﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  

  

  rl49 
  

  

  for 
  a 
  verj^ 
  great 
  erosive 
  power. 
  So 
  it 
  does, 
  but 
  it 
  can 
  be 
  demon- 
  

   strated 
  that 
  it 
  is 
  possible. 
  In 
  the 
  first 
  place 
  the 
  rock 
  here 
  is 
  soft 
  

   shale, 
  with 
  some 
  sandstone 
  and 
  a 
  few 
  strata 
  of 
  limestone. 
  

  

  It 
  is 
  extremely 
  brittle, 
  and 
  is 
  intersected 
  every 
  yard 
  or 
  so 
  by 
  

   well-defined 
  joint 
  planes 
  which 
  render 
  it 
  still 
  more 
  easily 
  broken. 
  

   It 
  would 
  be 
  very 
  susceptible 
  to 
  water 
  percolating 
  into 
  the 
  cracks 
  

   and 
  freezing 
  beneath 
  the 
  ice, 
  and 
  so 
  loosening 
  it 
  still 
  more. 
  

  

  Secondly, 
  a 
  depth 
  of 
  250 
  feet 
  is 
  not 
  excessive, 
  compared 
  to 
  the 
  

   width 
  of 
  the 
  valley. 
  

  

  Figs. 
  7 
  and 
  8 
  are 
  drawn 
  to 
  the 
  same 
  horizontal 
  and 
  vertical 
  scale 
  

   to 
  show 
  the 
  proportion. 
  Fig. 
  7 
  is 
  the 
  cross 
  section 
  through 
  one 
  of 
  

   the 
  narrowest 
  parts 
  of 
  the 
  lake, 
  and 
  the 
  proportion 
  is 
  therefore 
  a 
  

   maximum. 
  Fig. 
  8 
  is 
  through 
  the 
  deepest 
  part 
  of 
  the 
  lake. 
  

  

  Width 
  of 
  Lake 
  -7187^ 
  6" 
  

  

  Def)th 
  

  

  A 
  - 
  530' 
  

   B-380' 
  

   C 
  - 
  345' 
  

  

  F,g.7 
  

  

  Section 
  at 
  Willow 
  CKeek, 
  

   d 
  Kawn 
  ' 
  to 
  scale. 
  

  

  Width 
  of 
  Lake-ioooo' 
  

   Depth. 
  

  

  . 
  A 
  -70' 
  D-392' 
  

   B-380' 
  E 
  -20a' 
  

   C-435' 
  F- 
  23' 
  

  

  Fig. 
  8 
  

  

  Section 
  at 
  A-twateKs, 
  

   di^awn 
  to 
  scale. 
  

  

  