﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  rl45 
  

  

  Dr 
  LincolD 
  and 
  Prof. 
  Tarr, 
  writing 
  entirely 
  independently 
  but 
  

   nearly 
  contemporaneously, 
  arrive 
  at 
  the 
  same 
  conclusion 
  as 
  

   this 
  paper 
  — 
  their 
  strong 
  point 
  being 
  taken 
  from 
  the 
  series 
  of 
  pre- 
  

   glacial 
  streams 
  entering 
  the 
  valle}^ 
  at 
  nearly 
  the 
  present 
  water 
  level. 
  

  

  Prof. 
  Tarr 
  says 
  — 
  " 
  " 
  Cayuga 
  valley 
  is 
  a 
  preglacial 
  valley 
  enlarged 
  

   by 
  erosion. 
  Being 
  preglacial, 
  it 
  shares 
  with 
  the 
  other 
  similar 
  

   valleys 
  of 
  this 
  plateau 
  the 
  mature 
  form 
  or 
  habit. 
  A 
  mature 
  valley 
  

   has 
  a 
  more 
  accentuated 
  topography 
  near 
  its 
  head 
  than 
  near 
  its 
  

   mouth. 
  In 
  the 
  latter 
  portion 
  it 
  is 
  broad, 
  the 
  valley 
  sides 
  are 
  low, 
  

   and 
  the 
  tributaries 
  enter 
  through 
  valleys 
  which, 
  near 
  their 
  mouths, 
  

   are 
  shallow. 
  As 
  the 
  head 
  waters 
  are 
  approached 
  the 
  valley 
  walls 
  

   become 
  steeper, 
  nearer 
  together, 
  and 
  the 
  tributaries 
  enter 
  through 
  

   deeper 
  and 
  narrower 
  valleys 
  than 
  those 
  near 
  the 
  mouth." 
  

  

  We 
  have 
  seen 
  that 
  the 
  vallej^, 
  in 
  which 
  lies 
  Lake 
  Cayuga, 
  is 
  60 
  

   miles 
  long 
  ; 
  and 
  that, 
  if 
  the 
  terminal 
  moraine 
  at 
  Spencer 
  summit 
  

   was 
  removed, 
  it 
  would 
  continue 
  clear 
  down 
  into 
  Pennsylvania; 
  and 
  

   that 
  it 
  is 
  distinctly 
  preglacial. 
  

  

  We 
  have 
  noticed 
  the 
  similar 
  valley 
  of 
  Six 
  Mile 
  creek 
  entering 
  it 
  

   at 
  an 
  angle 
  of 
  45°. 
  Between 
  these 
  rises 
  " 
  South 
  hill," 
  and 
  a 
  

   photograph 
  taken 
  from 
  this 
  hill 
  shows 
  the 
  character 
  of 
  the 
  lake 
  

   valley. 
  (Figure 
  5.) 
  

  

  The 
  main 
  valley 
  is 
  on 
  the 
  right 
  side 
  of 
  the 
  picture, 
  and 
  Six 
  Mile 
  

   creek 
  flows 
  between 
  the 
  site 
  of 
  camera 
  and 
  the 
  city, 
  at 
  the 
  foot 
  of 
  

   the 
  hill. 
  

  

  It 
  has 
  been 
  observed 
  that 
  on 
  proceeding 
  down 
  the 
  lake 
  the 
  

   enclosing 
  hills 
  gradually 
  lessen 
  in 
  height, 
  become 
  less 
  steep, 
  and 
  

   finally 
  recede 
  entirely 
  from 
  the 
  lake 
  shores. 
  

  

  Another 
  feature 
  of 
  the 
  several 
  streams 
  previously 
  described 
  should 
  

   be 
  noticed. 
  The 
  mouth 
  of 
  the 
  gorge 
  of 
  Six 
  Mile 
  creek, 
  as 
  Prof. 
  

   Tarr'* 
  points 
  out, 
  is 
  distinctly 
  rock 
  enclosed, 
  and 
  the 
  stream 
  is^now 
  

   flowing 
  in 
  the 
  same 
  valley 
  as 
  the 
  preglacial 
  stream 
  did. 
  It 
  enters 
  

   the 
  delta 
  flat 
  at 
  an 
  elevation 
  of 
  about 
  30 
  feet 
  above 
  the 
  lake. 
  

  

  The 
  drift 
  buried 
  pre-glacial 
  valley 
  on 
  the 
  east 
  shore, 
  midway 
  

   between 
  Ithaca 
  and 
  Ludlowville, 
  is 
  cut 
  down 
  to 
  within 
  a 
  foot 
  or 
  two 
  

   of 
  the 
  lake 
  level. 
  

  

  Salmon 
  creek 
  is 
  also 
  rock 
  enclosed. 
  

  

  aBuU. 
  geol. 
  soc. 
  Am. 
  1894. 
  v. 
  5. 
  pi. 
  14 
  

  

  