﻿324 
  0. 
  L. 
  Fassig 
  — 
  March 
  Weather 
  in 
  the 
  United 
  States. 
  

  

  Hildebrandsson* 
  finds 
  that 
  the 
  barometric 
  variations 
  abont 
  

   the 
  Azores 
  and 
  about 
  Iceland 
  are 
  nearly 
  always 
  opposed. 
  

   That 
  the 
  same 
  is 
  true 
  of 
  the 
  variations 
  in 
  Siberia 
  and 
  Alaska. 
  

   That 
  there 
  exists 
  a 
  sort 
  of 
  oscillation 
  in 
  the 
  pressure 
  of 
  the 
  air 
  

   between 
  a 
  center 
  of 
  action 
  of 
  high 
  pressure 
  and 
  another 
  neigh- 
  

   boring 
  one 
  of 
  low 
  pressure. 
  In 
  comparing, 
  on 
  the 
  other 
  hand, 
  

   the 
  curves 
  for 
  the 
  Azores 
  and 
  for 
  Siberia, 
  he 
  finds 
  a 
  remark- 
  

   able 
  agreement. 
  The 
  variations 
  at 
  Key 
  West 
  do 
  not 
  accord 
  

   with 
  those 
  in 
  the 
  Azores, 
  but 
  are 
  in 
  accord 
  with 
  those 
  at 
  San 
  

   Diego. 
  The 
  departures 
  of 
  the 
  same 
  sign 
  nearly 
  always 
  cover 
  

   very 
  large 
  areas. 
  

  

  According 
  to 
  Major 
  Ilawson,f 
  the 
  so 
  called 
  permanent 
  areas 
  

   of 
  high 
  pressure 
  in 
  the 
  northern 
  hemisphere 
  do 
  not 
  have 
  a 
  

   steady 
  progressive 
  movement, 
  but 
  shift 
  to 
  one 
  side 
  or 
  another 
  

   about 
  a 
  fairly 
  well-defined 
  average 
  position. 
  

  

  Poincare:}: 
  has 
  in 
  recent 
  years 
  presented 
  to 
  the 
  French 
  

   Academy 
  of 
  Sciences 
  many 
  communications 
  upon 
  the 
  probable 
  

   cause 
  of 
  these 
  anomalous 
  pressure 
  changes, 
  attributing 
  them 
  to 
  

   the 
  influence 
  of 
  the 
  moon. 
  

  

  Thus 
  we 
  see 
  that 
  there 
  is 
  abundant 
  testimony 
  to 
  establish 
  

   the 
  existence 
  of 
  well-defined 
  larger 
  movements 
  of 
  the 
  atmos- 
  

   phere, 
  w^iich 
  differ 
  in 
  extent 
  and 
  character 
  of 
  movement 
  from 
  

   the 
  transient 
  high 
  and 
  low 
  areas 
  pictured 
  upon 
  our 
  daily 
  

   weather 
  maps; 
  also 
  that 
  these 
  movements 
  have 
  a 
  direct 
  and 
  

   important 
  bearing 
  upon 
  local 
  climate. 
  Leaving 
  the 
  Jiistorical 
  

   side 
  of 
  the 
  question, 
  we 
  come 
  to 
  the 
  consideration 
  of 
  the 
  posi- 
  

   tions 
  occupied 
  by 
  these 
  persistent 
  areas 
  of 
  high 
  and 
  low 
  pres- 
  

   sure 
  during 
  March, 
  and 
  their 
  influence 
  upon 
  local 
  climates 
  in 
  

   the 
  United 
  States. 
  

  

  Average 
  weather 
  conditions 
  during 
  March. 
  — 
  In 
  a 
  study 
  of 
  

   weather 
  conditions 
  it 
  is 
  essential 
  to 
  bear 
  in 
  mind 
  the 
  " 
  law 
  of 
  

   winds" 
  announced 
  independently 
  over 
  fifty 
  years 
  ago 
  by 
  our 
  

   own 
  countryman 
  William 
  Ferrel, 
  and 
  by 
  Buys-Ballot 
  of 
  Hol- 
  

   land 
  : 
  where 
  there 
  is 
  a 
  difference 
  of 
  pressure 
  between 
  neighbor- 
  

   ing 
  regions 
  on 
  the 
  same 
  level 
  the 
  air 
  will 
  flow 
  out 
  of 
  the 
  

   region 
  of 
  high 
  pressure 
  into 
  the 
  region 
  of 
  low 
  pressure. 
  

   Owing 
  to 
  the 
  revolution 
  of 
  the 
  earth 
  about 
  its 
  axis 
  the 
  flow 
  of 
  

   air 
  will 
  not 
  be 
  along 
  straight 
  lines, 
  but 
  along 
  lines 
  constantly 
  

   bending 
  to 
  the 
  right 
  of 
  the 
  initial 
  direction 
  in 
  the 
  northern 
  

   hemisphere; 
  to 
  the 
  left 
  in 
  the 
  southern 
  hemisphere. 
  The 
  

   daily 
  weather 
  chart 
  issued 
  by 
  the 
  United 
  States 
  Weather 
  

   Bureau 
  has 
  made 
  us 
  familiar 
  wnth 
  such 
  systems 
  of 
  wind 
  circu- 
  

   lation 
  as 
  they 
  pass 
  across 
  the 
  country 
  every 
  few 
  days, 
  and 
  has 
  

  

  * 
  Quelques 
  recherches 
  sur 
  les 
  centres 
  d'acfciou 
  de 
  ratmosphe'e. 
  Stockholm. 
  

   1897. 
  

  

  f 
  Anticyclouic 
  sj'stems 
  and 
  their 
  movemeuts, 
  Quart. 
  Jouru. 
  Met. 
  Soc 
  , 
  Loudon, 
  

   vol. 
  xxiv. 
  1898. 
  

  

  JSee 
  Compt. 
  Roud, 
  Acad. 
  Sci., 
  Paris, 
  1889 
  et 
  scq. 
  

  

  