﻿434 
  F. 
  II. 
  Bigelow 
  — 
  International 
  Cloud 
  Work. 
  

  

  A 
  Standard 
  System 
  of 
  Constants 
  and 
  Forrnrdce. 
  

  

  Part 
  of 
  the 
  difficulty 
  in 
  making 
  students 
  generally 
  realize 
  

   that 
  meteorological 
  mathematics 
  already 
  stands 
  upon 
  a 
  definite 
  

   fundamental 
  basis 
  is 
  due 
  to 
  the 
  fact 
  that 
  while 
  many 
  papers 
  of 
  

   great 
  merit 
  exist, 
  they 
  are 
  detached 
  from 
  one 
  another, 
  and 
  

   there 
  is 
  no 
  well 
  defined 
  system 
  of 
  formulae 
  which 
  is 
  common 
  

   to 
  all 
  such 
  related 
  investigations. 
  Professor 
  Ferrel's 
  treatises, 
  

   it 
  is 
  true, 
  in 
  spite 
  of 
  his 
  inattention 
  to 
  a 
  consistent 
  and 
  clear 
  

   notation, 
  cover 
  the 
  ground, 
  as 
  he 
  conceived 
  the 
  solution 
  of 
  the 
  

   problem 
  in 
  a 
  consecutive 
  order 
  from 
  beginning 
  to 
  end. 
  Yet 
  

   many 
  of 
  his 
  primary 
  developments 
  are 
  exceedingly 
  complicated; 
  

   other 
  valuable 
  mathematical 
  analyses 
  have 
  been 
  discovered 
  

   since 
  his 
  day 
  ; 
  his 
  main 
  theory 
  of 
  the 
  local 
  cyclone 
  has 
  been 
  

   found 
  to 
  be 
  loaded 
  with 
  objections, 
  so 
  that 
  students 
  have 
  

   expected 
  that 
  before 
  long 
  improvements 
  would 
  be 
  introduced. 
  

   The 
  German 
  school 
  of 
  authors, 
  including 
  Guldberg 
  and 
  Mohn, 
  

   Oberbeck, 
  Sprung, 
  Hann 
  and 
  others, 
  have 
  followed 
  substan- 
  

   tially 
  one 
  line 
  of 
  thought 
  which 
  is 
  characteristic 
  of 
  them, 
  and 
  

   though 
  they 
  reach 
  many 
  results 
  in 
  agreement 
  with 
  Ferrel's, 
  

   especially 
  in 
  regard 
  to 
  the 
  general 
  cyclone 
  covering 
  a 
  hemi- 
  

   sphere 
  of 
  the 
  earth, 
  they 
  have 
  in 
  reality 
  radically 
  different 
  

   conceptions 
  regarding 
  the 
  structure 
  of 
  the 
  local 
  cyclone. 
  Thus, 
  

   in 
  Ferrel's 
  case, 
  it 
  was 
  assumed 
  that 
  the 
  general 
  and 
  the 
  local 
  

   cyclone 
  are 
  examples 
  of 
  the 
  same 
  type 
  of 
  circulation, 
  wherein 
  

   the 
  inner 
  and 
  the 
  outer 
  region 
  of 
  the 
  cyclone 
  are 
  separated 
  by 
  

   a 
  region 
  where 
  the 
  gyratory 
  velocity 
  about 
  the 
  central 
  axis 
  is 
  

   reduced 
  to 
  zero, 
  having 
  a 
  positive 
  direction 
  inside 
  and 
  a 
  nega- 
  

   tive 
  direction 
  outside 
  in 
  the 
  lower 
  strata, 
  with 
  a 
  complete 
  

   reversal 
  as 
  to 
  gradient 
  and 
  direction 
  in 
  the 
  upper 
  strata, 
  the 
  

   entire 
  system 
  embracing 
  the 
  same 
  fluid 
  material 
  in 
  a 
  continu- 
  

   ous 
  motion. 
  The 
  German 
  school, 
  on 
  the 
  other 
  hand, 
  began 
  

   with 
  the 
  principle 
  of 
  the 
  logarithmic 
  potential, 
  of 
  which 
  a 
  com- 
  

   mon 
  example 
  is 
  found 
  in 
  the 
  motion 
  of 
  tlie 
  ether 
  as 
  an 
  elec- 
  

   tric 
  current 
  through 
  a 
  wire 
  which 
  is 
  surrounded 
  by 
  a 
  magnetic 
  

   whirl. 
  In 
  this 
  case 
  there 
  is 
  no 
  reversal 
  of 
  the 
  direction 
  of 
  the 
  

   gyratory 
  motion, 
  but 
  instead 
  of 
  being 
  a 
  minimum 
  at 
  the 
  

   boundary 
  of 
  the 
  inner 
  and 
  the 
  outer 
  regions, 
  it 
  is 
  there 
  a 
  

   maximum. 
  The 
  inner 
  region 
  is 
  distinguished 
  from 
  the 
  outer, 
  

   however, 
  by 
  the 
  fact 
  that 
  it 
  alone 
  has 
  a 
  vertical 
  motion. 
  This 
  

   is 
  evidently 
  an 
  entirely 
  different 
  type 
  of 
  local 
  cyclone 
  from 
  

   Ferrel's. 
  In 
  the 
  case 
  of 
  the 
  general 
  cyclone 
  the 
  American 
  

   and 
  the 
  German 
  schools 
  are 
  in 
  much 
  closer 
  accord. 
  Further- 
  

   more, 
  some 
  important 
  difficulties 
  arose 
  from 
  the 
  attempt 
  to 
  

   account 
  for 
  the 
  energy 
  expended 
  in 
  the 
  local 
  cyclone, 
  on 
  the 
  

   theory 
  of 
  a 
  vertical 
  convection 
  due 
  to 
  the 
  buoyancy 
  of 
  air 
  

   expanded 
  by 
  the 
  liberation 
  of 
  latent 
  heat 
  in 
  large 
  quantities 
  

  

  