﻿Intelliyence 
  and 
  Miscellaneous 
  Articles. 
  937 
  

  

  AVhile 
  accepting 
  the 
  view 
  that 
  frozen 
  conditions 
  in 
  former 
  times 
  

   altered 
  the 
  drainage-system 
  of 
  the 
  Chalk, 
  he 
  argues 
  that 
  the 
  most 
  

   potent 
  excavating 
  force 
  was 
  the 
  frost 
  itself 
  acting 
  on 
  Chalk 
  saturated 
  

   or 
  highly 
  charged 
  with 
  water. 
  He 
  propounds 
  a 
  theory 
  to 
  account 
  

   for 
  (1) 
  the 
  great 
  size 
  and 
  breadth 
  of 
  the 
  valleys 
  in 
  relation 
  to 
  their 
  

   catchment-basins 
  ; 
  (2) 
  the 
  ramifications 
  of 
  some 
  of 
  the 
  valley- 
  

   systems 
  ; 
  and 
  (3) 
  the 
  remarkable 
  fact 
  that 
  many 
  dry 
  valleys 
  die 
  out 
  

   just 
  before 
  the 
  crest 
  of 
  the 
  Chalk 
  Downs 
  is 
  reached. 
  

  

  CI. 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  INDUCTA^'CE 
  A^'D 
  RESISTANCE 
  IN 
  TELEPHONE 
  AND 
  OTHER 
  

   CIRCUITS. 
  

  

  1 
  N 
  the 
  paper 
  published 
  by 
  me, 
  under 
  this 
  title, 
  in 
  the 
  Phil. 
  

   -*- 
  Mag. 
  for 
  September 
  last, 
  there 
  is 
  an 
  error 
  to 
  which 
  I 
  desire 
  

   to 
  call 
  attention. 
  The 
  magnitude 
  h 
  in 
  the 
  investigation 
  should 
  

   be 
  replaced 
  by 
  IC-c, 
  so 
  that, 
  in 
  the 
  results, 
  p 
  stands 
  not 
  for 
  logeha^ 
  

   but 
  for 
  logg 
  K-ac. 
  

  

  Trinity 
  College, 
  Cambridge, 
  J. 
  W. 
  NlCH0LS02f. 
  

  

  November 
  17,' 
  1909. 
  

  

  THE 
  ULTIMATE 
  PRODUCT 
  OF 
  THE 
  URANIUM 
  DISINTEGRATION 
  

  

  SERIES. 
  

  

  To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

  

  Gextlemen, 
  — 
  Manchester, 
  Nov. 
  24, 
  1909. 
  

  

  I 
  would 
  like 
  to 
  correct 
  a 
  mistake 
  which 
  occurred 
  in 
  a 
  paper 
  of 
  

   mine, 
  published 
  in 
  this 
  month's 
  Philosophical 
  Magazine. 
  Taking 
  

   lead 
  as 
  the 
  final 
  product 
  of 
  the 
  uranium 
  series, 
  I 
  find 
  the 
  age 
  of 
  

  

  10-4 
  

   some 
  autunite 
  to 
  be 
  -^ 
  — 
  r— 
  y 
  years, 
  or 
  nearly 
  10,000 
  years, 
  not 
  

  

  a 
  million 
  years, 
  as 
  appears 
  in 
  the 
  paper. 
  As 
  in 
  the 
  calculation 
  

   no 
  account 
  was 
  made 
  of 
  the 
  fact 
  that 
  radium 
  takes 
  some 
  time 
  to 
  

   reach 
  equilibrium 
  with 
  the 
  uranium, 
  a 
  greater 
  age 
  must 
  be 
  given 
  

   to 
  the 
  mineral. 
  

  

  I 
  am, 
  

  

  Yours 
  faithfully, 
  

  

  J* 
  A. 
  Gbat. 
  

  

  