 
  .82. 
  

  

  Wisconsin, 
  .98. 
  

  

  Utah, 
  1.00, 
  1.20. 
  

  

  Minnesota, 
  .48, 
  .56, 
  .75, 
  .61. 
  

  

  Dakota, 
  .87. 
  

  

  Iowa, 
  .74, 
  .86, 
  .75. 
  

  

  Nebraska, 
  .70. 
  

  

  Missouri, 
  .79, 
  .87, 
  .96, 
  .94. 
  

  

  The 
  general 
  average 
  of 
  these 
  ratios 
  is 
  .83, 
  or 
  17 
  per 
  cent, 
  less 
  than 
  the 
  

   usual 
  rainfall 
  throughout 
  the 
  entire 
  West; 
  and 
  what 
  is 
  rather 
  unusual, 
  

   and 
  indicative 
  of 
  the 
  general 
  prevalence 
  of 
  the 
  dry 
  season 
  over 
  the 
  en- 
  

   tire 
  western 
  portion 
  of 
  the 
  United 
  States, 
  is 
  that, 
  with 
  the 
  exception 
  of 
  

   one 
  station 
  in 
  Ohio, 
  one 
  in 
  New 
  Mexico," 
  which 
  is 
  estimated, 
  and 
  the 
  two 
  

   in 
  Utah, 
  the 
  records 
  all 
  show 
  less 
  than 
  the 
  average 
  precipitation. 
  So 
  

   far, 
  therefore, 
  as 
  the 
  amount 
  of 
  moisture 
  is 
  concerned, 
  this 
  was 
  evidently 
  

   a 
  favorable 
  year 
  for 
  the 
  locusts. 
  

  

  Xow 
  let 
  us 
  turn 
  to 
  the 
  record 
  of 
  temperature 
  and 
  see 
  whether 
  that 
  

   was 
  favorable 
  or 
  unfavorable. 
  For 
  this 
  we 
  have 
  recourse 
  to 
  the 
  re- 
  

   ports 
  of 
  the 
  Agricultural 
  Department 
  as 
  the 
  only 
  data 
  at 
  hand 
  adapted 
  

   to 
  our 
  purpose. 
  As 
  our 
  object 
  is 
  to 
  compare 
  the 
  meteorology 
  of 
  1864 
  

   with 
  that 
  of 
  1866, 
  we 
  present, 
  in 
  the 
  following 
  table, 
  in 
  parallel 
  columns, 
  

   the 
  record 
  of 
  monthly 
  means 
  of 
  temperature 
  of 
  the 
  two 
  years 
  in 
  Minne- 
  

   sota, 
  Iowa, 
  Nebraska, 
  Kansas, 
  and 
  Missouri. 
  

   8l 
  

  

  