﻿OF 
  THE 
  LAKE-BASINS 
  OF 
  CUMBERLAND. 
  97 
  

  

  Honister 
  Crag 
  ; 
  and 
  the 
  alluvium 
  separating 
  Buttermere 
  from 
  Crum- 
  

   mock 
  is 
  mainly 
  the 
  product 
  of 
  Mill 
  heck 
  flowing 
  down 
  from 
  the 
  

   north, 
  and 
  Sourmilk 
  Gill 
  from 
  the 
  south, 
  upon 
  the 
  opposite 
  6ide. 
  

  

  In 
  the 
  absence 
  of 
  borings 
  the 
  thickness 
  of 
  these 
  alluvial 
  deposits 
  

   cannot 
  be 
  estimated 
  ; 
  but 
  it 
  might 
  be 
  that, 
  formerly, 
  the 
  greatest 
  

   depths 
  of 
  the 
  original 
  long 
  lakes 
  were 
  at 
  points 
  somewhere 
  between 
  

   Derwentwater 
  and 
  Bassenthwaite 
  in 
  the 
  one 
  case, 
  and 
  Buttermere 
  

   and 
  Crummock 
  in 
  the 
  other. 
  

  

  The 
  figures 
  5-10 
  and 
  13-16 
  inclusive, 
  give 
  the 
  forms 
  of 
  the 
  lakes 
  

   in 
  transverse 
  section, 
  while 
  figs. 
  1, 
  2, 
  & 
  3 
  represent 
  their 
  longitudinal 
  

   sections 
  along 
  the 
  lines 
  of 
  greatest 
  depth. 
  

  

  When 
  the 
  true 
  dimensions 
  are 
  thus 
  laid 
  down 
  to 
  scale, 
  the 
  point 
  

   that 
  first 
  strikes 
  one 
  is 
  the 
  insignificance 
  of 
  the 
  hollows 
  in 
  which 
  the 
  

   lakes 
  lie 
  as 
  compared 
  with 
  the 
  elevations 
  of 
  the 
  surrounding 
  ground. 
  

   But 
  since 
  these 
  lakes 
  are 
  not 
  sheets 
  of 
  water 
  merely 
  dammed 
  back 
  

   by 
  moraine 
  mounds, 
  but 
  lie 
  in 
  hollows 
  scooped 
  out 
  of 
  the 
  solid 
  

   rock, 
  it 
  becomes 
  an 
  interesting 
  and 
  legitimate 
  question 
  to 
  inquire 
  

   what 
  was 
  the 
  agent 
  which 
  produced 
  the 
  hollows. 
  

  

  Now 
  I 
  think 
  there 
  is 
  no 
  doubt 
  whatever 
  that 
  the 
  principal 
  valleys 
  

   of 
  the 
  district 
  in 
  which 
  these 
  larger 
  lakes 
  lie 
  are 
  of 
  very 
  great 
  age. 
  

   After 
  more 
  than 
  four 
  years' 
  intimate 
  acquaintance 
  with 
  mountain 
  

   and 
  valley, 
  the 
  fact 
  is 
  very 
  strongly 
  impressed 
  upon 
  my 
  mind 
  that 
  

   all 
  the 
  grand 
  mountain-sculpturing 
  to 
  be 
  met 
  with 
  here 
  is 
  due 
  to 
  

   the 
  apparently 
  weak 
  agents 
  now 
  in 
  operation, 
  the 
  powers 
  of 
  the 
  

   atmosphere, 
  wind, 
  rain, 
  frost, 
  and 
  running 
  water. 
  Nor 
  can 
  I 
  see 
  

   any 
  reason 
  to 
  doubt 
  that 
  the 
  elaboration 
  of 
  our 
  present 
  Lake-district 
  

   scenery 
  has 
  been 
  going 
  on 
  uninterruptedly, 
  though 
  very 
  likely 
  at 
  

   different 
  rates, 
  at 
  least 
  ever 
  since 
  the 
  close 
  of 
  the 
  Carboniferous 
  

   period, 
  and 
  perhaps 
  from 
  an 
  earlier 
  date 
  still. 
  It 
  will 
  thus 
  be 
  seen 
  

   that 
  I 
  do 
  not 
  consider 
  our 
  Cumberland 
  valleys 
  to 
  be 
  merely 
  gigantic 
  

   ice-grooves 
  formed 
  by 
  a 
  mammoth 
  ice-cap, 
  as 
  was 
  recently 
  suggested 
  

   to 
  this 
  Society 
  by 
  Mr. 
  Campbell 
  to 
  suit 
  the 
  case 
  of 
  Ireland 
  ; 
  but, 
  

   rather, 
  I 
  look 
  back 
  through 
  long 
  past 
  ages 
  during 
  which 
  these 
  

   valleys 
  were 
  being 
  sketched 
  out, 
  formed, 
  and 
  deepened, 
  under 
  very 
  

   varying 
  circumstances 
  and 
  climates, 
  now 
  under 
  almost 
  tropical 
  con- 
  

   ditions, 
  and 
  now 
  beneath 
  an 
  arctic 
  mantle 
  of 
  snow 
  and 
  ice 
  — 
  some- 
  

   times 
  when 
  the 
  district 
  was 
  far 
  higher 
  above 
  the 
  level 
  of 
  the 
  sea 
  

   than 
  it 
  is 
  now, 
  and 
  sometimes 
  perhaps 
  when 
  at 
  a 
  lower 
  elevation. 
  

   In 
  all 
  probability 
  glaciers 
  have 
  moved 
  down 
  these 
  old 
  valleys 
  at 
  

   more 
  than 
  one 
  period 
  previous 
  to 
  the 
  modern 
  Glacial 
  ; 
  and 
  though 
  

   they 
  may 
  have 
  effected 
  a 
  large 
  amount 
  of 
  denudation 
  by 
  attrition 
  

   and 
  transport, 
  yet 
  did 
  they 
  hinder 
  the 
  work 
  of 
  the 
  denuding 
  agents 
  

   for 
  long 
  ages 
  after, 
  just 
  in 
  proportion 
  as 
  they 
  left 
  the 
  country 
  with 
  

   a 
  smooth 
  and 
  polished 
  surface 
  against 
  which 
  the 
  atmospheric 
  powers 
  

   might 
  beat 
  for 
  long 
  in 
  vain. 
  Such 
  considerations 
  as 
  the 
  foregoing 
  

   lead 
  me 
  to 
  conclude 
  that 
  the 
  lake-hollows 
  are 
  of 
  very 
  recent 
  date, 
  

   geologically 
  speaking, 
  and 
  represent 
  the 
  removal 
  of 
  but 
  some 
  of 
  the 
  

   last 
  rock-shavings 
  by 
  nature's 
  tools. 
  And 
  what 
  the 
  special 
  tool 
  was 
  

   which 
  effected 
  this 
  we 
  have 
  now 
  to 
  consider. 
  

  

  Professor 
  Kamsay 
  has 
  ably 
  shown 
  the 
  difficulties 
  which 
  attend 
  an 
  

  

  