﻿432 
  F. 
  Waldo 
  — 
  Wind 
  Velocities 
  in 
  the 
  United 
  States. 
  

  

  tigation 
  and 
  so 
  I 
  have 
  arranged 
  the 
  data 
  for 
  the 
  four 
  mid- 
  

   seasonal 
  months 
  and 
  for 
  the 
  year, 
  according 
  to 
  the 
  local 
  times 
  ; 
  

   and, 
  moreover, 
  have 
  converted 
  the 
  published 
  anemometer 
  miles 
  

   (with 
  constant 
  3*00) 
  into 
  true 
  miles 
  by 
  means 
  of 
  Marvin's 
  

   Table 
  published 
  by 
  the 
  Signal 
  Service. 
  I 
  have 
  also 
  grouped 
  

   the 
  stations 
  geographically 
  and 
  not 
  alphabetically 
  as 
  given 
  in 
  

   the 
  original 
  table 
  of 
  hourly 
  winds. 
  This 
  table 
  cannot 
  be 
  

   reproduced 
  here 
  on 
  account 
  of 
  its 
  length, 
  but 
  I 
  may 
  remark 
  

   that 
  the 
  relations 
  of 
  the 
  maxima 
  and 
  minima 
  have 
  been 
  inves- 
  

   tigated 
  ; 
  and 
  in 
  the 
  unpublished 
  table 
  are 
  given 
  the 
  amplitudes 
  

   or 
  ranges 
  in 
  miles 
  per 
  hour, 
  the 
  excesses 
  and 
  deficiencies 
  in 
  

   terms 
  of 
  the 
  average, 
  and 
  the 
  amplitudes 
  in 
  terms 
  of 
  percent- 
  

   age 
  of 
  the 
  averages. 
  An 
  account 
  of 
  this 
  will 
  shortly 
  appear 
  

   in 
  the 
  American 
  Meteorological 
  Journal. 
  

  

  The 
  curves 
  showing 
  the 
  daily 
  march 
  of 
  the 
  hourly 
  wind 
  

   velocities 
  for 
  January, 
  July 
  and 
  the 
  Year, 
  I 
  have 
  also 
  drawn 
  

   for 
  individual 
  stations, 
  but 
  these 
  cannot 
  be 
  reproduced 
  here 
  on 
  

   account 
  of 
  the 
  expense 
  of 
  drawings. 
  The 
  characteristics 
  of 
  

   these 
  curves 
  show 
  marked 
  variations 
  with 
  changes 
  of 
  geo- 
  

   graphical 
  position, 
  as 
  we 
  should 
  expect 
  : 
  and 
  while 
  the 
  num- 
  

   ber 
  of 
  years 
  of 
  observations 
  which 
  have 
  been 
  employed, 
  

   which 
  for 
  the 
  most 
  cases 
  is 
  T, 
  is 
  not 
  sufficient 
  to 
  remove 
  all 
  

   irregularities 
  from 
  some 
  of 
  the 
  curves, 
  yet 
  in 
  most 
  cases 
  a 
  suf- 
  

   ficiently 
  good 
  idea 
  of 
  the 
  daily 
  march 
  is 
  given. 
  I 
  have 
  how- 
  

   ever 
  given 
  the 
  curves 
  for 
  January 
  and 
  July 
  for 
  20 
  stations 
  

   more 
  or 
  less 
  representative 
  of 
  the 
  various 
  sections 
  of 
  the 
  U. 
  S. 
  

   See 
  the 
  curves 
  and 
  explanation 
  of 
  the 
  diagram 
  at 
  the 
  end 
  of 
  

   this 
  paper. 
  This 
  material 
  is 
  of 
  such 
  importance 
  that 
  the 
  curves 
  

   deserve 
  to 
  be 
  taken 
  up 
  for 
  discussion 
  for 
  individual 
  stations, 
  but 
  

   it 
  is 
  only 
  possible, 
  in 
  the 
  present 
  instance, 
  to 
  treat 
  them 
  in 
  

   groups. 
  Without 
  further 
  preliminary 
  remarks 
  I 
  will 
  give 
  the 
  

   main 
  characteristics 
  of 
  these 
  curves 
  in 
  what 
  seems 
  to 
  me 
  to 
  be 
  a 
  

   proper 
  order. 
  In 
  counting 
  the 
  hours, 
  midnight 
  is 
  given 
  as 
  h 
  . 
  

   The 
  wind 
  velocities 
  are 
  given 
  in 
  miles 
  per 
  hour 
  : 
  written 
  

   m. 
  p. 
  h. 
  In 
  mentioning 
  the 
  characteristics 
  of 
  these 
  curves, 
  it 
  

   will 
  be 
  remembered 
  that 
  a 
  sharp 
  ascent 
  or 
  descent 
  indicates 
  a 
  

   rapid 
  change 
  in 
  the 
  wind 
  velocity 
  from 
  hour 
  to 
  hour 
  ; 
  aflat 
  

   curve 
  indicates 
  no 
  change 
  ; 
  a 
  sharp 
  crest 
  or 
  trough 
  shows 
  an 
  

   extreme 
  maximum 
  or 
  minimum 
  of 
  short 
  duration, 
  while 
  when 
  

   well 
  rounded 
  they 
  indicate 
  a 
  period 
  of 
  several 
  hours 
  during 
  

   which 
  the 
  conditions 
  at 
  these 
  phases 
  continue 
  to 
  prevail 
  before 
  

   the 
  swing 
  to 
  the 
  opposite 
  phase 
  sets 
  in. 
  

  

  Atlantic 
  Coast. 
  — 
  On 
  the 
  exposed 
  Atlantic 
  Coast 
  (Curve 
  1) 
  

   there 
  is 
  in 
  January 
  but 
  a 
  slight 
  variation 
  in 
  the 
  wind 
  velocity 
  

   from 
  hour 
  to 
  hour 
  during 
  the 
  whole 
  day, 
  the 
  average 
  wind 
  

   being 
  15 
  or 
  16 
  m. 
  p. 
  h. 
  ; 
  but 
  for 
  July 
  there 
  is 
  a 
  strongly 
  

   defined 
  maximum 
  (12 
  or 
  13 
  m. 
  p. 
  h.) 
  at 
  about 
  16 
  h 
  , 
  and 
  a 
  mini- 
  

  

  