﻿1864.] 
  MAW 
  BOTTLDEB-CLAY. 
  449 
  

  

  the 
  upper 
  10 
  or 
  12 
  feet) 
  was 
  through 
  a 
  bed 
  of 
  perfectly 
  homoge- 
  

   neous 
  brown 
  clay, 
  exceedingly 
  tough, 
  free 
  from 
  tbe 
  slightest 
  grit, 
  

   and 
  as 
  smooth 
  and 
  soft 
  as 
  butter. 
  The 
  upper 
  12 
  feet 
  was 
  some- 
  

   what 
  intermixed 
  with 
  stones, 
  the 
  number 
  of 
  which 
  decreased 
  from 
  

   the 
  surface 
  ; 
  and 
  in 
  the 
  remaining 
  66 
  feet, 
  I 
  was 
  assured 
  by 
  Mr. 
  

   Bowden 
  that 
  not 
  the 
  least 
  particle 
  of 
  stone, 
  pebble, 
  or 
  sand 
  was 
  ob- 
  

   served, 
  the 
  whole 
  mass 
  consisting 
  of 
  an 
  uninterrupted 
  bed 
  of 
  per- 
  

   fectly 
  homogeneous 
  clay, 
  excepting 
  that 
  at 
  a 
  depth 
  of 
  about 
  40 
  feet 
  

   some 
  blackened 
  pieces 
  of 
  driftwood 
  were 
  found 
  imbedded 
  in 
  it. 
  

  

  A 
  few 
  months 
  ago 
  Sir 
  Boucher 
  Wrey, 
  of 
  Tawstock 
  Park, 
  caused 
  two 
  

   pits 
  to 
  be 
  sunk 
  further 
  to 
  the 
  east, 
  above 
  the 
  village 
  of 
  Lake, 
  and 
  as- 
  

   certained 
  the 
  existence 
  of 
  similar 
  clay 
  to 
  a 
  thickness 
  of 
  25 
  or 
  30 
  feet, 
  

   resting 
  on 
  shingly 
  gravel. 
  The 
  form 
  of 
  the 
  ground 
  and 
  depth 
  of 
  the 
  

   gravel-bed 
  at 
  this 
  spot 
  would 
  imply 
  a 
  correspondence 
  of 
  its 
  level 
  with 
  

   that 
  at 
  Fremington 
  and 
  the 
  other 
  points 
  where 
  it 
  has 
  been 
  observed. 
  

  

  The 
  clay 
  that 
  has 
  been 
  dug 
  for 
  many 
  years 
  at 
  Fremington 
  for 
  the 
  

   manufacture 
  of 
  pottery 
  is 
  similar 
  in 
  character 
  to 
  that 
  at 
  Roundswell 
  

   and 
  Lake. 
  In 
  its 
  extreme 
  smoothness 
  and 
  fineness 
  of 
  texture 
  it 
  

   notably 
  differs 
  from 
  the 
  Boulder- 
  clay 
  of 
  Shropshire, 
  which 
  is 
  mixed 
  

   up 
  confusedly 
  with 
  beds 
  of 
  sand 
  and 
  silt. 
  

  

  In 
  the 
  hamlet 
  of 
  Combrew 
  (marked 
  " 
  Comb 
  worthy 
  " 
  on 
  the 
  Ord- 
  

   nance 
  Map) 
  is 
  a 
  large 
  boulder 
  of 
  basaltic 
  Trap, 
  3^ 
  X 
  2|feet, 
  weighing 
  

   many 
  hundredweights, 
  which 
  Mr. 
  E. 
  B. 
  Fishley, 
  of 
  the 
  Fremington 
  

   Pottery, 
  informed 
  me 
  was 
  found 
  in 
  the 
  middle 
  of 
  the 
  adjacent 
  clay- 
  

   bed, 
  ten 
  feet 
  from 
  the 
  surface, 
  and 
  unaccompanied 
  by 
  any 
  smaller 
  

   masses. 
  The 
  whole 
  surface 
  of 
  the 
  clay 
  is 
  covered 
  over 
  with 
  clayey 
  

   gravel, 
  from 
  5 
  to 
  7 
  feet 
  thick, 
  containing 
  stones 
  and 
  occasionally 
  

   large 
  masses 
  of 
  amygdaloid 
  Trap-ash 
  (one 
  of 
  which 
  is 
  to 
  be 
  seen 
  in 
  

   the 
  yard 
  of 
  Mr. 
  Fishley's 
  pottery) 
  . 
  This 
  superficial 
  gravel 
  is, 
  I 
  believe, 
  

   independent 
  of 
  the 
  clay, 
  and 
  coeval 
  with 
  its 
  erosion. 
  The 
  boulders 
  

   of 
  Trap-ash, 
  and 
  other 
  large 
  stones, 
  in 
  the 
  superposed 
  gravel 
  may, 
  

   however, 
  have 
  been 
  derived 
  from 
  the 
  eroded 
  clay, 
  and 
  left 
  after 
  its 
  

   denudation 
  on 
  the 
  surface 
  of 
  what 
  remained. 
  The 
  stones 
  found 
  in 
  

   the 
  upper 
  12 
  feet 
  of 
  Mr. 
  Bowden's 
  sinking 
  probably 
  belonged 
  to 
  it, 
  

   and 
  got 
  commingled 
  with 
  the 
  top 
  of 
  the 
  clay 
  at 
  the 
  time 
  of 
  its 
  denu- 
  

   dation, 
  so 
  that 
  the 
  large 
  mass 
  of 
  Trap 
  at 
  Combrew 
  is 
  the 
  only 
  au- 
  

   thenticated 
  example 
  of 
  a 
  boulder 
  occurring 
  in 
  the 
  clay. 
  

  

  As 
  the 
  valley 
  forming 
  the 
  site 
  of 
  the 
  deposit 
  is 
  in 
  a 
  rather 
  more 
  

   direct 
  line 
  between 
  the 
  river 
  Taw 
  above 
  and 
  below 
  Barnstaple 
  than 
  

   the 
  present 
  river-bed, 
  I 
  have 
  thought 
  that 
  the 
  deposit 
  may 
  represent 
  

   the 
  ancient 
  course 
  of 
  the 
  river; 
  but 
  the 
  great 
  height 
  to 
  which 
  it 
  ex- 
  

   tends 
  above 
  the 
  river- 
  and 
  sea-level 
  (110 
  to 
  120 
  feet), 
  and 
  the 
  superior 
  

   height 
  of 
  the 
  fundamental 
  rock 
  (from 
  40 
  to 
  50 
  feet) 
  to 
  that 
  of 
  the 
  

   present 
  river-bed, 
  would 
  represent 
  a 
  great 
  extension 
  of 
  the 
  sea 
  for 
  

   miles 
  inland, 
  unless 
  the 
  present 
  contour 
  and 
  system 
  of 
  valleys 
  had 
  

   been 
  entirely 
  remodelled 
  since 
  the 
  formation 
  of 
  the 
  deposit. 
  The 
  

   alluvial 
  mud 
  of 
  the 
  present 
  Taw 
  valley 
  is, 
  moreover, 
  of 
  a 
  very 
  dif- 
  

   ferent 
  character 
  from 
  the 
  Fremington 
  clay. 
  It 
  contains 
  a 
  large 
  pro- 
  

   portion 
  of 
  sand, 
  also 
  Hydrobia 
  ulvce 
  and 
  H. 
  ventrosa, 
  brackish- 
  water 
  

   Shells 
  which 
  do 
  not 
  occur 
  in 
  the 
  clay. 
  

  

  