﻿630 
  Prof. 
  A. 
  S. 
  Eve 
  on 
  the 
  Amount 
  of 
  Radium 
  

  

  The 
  best 
  examples 
  of 
  cyclone 
  effects 
  were 
  

  

  9 
  Dec. 
  1907. 
  

  

  108? 
  

  

  grm. 
  x 
  10~ 
  12 
  

  

  23 
  

  

  198? 
  

  

  J 
  3 
  

  

  23 
  Jan. 
  1908. 
  

  

  102 
  

  

  53 
  

  

  27 
  April 
  „ 
  

  

  93 
  

  

  33 
  

  

  and 
  of 
  anticyclones 
  

  

  

  

  20 
  Dec. 
  1907. 
  

  

  31 
  

  

  grm. 
  x 
  10~ 
  12 
  

  

  20 
  Jan. 
  1908. 
  

  

  25 
  

  

  3? 
  

  

  30 
  Jan. 
  „ 
  

  

  15 
  

  

  y> 
  

  

  10 
  March,, 
  

  

  19 
  

  

  ■>-> 
  

  

  On 
  30th 
  January 
  the 
  barometer 
  rose 
  to 
  30*5, 
  and 
  the* 
  

   thermometer 
  fell 
  to 
  20° 
  below 
  zero, 
  Fahr. 
  The 
  natural 
  leak 
  

   of 
  the 
  electroscope, 
  and 
  the 
  " 
  rest 
  " 
  experiments, 
  were 
  not 
  

   affected 
  by 
  the 
  changes 
  of 
  weather, 
  as 
  the 
  laboratory 
  was 
  

   dry 
  and 
  at 
  a 
  steady 
  temperature. 
  

  

  The 
  reading 
  of 
  23rd 
  December 
  was 
  nearly 
  twice 
  as 
  great 
  

   as 
  any 
  other, 
  and 
  may 
  perhaps 
  have 
  been 
  incorrect. 
  Ex- 
  

   cepting 
  this, 
  the 
  ratio 
  of 
  the 
  greatest 
  to 
  the 
  least 
  values 
  was 
  

   7 
  to 
  1, 
  and 
  this 
  is 
  less 
  than 
  the 
  corresponding 
  ratio 
  16 
  to 
  1, 
  

   found 
  by 
  Elster 
  and 
  Greitel 
  in 
  the 
  case 
  of 
  the 
  active 
  deposit 
  

   collected 
  from 
  the 
  atmosphere 
  by 
  a 
  negatively 
  charged 
  wire. 
  

   The 
  variations 
  in 
  the 
  amount 
  of 
  active 
  deposit 
  are 
  modified 
  

   by 
  the 
  influence 
  of 
  smoke, 
  dust, 
  and 
  mist 
  — 
  disturbing 
  factors 
  

   which 
  are 
  avoided 
  in 
  measurement 
  of 
  the 
  emanation. 
  

  

  There 
  are 
  many 
  reasons 
  why 
  the 
  amount 
  of 
  radium 
  ema- 
  

   nation 
  in 
  the 
  atmosphere 
  should 
  be 
  increased 
  when 
  a 
  cyclone 
  

   prevails, 
  for 
  then 
  : 
  — 
  

  

  (1) 
  The 
  air 
  is 
  moving 
  along 
  the 
  surface 
  of 
  the 
  earth 
  in 
  

  

  large 
  spiral 
  paths 
  towards 
  the 
  centre 
  of 
  the 
  depres- 
  

   sion 
  where 
  the 
  air 
  rises. 
  Thus 
  the 
  air 
  near 
  the 
  

   earth's 
  surface 
  contains 
  much 
  of 
  the 
  emanation 
  

   escaping 
  from 
  the 
  ground. 
  But 
  with 
  an 
  anticyclone, 
  

   air 
  is 
  descending 
  from 
  altitudes 
  where 
  the 
  contained 
  

   emanation 
  has 
  decayed, 
  and 
  where 
  fresh 
  supplies 
  are 
  

   not 
  forthcoming. 
  

  

  (2) 
  Diminishing 
  pressure 
  causes 
  radium 
  emanation, 
  with 
  

  

  other 
  gases, 
  to 
  pass 
  out 
  from 
  the 
  ground 
  into 
  the 
  

   atmosphere. 
  

  

  (3) 
  Rain 
  usually 
  accompanies 
  a 
  cyclone, 
  and 
  in 
  winter 
  

  

  higher 
  temperatures 
  prevail 
  and 
  cause 
  the 
  snow 
  to 
  

   melt. 
  In 
  both 
  cases 
  water 
  enters 
  and 
  moistens 
  the 
  

   soil, 
  and 
  emanation 
  escapes 
  more 
  readily 
  from 
  radium 
  

   salts 
  when 
  these 
  are 
  moist 
  or 
  in 
  solution. 
  

  

  After 
  experimenting 
  for 
  some 
  months 
  it 
  was 
  found 
  possible 
  

  

  