﻿Fig. 
  8. 
  

  

  ICOHOES 
  MASTODON. 
  137 
  

  

  that 
  15 
  inches 
  per 
  century 
  is 
  not 
  too 
  small 
  an 
  estimate. 
  The 
  

   portion 
  of 
  cliff 
  on 
  which 
  these 
  grow 
  is 
  now 
  losing 
  ground 
  more 
  

   rapidly 
  than 
  others. 
  Fifty 
  feet 
  above 
  the 
  

   promontory 
  alluded 
  to, 
  grasses 
  and 
  other 
  trees 
  

   than 
  the 
  cedar 
  find 
  foot-hold 
  and 
  show 
  very 
  

   slight 
  baring 
  of 
  roots. 
  The 
  change 
  at 
  the 
  

   promontory 
  is 
  note-worthy, 
  as 
  it 
  contrasts 
  two 
  

   methods 
  of 
  water 
  action. 
  The 
  upper 
  aspect 
  a 
  

   (fig. 
  8) 
  receives 
  the 
  brunt 
  of 
  the 
  direct 
  wear 
  of 
  

   the 
  water, 
  assisted 
  by 
  floating 
  ice, 
  etc. 
  The 
  

   cove 
  h 
  is 
  comparatively 
  sheltered 
  from 
  the 
  cur- 
  

   rent, 
  but 
  catches 
  the 
  spray 
  from 
  the 
  fall, 
  and 
  

   crumbles, 
  under 
  alternating 
  extremes 
  of 
  mois- 
  

   ture 
  and 
  of 
  temperature, 
  at 
  the 
  rapid 
  rate 
  given 
  

   above.* 
  Below 
  the 
  fall 
  the 
  east 
  cliff 
  is 
  nearly 
  

   as 
  steep 
  as 
  above, 
  and 
  supports 
  little 
  vegeta- 
  

   tion. 
  Patches 
  of 
  cedars 
  cling 
  in 
  favored 
  places, 
  

   and 
  some 
  hemlocks 
  are 
  seen, 
  but 
  about 
  half 
  the 
  

   escarpment 
  is 
  bare. 
  The 
  west 
  cliff, 
  though 
  

   steep, 
  is 
  covered 
  by 
  grasses 
  and 
  mosses, 
  and 
  is 
  losing 
  ground 
  very 
  

   slowly. 
  A 
  few 
  rods 
  above 
  the 
  new 
  mill 
  an 
  elm 
  tree, 
  with 
  trunk 
  

   ten 
  inches 
  in 
  diameter, 
  grows 
  on 
  the 
  face 
  of 
  the 
  cliff, 
  without 
  

   exposure 
  of 
  roots, 
  and 
  in 
  like 
  manner 
  a 
  chestnut 
  (?) 
  of 
  the 
  same 
  

   size 
  and 
  a 
  cedar 
  eight 
  inches 
  through. 
  The 
  latter 
  is 
  a 
  more 
  thrifty 
  

   tree 
  than 
  those 
  mentioned 
  above, 
  and 
  probably 
  grew 
  more 
  rapidly. 
  

   A 
  few 
  rods 
  farther 
  up, 
  at 
  the 
  foot 
  of 
  School 
  street, 
  are 
  a 
  number 
  

   of 
  thrifty 
  cedars 
  and 
  hemlocks 
  with 
  undisturbed 
  roots. 
  Within 
  a 
  

   few 
  rods 
  they 
  are 
  contrasted 
  by 
  two 
  hemlocks, 
  about 
  one 
  foot 
  in 
  

   diameter, 
  growing 
  on 
  the 
  top 
  of 
  the 
  cliff, 
  one 
  of 
  which 
  has 
  been 
  

   undermined 
  four 
  or 
  five 
  feet, 
  and 
  the 
  other 
  eight. 
  The 
  west 
  shore 
  

   above 
  the 
  fall 
  is 
  low, 
  of 
  loose 
  material, 
  marshy 
  from 
  the 
  leakage 
  of 
  

   the 
  race, 
  and 
  now 
  gaining 
  ground 
  rather 
  than 
  losing. 
  In 
  fine, 
  it 
  

   appears 
  that 
  the 
  maximum 
  present 
  waste 
  of 
  the 
  shore 
  is 
  15 
  inches 
  

   per 
  century, 
  that 
  the 
  greater 
  part 
  of 
  that 
  under 
  consideration 
  is 
  

   ©rumbling 
  less 
  rapidly, 
  and 
  that 
  a 
  considerable 
  portion 
  is 
  almost 
  

   stationary. 
  I 
  deem 
  it 
  proper 
  to 
  allow 
  12 
  inches 
  per 
  century 
  as 
  a 
  

   rate 
  of 
  recession, 
  through 
  a 
  long 
  period, 
  of 
  any 
  portion 
  of 
  cliff. 
  

   This 
  gives, 
  as 
  the 
  time 
  necessary 
  to 
  have 
  removed 
  the 
  banks 
  below 
  

   the 
  fall 
  from 
  the 
  deep 
  channel 
  to 
  their 
  present 
  position, 
  35,000 
  

  

  * 
  See 
  note 
  A. 
  

  

  