﻿230 
  Mr. 
  R. 
  M. 
  Deeley 
  on 
  

  

  process 
  which 
  may 
  be 
  looked 
  upon 
  as 
  a 
  primary 
  meteoro- 
  

   logical 
  law, 
  the 
  results 
  o£ 
  which 
  are 
  more 
  and 
  more 
  apparent 
  

   as 
  the 
  conditions 
  are 
  more 
  and 
  more 
  free 
  from 
  disturbing 
  

   causes, 
  mechanical 
  or 
  meteorological." 
  

  

  It 
  was 
  previously 
  suggested 
  that 
  the 
  surface 
  winds 
  often 
  

   followed 
  directions 
  resembling 
  the 
  eccentric 
  paths 
  of 
  comets. 
  

   Their 
  courses, 
  however, 
  at 
  higher 
  levels 
  more 
  closely 
  resemble 
  

   planetary 
  orbits. 
  In 
  the 
  last 
  paragraph 
  of 
  the 
  preface 
  to 
  

   Gold's 
  paper 
  Shaw 
  remarks: 
  "The 
  whole 
  question 
  of 
  the 
  

   cause 
  and 
  meaning 
  of 
  the 
  discrepancies 
  between 
  the 
  gradient 
  

   wind 
  and 
  the 
  actual 
  wind 
  is, 
  of 
  course, 
  bound 
  up 
  with 
  the 
  

   origin 
  of 
  pressure 
  differences. 
  To 
  put 
  the 
  point 
  in 
  a 
  crude 
  

   form, 
  I 
  do 
  not 
  know 
  whether, 
  in 
  practice, 
  the 
  winds 
  have 
  to 
  

   adjust 
  themselves 
  to 
  the 
  pressure 
  conditions, 
  or 
  the 
  pressure 
  

   distribution 
  is 
  the 
  result 
  of 
  the 
  motion 
  of 
  the 
  air." 
  

  

  Perhaps 
  the 
  most 
  promising 
  way 
  of 
  ascertaining 
  the 
  

   cause 
  of 
  the 
  circulation 
  of 
  the 
  winds 
  is 
  to 
  be 
  found 
  by 
  

   studying 
  the 
  distribution 
  of 
  atmospheric 
  temperatures. 
  In 
  

   this 
  direction 
  a 
  great 
  deal 
  has 
  been 
  done 
  in 
  the 
  exploration 
  

   of 
  the 
  upper 
  atmosphere 
  by 
  means 
  of 
  pilot 
  balloons. 
  In 
  this 
  

   connexion 
  we 
  cannot 
  do 
  better 
  than 
  consult 
  a 
  paper 
  by 
  Shaw 
  

   and 
  Dines* 
  on 
  " 
  The 
  Free 
  Atmosphere 
  in 
  the 
  Region 
  of 
  the 
  

   British 
  Isles." 
  

  

  Fig. 
  6 
  is 
  a 
  diagram 
  showing 
  the 
  distribution 
  of 
  temperature 
  

   within 
  a 
  cyclone 
  2000 
  miles 
  in 
  diameter. 
  It 
  will 
  be 
  noticed 
  

   that 
  the 
  temperatures 
  below 
  about 
  10 
  kilometres 
  are 
  lower 
  in 
  

   the 
  centre 
  than 
  in 
  the 
  margin 
  of 
  the 
  depression. 
  It 
  is 
  clear, 
  

   therefore, 
  that 
  the 
  temperature 
  distribution 
  below 
  this 
  level 
  

   is 
  such 
  as 
  w 
  r 
  ould 
  cause 
  a 
  descent 
  of 
  air 
  at 
  the 
  cyclonic 
  centre. 
  

   The 
  old 
  theory 
  that 
  a 
  cyclone 
  results 
  from 
  the 
  ascent 
  of 
  warm 
  

   air 
  from 
  the 
  earth's 
  surface 
  must 
  be 
  abandoned. 
  

  

  The 
  dotted 
  line 
  B 
  B 
  shows 
  the 
  dividing 
  line 
  between 
  the 
  

   Stratosphere 
  and 
  Troposphere. 
  In 
  the 
  stratosphere 
  the 
  

   temperature 
  not 
  only 
  rises 
  as 
  the 
  height 
  increases, 
  but 
  over 
  

   the 
  cyclone 
  there 
  is 
  a 
  local 
  mass 
  of 
  heated 
  air. 
  I 
  would 
  

   suggest 
  that 
  this 
  heated 
  air 
  extends 
  to 
  the 
  confines 
  of 
  the 
  

   atmosphere, 
  and 
  there 
  is 
  there 
  formed 
  a 
  gravity 
  gradient 
  

   for 
  the 
  flow 
  of 
  air 
  outwards. 
  The 
  displacement 
  of 
  this 
  air 
  

   reduces 
  the 
  weight 
  of 
  the 
  air 
  column, 
  and 
  the 
  result 
  is 
  felt 
  

   at 
  the 
  earth's 
  surface. 
  

  

  Instead 
  of 
  the 
  air 
  moving 
  into 
  and 
  filling 
  up 
  the 
  low-pressure 
  

   area 
  at 
  once, 
  it 
  circulates 
  round 
  it, 
  in 
  a 
  manner 
  depending 
  

   upon 
  the 
  direction 
  of 
  the 
  air-currents 
  in 
  the 
  atmosphere 
  at 
  

  

  * 
  Meteorological 
  Office 
  Report, 
  No. 
  210 
  b. 
  

  

  