﻿376 
  Geological 
  Society 
  : 
  — 
  

  

  electroscope 
  diverge 
  from 
  each 
  other 
  and 
  show 
  a 
  positive 
  

   charge. 
  

  

  It 
  is 
  apparent 
  that 
  this 
  experiment 
  must 
  be 
  explained 
  as. 
  

   follows 
  : 
  — 
  The 
  conducting 
  system 
  composed 
  of 
  the 
  aluminium 
  

   plate, 
  the 
  wire 
  and 
  the 
  electroscope, 
  by 
  making 
  contact 
  with 
  

   the 
  earth, 
  is 
  distributed 
  in 
  such 
  a 
  manner 
  that 
  the 
  uttermost 
  

   parts 
  of 
  it 
  are 
  charged 
  : 
  the 
  plate 
  with 
  negative 
  electricity, 
  

   and 
  the 
  electroscope 
  with 
  positive 
  electricity. 
  The 
  fact 
  that 
  

   the 
  leaves 
  of 
  the 
  electroscope 
  show 
  a 
  positive 
  charge 
  therefore 
  

   proves 
  that 
  the 
  surface 
  of 
  the 
  earth 
  has 
  a 
  negative 
  charge. 
  

   The 
  negative 
  charge 
  of 
  the 
  plate 
  can 
  be 
  directly 
  shown 
  if, 
  

   after 
  being 
  isolated 
  from 
  the 
  earth, 
  it 
  is 
  conveyed 
  to 
  a 
  room 
  

   protected 
  from 
  the 
  earth, 
  and 
  examined 
  there 
  as 
  to 
  its 
  electrical 
  

   condition. 
  

  

  I 
  am, 
  Gentlemen, 
  

   Technische 
  Hochschule, 
  Yours 
  faithfully, 
  

  

  Braunschweig. 
  Dr. 
  KARL 
  BerGWITZ.. 
  

  

  XXVIII. 
  Proceedings 
  of 
  Learned 
  Societies. 
  

  

  GEOLOGICAL 
  SOCIETY. 
  

   [Continued 
  from 
  vol. 
  xxv. 
  p. 
  756.] 
  

  

  May 
  7th, 
  1913. 
  — 
  Dr. 
  Aubrey 
  Strahan, 
  F.B.S., 
  President; 
  

   and 
  afterwards 
  W. 
  Whitaker, 
  B.A., 
  F.R.S., 
  F.G.S., 
  in 
  the 
  Chair. 
  

   r 
  PHE 
  following 
  communications 
  were 
  read 
  : 
  — 
  

   J- 
  1. 
  ' 
  The 
  Bathonian 
  Bocks 
  of 
  the 
  Oxford 
  District.' 
  By 
  M. 
  Odling,, 
  

   M.A., 
  B.Sc, 
  F.G.S. 
  

  

  In 
  this 
  paper 
  the 
  author 
  describes 
  the 
  c 
  lithology, 
  palaeontology, 
  

   and 
  stratigraphy 
  of 
  the 
  Bathonian 
  rocks 
  north 
  of 
  Oxford, 
  from 
  the- 
  

   evidence 
  afforded' 
  by 
  numerous 
  quarries 
  and 
  well-borings 
  and 
  by 
  

   the 
  Ardley 
  Cutting 
  on 
  the 
  Great 
  Western 
  Bailway 
  (new 
  Birmingham 
  

   main 
  line). 
  

  

  The 
  general 
  sequence 
  is 
  as 
  follows 
  : 
  — 
  

  

  Thickness 
  in 
  feet, 
  

   Cornbrash. 
  Bubbly 
  non-oolitic 
  limestone, 
  with 
  occa- 
  

   sional 
  marl-bands 
  8 
  to 
  17 
  

  

  Slight 
  unconformity. 
  

  

  Forest 
  Marble. 
  Coarse 
  shelly 
  and 
  oolitic 
  limestones^ 
  

   largely 
  false-bedded. 
  Wben 
  traced 
  j 
  

   eastwards 
  the 
  limestones 
  are 
  largely 
  re- 
  [ 
  o-i 
  

  

  placed 
  by 
  marls 
  ; 
  and 
  finally 
  the 
  series 
  J 
  

   is 
  represented 
  by 
  green 
  and 
  blue 
  clays 
  J 
  

   with 
  minor 
  bands 
  of 
  limestone. 
  J 
  

  

  Well-marked 
  unconformity. 
  

   Great 
  Oolite. 
  

  

  Block 
  1. 
  

  

  Compact, 
  fine-grained, 
  pure 
  limestones, 
  ~\ 
  

  

  with 
  a 
  local 
  blue 
  or 
  green 
  clay 
  about 
  I 
  

  

  the 
  centre. 
  The 
  variation 
  in 
  thickness 
  f 
  

  

  is 
  largely 
  due 
  to 
  erosion. 
  J 
  

  

  Well-marked 
  eroded 
  surface. 
  

  

  to 
  ia 
  

  

  