﻿THEORY 
  OF 
  LAKE-BASINS. 
  481 
  

  

  while 
  the 
  carriage-road, 
  hugging 
  the 
  northern 
  side 
  of 
  the 
  above 
  

   trough, 
  crosses 
  a 
  slight 
  depression 
  (7658'), 
  and 
  zigzags 
  rapidly 
  down 
  

   into 
  the 
  cirque-like 
  head 
  of 
  the 
  Val 
  Agone. 
  It 
  needs 
  but 
  a 
  glance 
  

   into 
  these 
  valleys 
  to 
  show 
  that 
  their 
  physical 
  features 
  are 
  anterior 
  

   to 
  the 
  epoch 
  of 
  the 
  glaciers 
  which 
  have 
  undoubtedly 
  descended 
  

   them. 
  The 
  Cambrena 
  glacier, 
  still 
  a 
  fine 
  ice-stream, 
  united 
  to 
  

   smaller 
  glaciers 
  which 
  yet 
  cling 
  to 
  the 
  steep 
  sides 
  of 
  the 
  mountain, 
  

   once 
  descended 
  on 
  to 
  the 
  trough 
  along 
  which 
  the 
  Bernina 
  road 
  now 
  

   runs, 
  and 
  sent 
  forth 
  glaciers 
  on 
  the 
  one 
  side 
  along 
  the 
  Yals 
  Agone 
  

   and 
  Pila 
  (covering 
  doubtless 
  all 
  the 
  intervening 
  buttress), 
  on 
  the 
  

   other 
  towards 
  Pontresina. 
  

  

  Exactly 
  in 
  the 
  path 
  of 
  this, 
  and 
  where 
  the 
  ice-streams 
  from 
  the 
  

   Cambrena, 
  at 
  the 
  foot 
  of 
  its 
  steep 
  slopes, 
  would 
  be 
  arrested 
  by 
  the 
  

   opposite 
  ridges 
  (which 
  perhaps 
  had 
  also 
  their 
  glaciers), 
  lie 
  these 
  lakes. 
  

  

  Though 
  discharging 
  their 
  waters 
  to 
  different 
  seas, 
  only 
  a 
  low 
  

   barrier 
  of 
  ice-worn 
  rock, 
  nowhere 
  more 
  than 
  a 
  few 
  feet 
  above 
  the 
  

   water, 
  separates 
  them*. 
  This 
  is 
  exactly 
  the 
  place 
  where 
  the 
  erosive 
  

   action 
  of 
  a 
  glacier 
  would 
  be 
  most 
  intense 
  ; 
  and 
  I 
  should 
  be 
  inclined 
  

   to 
  attribute 
  these 
  shallow 
  lakelets 
  mainly 
  to 
  this 
  cause. 
  At 
  the 
  

   same 
  time 
  I 
  observed 
  that 
  an 
  important 
  feature 
  in 
  the 
  Lago 
  Bianco, 
  

   namely 
  a 
  projecting 
  elbow 
  on 
  the 
  northern 
  side, 
  is 
  formed 
  by 
  a 
  V- 
  

   shaped 
  glen, 
  down 
  which 
  a 
  considerable 
  stream 
  now 
  comes. 
  The 
  

   whole 
  of 
  this 
  region, 
  however, 
  is 
  one 
  where 
  a 
  minute 
  examination 
  is 
  

   likely 
  to 
  be 
  useful 
  ; 
  this 
  I 
  hope 
  to 
  give 
  on 
  a 
  future 
  occasion, 
  when 
  

   the 
  ground 
  is 
  not 
  (as 
  it 
  was 
  on 
  the 
  occasion 
  of 
  my 
  last 
  visit) 
  masked 
  

   with 
  snow 
  and 
  the 
  lake 
  with 
  ice 
  ; 
  and 
  T 
  should 
  not 
  now 
  have 
  men- 
  

   tioned 
  it, 
  had 
  I 
  not 
  considered 
  it 
  one 
  which, 
  so 
  far 
  as 
  it 
  goes, 
  is 
  

   favourable 
  to 
  the 
  glacier-erosion 
  theory. 
  

  

  Proceeding 
  now 
  to 
  the 
  second 
  group 
  of 
  lakes, 
  those 
  which 
  form 
  

   the 
  principal 
  sources 
  of 
  the 
  Inn, 
  we 
  are 
  again 
  struck 
  by 
  the 
  singular 
  

   configuration 
  of 
  the 
  ground. 
  As 
  we 
  ascend 
  the 
  valley 
  a 
  level 
  plain 
  

   extends 
  for 
  several 
  miles 
  by 
  the 
  side 
  of 
  the 
  Inn, 
  being 
  very 
  probably 
  

   a 
  silted-up 
  lake, 
  until, 
  a 
  short 
  distance 
  above 
  the 
  well-known 
  village 
  

   of 
  Samaden, 
  this 
  plain 
  slightly 
  bifurcates, 
  one 
  arm 
  extending 
  a 
  very 
  

   short 
  distance 
  along 
  the 
  Flatzbach 
  (the 
  torrent 
  descending 
  from 
  Pont- 
  

   resina), 
  the 
  other 
  also 
  soon 
  stopping 
  at 
  the 
  foot 
  of 
  a 
  rocky 
  step 
  in 
  

   the 
  floor 
  of 
  the 
  main 
  trough, 
  which 
  runs 
  very 
  uniformly 
  in 
  a 
  S.W. 
  to 
  

   N.E. 
  direction. 
  The 
  height 
  of 
  this 
  abrupt 
  step 
  is 
  about 
  400'; 
  and 
  

   above 
  it 
  the 
  valley 
  extends 
  with 
  remarkable 
  uniformity 
  of 
  level 
  f 
  till, 
  

   at 
  the 
  Maloya 
  Kulm, 
  the 
  edge 
  of 
  the 
  abrupt 
  descent 
  into 
  Italy 
  is 
  

   reached. 
  This 
  trough, 
  about 
  ten 
  miles 
  long, 
  is 
  now 
  occupied 
  by 
  

   three 
  lakes, 
  which, 
  however, 
  were 
  once 
  only 
  two 
  in 
  number, 
  the 
  

   present 
  Silser 
  See 
  and 
  Silvaplana 
  See 
  having 
  formed 
  one 
  long 
  lake, 
  

   which 
  extended 
  from 
  close 
  to 
  the 
  edge 
  of 
  the 
  Maloya 
  Pass 
  to 
  

  

  * 
  Ball 
  states 
  (Alpine 
  Guide, 
  § 
  36, 
  k) 
  that 
  in 
  one 
  place 
  it 
  does 
  not 
  exceed 
  

   3 
  feet 
  above 
  the 
  ordinary 
  level 
  of 
  the 
  water 
  ; 
  and 
  that 
  the 
  Lago 
  Bianco 
  some- 
  

   times 
  overflows 
  into 
  the 
  Lago 
  Nero. 
  The 
  greater 
  part 
  of 
  it 
  appeared 
  to 
  me 
  not 
  

   to 
  exceed 
  15 
  feet. 
  

  

  t 
  As 
  is 
  shown 
  by 
  the 
  following 
  levels 
  : 
  — 
  Maloya 
  Kulm, 
  5942' 
  ; 
  Silser 
  See, 
  

   5892'; 
  Sils, 
  5896'; 
  Silvaplana 
  See, 
  5886'; 
  St.-Moritzer 
  See, 
  5797'. 
  The 
  

   height 
  of 
  Samaden 
  above 
  the 
  sea 
  is 
  5600'. 
  

  

  