﻿604 
  Prof. 
  L. 
  V. 
  King 
  on 
  the 
  Gradient 
  of 
  the 
  

  

  The 
  results 
  obtained 
  from 
  sixteen 
  determinations 
  are 
  given 
  

   in 
  the 
  following 
  table: 
  — 
  

  

  Current, 
  

   amps. 
  

  

  E 
  x 
  -E 
  2 
  . 
  

   volts. 
  

  

  Deflexion, 
  

   mms. 
  

  

  e 
  x 
  -e 
  2 
  . 
  

  

  V 
  

  

  Mean 
  

   Temp. 
  9. 
  

  

  £X10 
  G 
  . 
  

  

  3-49 
  

  

  •980 
  

  

  59-7 
  

  

  4-92 
  

  

  16-20 
  

  

  18-7 
  

  

  2268 
  

  

  3-96 
  

  

  1122 
  

  

  77-7 
  

  

  6-41 
  

  

  1620 
  

  

  19-4 
  

  

  2264 
  

  

  4-49 
  

  

  1-261 
  

  

  98-4 
  

  

  8-12 
  

  

  16-20 
  

  

  203 
  

  

  2278 
  

  

  4-88 
  

  

  1-365 
  

  

  116-8 
  

  

  9-64 
  

  

  16-20 
  

  

  21-0 
  

  

  2258 
  

  

  3-49 
  

  

  •970 
  

  

  58-8 
  

  

  4-85 
  

  

  1587 
  

  

  18-3 
  

  

  2279 
  

  

  3-96 
  

  

  1-109 
  

  

  78-0 
  

  

  6-43 
  

  

  15-90 
  

  

  191 
  

  

  2228 
  

  

  449 
  

  

  1-246 
  

  

  99-5 
  

  

  8-21 
  

  

  1590 
  

  

  200 
  

  

  2226 
  

  

  4-98 
  

  

  1-380 
  

  

  122-5 
  

  

  1010 
  

  

  15-92 
  

  

  210 
  

  

  2221 
  

  

  3-49 
  

  

  •970 
  

  

  58-6 
  

  

  4-83 
  

  

  15-60 
  

  

  18-0 
  

  

  2286 
  

  

  3-96 
  

  

  1105 
  

  

  771 
  

  

  636 
  

  

  15-65 
  

  

  18-8 
  

  

  2246 
  

  

  4-49 
  

  

  1-244 
  

  

  98-3 
  

  

  8-11 
  

  

  15-75 
  

  

  19-8 
  

  

  2249 
  

  

  4-98 
  

  

  1-380 
  

   •968 
  

  

  1223 
  

  

  10-09 
  

  

  15-70 
  

  

  207 
  

  

  2225 
  

  

  349 
  

  

  58-7 
  

  

  4-84 
  

  

  1570 
  

  

  18-1 
  

  

  2279 
  

  

  396 
  

  

  1103 
  

  

  78-0 
  

  

  6-43 
  

  

  15-70 
  

  

  189 
  

  

  2216 
  

  

  4-49 
  

  

  1-244 
  

  

  97-7 
  

  

  8-06 
  

  

  1572 
  

  

  19-7 
  

  

  2264 
  

  

  4-98 
  

  

  1-380 
  

  

  122-3 
  

  

  10-09 
  

  

  15-70 
  

  

  20-7 
  

  

  2225 
  

  

  Mean 
  value 
  of 
  & 
  = 
  -00225. 
  

  

  § 
  7. 
  Temperature 
  Coefficient 
  of 
  h. 
  

  

  The 
  preliminary 
  experiments 
  which 
  have 
  already 
  been 
  

   made 
  on 
  the 
  temperature 
  coefficient 
  of 
  k 
  indicate 
  that 
  the 
  

   method 
  is 
  quite 
  satisfactory 
  for 
  making 
  accurate 
  determi- 
  

   nations 
  of 
  this 
  quantify. 
  Experiments 
  are 
  now 
  being 
  made 
  

   on 
  glass 
  and 
  quartz. 
  

  

  Physical 
  Laboratory, 
  

   University 
  of 
  Bristol, 
  

   June 
  1913. 
  

  

  L. 
  On 
  the 
  Gradient 
  of 
  the 
  Penetrating 
  Radiation 
  from 
  the 
  

   Earth. 
  By 
  Louis 
  V. 
  King, 
  B.A., 
  Assist. 
  Professor 
  of 
  

   Physics, 
  McGill 
  University, 
  Montreal*. 
  

  

  Sect. 
  1. 
  Introduction. 
  

  

  IT 
  was 
  first 
  shown 
  by 
  Eve 
  f 
  that, 
  if 
  the 
  penetrating 
  radia- 
  

   tion 
  is 
  due 
  to 
  7-rays 
  from 
  the 
  radio-active 
  constituents 
  

   of 
  the 
  soil, 
  the 
  intensity 
  should 
  decrease 
  rapidly 
  with 
  height 
  

   above 
  the 
  earth's 
  surface 
  and 
  should 
  be 
  easily 
  measurable. 
  

  

  * 
  Communicated 
  by 
  Prof. 
  A. 
  S. 
  Eve. 
  

  

  t 
  Eve, 
  Phil. 
  Mag. 
  xxi. 
  Jan. 
  1911, 
  pp. 
  26-46. 
  

  

  