﻿Earth's 
  Penetrating 
  Radiation 
  with 
  Wulf 
  Electrometer. 
  747 
  

  

  Table 
  III. 
  

   Measurements 
  of 
  penetrating 
  radiation 
  at 
  Stations 
  on 
  Land. 
  

  

  Observation 
  Point. 
  

  

  ( 
  the 
  number 
  of 
  ions 
  pro- 
  

   duced 
  per 
  sec. 
  in 
  air 
  

   Values 
  of 
  " 
  q 
  " 
  = 
  \ 
  at 
  atmospheric 
  pres- 
  

   sure 
  by 
  the 
  penc- 
  

   il 
  trating 
  radiation. 
  

  

  Wulf 
  Electrometer. 
  Wilson 
  Electrometer. 
  

  

  Braunschweig, 
  Germany 
  , 
  

  

  Midlothian, 
  Scotland 
  

  

  Cambridge, 
  England, 
  I. 
  ...... 
  

  

  II 
  

  

  The 
  Physical 
  Laboratory, 
  

   Toronto 
  

  

  8-1 
  

   90 
  

  

  826 
  

  

  862 
  

  

  8 
  ; 
  i 
  

  

  9-47 
  

   ) 
  12-0 
  

  

  to 
  

   J 
  14 
  S 
  

  

  8-84 
  

   8-67 
  

  

  6 
  83 
  

   4-93 
  

  

  4-77 
  

   4-33 
  

  

  8 
  : 
  32 
  

   903 
  

  

  9 
  0S 
  

  

  8'8S 
  

  

  4-46 
  

   6-03 
  

  

  The 
  Meteorological 
  Observa- 
  

  

  The 
  University 
  Lawn 
  

  

  In 
  a 
  residence 
  in 
  Toronto 
  

   made 
  of 
  red 
  brick 
  

  

  In 
  a 
  deep 
  pit 
  in 
  the 
  Lorraine 
  

   Shale 
  in 
  a 
  brick-yard 
  at 
  

   Toronto 
  

  

  Close 
  to 
  walls 
  of 
  glacial 
  clay 
  

   deposits 
  

  

  On 
  layer 
  of 
  sand 
  and 
  clay, 
  

   2*5 
  metres 
  thick, 
  above 
  pit 
  

   of 
  shale 
  

  

  On 
  surface 
  - 
  layer 
  of 
  sandy 
  

   loam 
  about 
  33 
  metres 
  from 
  

   entrance 
  to 
  opening 
  in 
  clay 
  

  

  On 
  the 
  surface 
  of 
  Lake 
  Ontario 
  

   Eight 
  metres 
  under 
  the 
  sur- 
  

   face 
  of 
  Lake 
  Ontario 
  at 
  a 
  

   point 
  where 
  it 
  was 
  twenty 
  

  

  metres 
  deep 
  

  

  Mean 
  of 
  measurements 
  taken 
  

   on 
  the 
  Ocean 
  

  

  high 
  value 
  obtained 
  for 
  the 
  ionization 
  on 
  the 
  ocean 
  with 
  

   the 
  Wilson 
  electrometer, 
  goes 
  to 
  show, 
  as 
  one 
  might 
  have 
  

   anticipated, 
  that 
  it 
  is 
  quite 
  impossible 
  to 
  take 
  readings 
  on 
  

   ship-board 
  with 
  an 
  instrument 
  provided 
  with 
  a 
  gold-leaf 
  

   system 
  with 
  any 
  degree 
  of 
  accurac) 
  r 
  . 
  

  

  In 
  the 
  course 
  of 
  the 
  observation 
  at 
  Toronto 
  values 
  between 
  

   9 
  and 
  10 
  ions 
  per 
  c.c. 
  per 
  sec, 
  with 
  a 
  mean 
  of 
  9'47, 
  were 
  

   obtained 
  when 
  the 
  readings 
  were 
  taken 
  in 
  a 
  residential 
  

   building 
  the 
  walls 
  of 
  which 
  were 
  constructed 
  of 
  red 
  brick. 
  

  

  As 
  values 
  close 
  to 
  8'62 
  for 
  "q 
  n 
  were 
  always 
  obtained 
  in 
  

  

  