﻿42 
  ON 
  A 
  MIDDLE 
  PLEISTOCENE 
  GRAVEL 
  IN 
  LANCASHIRE. 
  

  

  Prof. 
  Ramsay 
  was 
  glad 
  that 
  the 
  old 
  view 
  as 
  to 
  the 
  successive 
  

   elevations 
  aud 
  submergences 
  during 
  the 
  Glacial 
  period 
  was 
  not 
  

   likely 
  to 
  be 
  disturbed. 
  As 
  to 
  the 
  physical 
  causes 
  which 
  conduced 
  

   to 
  the 
  extreme 
  cold, 
  he 
  did 
  not 
  undervalue 
  the 
  changes 
  in 
  physical 
  

   geography 
  ; 
  but 
  if 
  the 
  astronomical 
  causes, 
  the 
  existence 
  of 
  which 
  

   seemed 
  now 
  to 
  be 
  fairly 
  established, 
  would 
  have 
  produced 
  the 
  eifects, 
  

   he 
  did 
  not 
  see 
  why 
  they 
  should 
  be 
  ignored 
  even 
  if 
  the 
  geographical 
  

   causes 
  might 
  suffice. 
  These 
  latter 
  seemed 
  to 
  be 
  at 
  best 
  theoretical, 
  

   whereas 
  the 
  former 
  seemed 
  mathematically 
  necessary. 
  He 
  was 
  not 
  

   inclined 
  to 
  detach 
  the 
  shells 
  from 
  the 
  clay, 
  and 
  thought 
  that 
  during 
  

   the 
  time 
  of 
  their 
  deposit 
  there 
  were 
  still 
  glaciers 
  on 
  the 
  higher 
  

   parts 
  of 
  the 
  land. 
  He 
  did 
  not 
  agree 
  with 
  Prof. 
  Hughes 
  in 
  regard- 
  

   ing 
  the 
  beds 
  with 
  striated 
  pebbles 
  in 
  the 
  Vale 
  of 
  Clwyd 
  as 
  post- 
  

   glacial, 
  and 
  could 
  not 
  believe 
  that 
  in 
  the 
  case 
  of 
  the 
  reconstruction 
  

   of 
  the 
  beds 
  the 
  striae 
  could 
  be 
  preserved 
  and 
  the 
  pebbles 
  not 
  be- 
  

   come 
  smooth. 
  

  

  Mr. 
  Reade, 
  in 
  reply, 
  stated 
  that 
  his 
  observations 
  were 
  intended 
  

   to 
  apply 
  merely 
  to 
  the 
  conditions 
  under 
  which 
  the 
  beds 
  containing 
  

   the 
  shells 
  had 
  been 
  deposited, 
  and 
  not 
  to 
  the 
  period 
  of 
  extreme 
  cold, 
  

   for 
  which 
  he 
  was 
  quite 
  willing 
  to 
  admit 
  the 
  potency 
  of 
  astronomical 
  

   causes. 
  He 
  agreed 
  with 
  Prof. 
  Ramsay 
  in 
  regarding 
  the 
  clay 
  as 
  a 
  

   real 
  Boulder-clay, 
  the 
  pebbles 
  in 
  it 
  being 
  for 
  the 
  most 
  part 
  scratched. 
  

  

  