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  PKOF. 
  J. 
  PRESTWICH 
  ON 
  THE 
  OCCURRENCE 
  OP 
  

  

  acres 
  of 
  ground. 
  They 
  form 
  a 
  distinct 
  group, 
  characterized 
  by 
  their 
  

   general 
  brown 
  and 
  ochreous 
  colour, 
  extremely 
  rude 
  shape, 
  and 
  worn 
  

   appearance. 
  Out 
  of 
  twenty-four 
  specimens, 
  taken 
  at 
  random, 
  I 
  

   found 
  — 
  

  

  7 
  rude 
  broad 
  flake-scrapers, 
  deep 
  ochreous 
  or 
  brown 
  in 
  colour, 
  much 
  rolled 
  and 
  

  

  worn 
  at 
  edges 
  both 
  by 
  natural 
  and 
  by 
  plough 
  wear. 
  

   5 
  very 
  rude 
  pointed 
  implements 
  of 
  a 
  light 
  yellowisb-white 
  colour, 
  much 
  wea 
  

  

  thered 
  as 
  above 
  : 
  one 
  of 
  them 
  is 
  pitted 
  (PI. 
  XI. 
  figs. 
  2, 
  7). 
  

   1 
  small 
  fairly-formed 
  broad-pointed 
  implement 
  ; 
  colour 
  and 
  wear 
  as 
  above. 
  

  

  1 
  ditto 
  ovoid 
  ditto 
  ; 
  light 
  yellow 
  patinated, 
  and 
  with 
  an 
  old 
  fracture. 
  

  

  2 
  very 
  rude 
  thick 
  massive 
  scrapers 
  (?), 
  of 
  a 
  deep 
  brown 
  colour 
  and 
  much 
  worn. 
  

   2 
  flat 
  massive 
  brown 
  flints, 
  slightly 
  wrought, 
  and 
  edges 
  worn 
  as 
  though 
  by 
  

  

  hammering. 
  

  

  1 
  massive 
  green-coated 
  flint, 
  worked 
  on 
  one 
  side 
  to 
  a 
  point 
  and 
  stained 
  brown. 
  

  

  2 
  deep 
  ochreous 
  thick-backed 
  flakes, 
  worked 
  on 
  one 
  side 
  (PI. 
  XI. 
  fig. 
  1). 
  

  

  1 
  large 
  rude 
  flake 
  (natural 
  ?), 
  artificially 
  worked 
  on 
  edges 
  (^Pl. 
  XI. 
  fig. 
  4). 
  

  

  j^eolithic 
  implements, 
  retaining 
  in 
  greater 
  part 
  the 
  colour 
  of 
  the 
  

   original 
  flint 
  and 
  mostly 
  plough-stained, 
  occur 
  on 
  the 
  same 
  surface. 
  

  

  Mr. 
  Harrison 
  has 
  more 
  recently 
  found 
  a 
  few 
  rude 
  implements 
  

   (PI. 
  XI. 
  fig. 
  3) 
  or 
  flakes 
  of 
  a 
  similar 
  character 
  to 
  the 
  above, 
  and 
  

   associated 
  with 
  similar 
  subangular 
  brown 
  flints 
  and 
  one 
  quartzite 
  

   pebble, 
  a 
  short 
  distance 
  south 
  of 
  Bower 
  Farm, 
  1| 
  mile 
  south-east 
  of 
  

   Eynsford, 
  and 
  at 
  the 
  contour-level 
  of 
  510 
  to 
  530 
  ft. 
  ; 
  and 
  at 
  the 
  still 
  

   higher 
  level 
  of 
  600 
  ft. 
  Mr. 
  De 
  B. 
  Crawshay 
  has 
  found 
  a 
  massive 
  flake 
  

   (scraper?), 
  of 
  a 
  very 
  rude 
  make 
  and 
  brown 
  colour, 
  on 
  Punish 
  Farm, 
  

   near 
  the 
  edge 
  of 
  the 
  Chalk-escarpment, 
  north 
  of 
  West 
  Mailing. 
  

  

  Conclusion 
  : 
  Relative 
  Age 
  of 
  the 
  Drifts. 
  — 
  As 
  before 
  observed, 
  there 
  

   is, 
  in 
  the 
  absence 
  of 
  organic 
  remains, 
  great 
  difficulty 
  in 
  assigning 
  to 
  

   the 
  several 
  drifts 
  I 
  have 
  described 
  a 
  relative 
  age. 
  ^Nevertheless, 
  there 
  

   are 
  physical 
  features 
  connected 
  with 
  them 
  which 
  may 
  enable 
  us 
  to 
  

   form 
  some 
  apiDroximate 
  conclusion 
  ; 
  and 
  the 
  number 
  and 
  character 
  

   of 
  the 
  palaeolithic 
  implements 
  facilitates 
  the 
  attempt, 
  which 
  may 
  at 
  

   least 
  clear 
  up 
  some 
  of 
  the 
  more 
  essential 
  points. 
  

  

  It 
  is 
  evident 
  from 
  the 
  condition 
  of 
  the 
  implements 
  that, 
  although 
  

   now 
  occurring 
  on 
  the 
  surface 
  of 
  the 
  ground, 
  they, 
  unlike 
  the 
  Xeolithic 
  

   flints, 
  which 
  are 
  unstained 
  and 
  unaltered 
  except 
  by 
  atmospheric 
  

   agencies, 
  have 
  been 
  imbedded 
  in 
  some 
  matrix 
  which 
  has 
  produced 
  

   an 
  external 
  change 
  of 
  structure 
  and 
  colour 
  ; 
  while 
  the 
  matrix 
  itself, 
  

   wlrch 
  has 
  been 
  removed 
  by 
  denudation, 
  has 
  nevertheless 
  in 
  several 
  

   instances 
  left 
  traces 
  on 
  the 
  implements 
  sufficient 
  to 
  indicate 
  its 
  

   nature 
  (PL 
  XI. 
  fig. 
  6). 
  

  

  In 
  the 
  case 
  of 
  the 
  river-gravel 
  sites 
  of 
  Highfield 
  and 
  Duuks 
  Green, 
  

   the 
  question 
  presents 
  no 
  difficulty. 
  There 
  the 
  beds 
  have 
  been 
  partly 
  

   denuded, 
  and 
  the 
  flint 
  implements 
  which 
  were 
  imbedded 
  in 
  them 
  have 
  

   thus 
  become 
  exposed 
  on 
  the 
  surface. 
  This 
  explanation 
  may 
  also 
  

   apply 
  to 
  the 
  implements 
  found 
  associated 
  with 
  some 
  of 
  the 
  drifts 
  

   higher 
  than 
  those 
  which 
  can 
  be 
  ascribed 
  to 
  the 
  river-period. 
  But 
  

   there 
  are 
  others 
  to 
  which 
  it 
  will 
  not 
  apply, 
  — 
  such, 
  for 
  example, 
  

   as 
  those 
  which 
  are 
  found 
  at 
  elevations 
  of 
  100 
  to 
  200 
  ft., 
  or 
  more, 
  

   higher 
  than 
  the 
  watershed 
  of 
  the 
  three 
  streams, 
  nearly, 
  in 
  fact, 
  to 
  

  

  