﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  r6^ 
  

  

  system, 
  thereby 
  causing 
  a 
  southward 
  migration 
  of 
  the 
  divide. 
  The 
  

   attitude 
  of 
  the 
  strata 
  favors 
  such 
  migration 
  and 
  represents 
  a 
  case 
  of 
  

   monoclinal 
  shifting 
  of 
  the 
  divides. 
  

  

  Many 
  facts 
  could 
  be 
  brought 
  forward 
  favoring 
  the 
  northward 
  

   flow, 
  but 
  a 
  statement 
  of 
  the 
  leading 
  ones 
  "- 
  will 
  suffice, 
  which 
  are 
  : 
  

   first, 
  the 
  general 
  and 
  pronounced 
  slope 
  of 
  the 
  country 
  to 
  the 
  north, 
  

   which 
  is 
  evidently 
  a 
  preglacial 
  slope 
  ; 
  second, 
  the 
  vast 
  amount 
  of 
  

   glacial 
  filling 
  required 
  in 
  the 
  valleys 
  south 
  of 
  the 
  lakes, 
  if 
  south 
  

   flowing 
  ; 
  third, 
  that 
  the 
  valleys 
  open 
  out 
  quite 
  uniformly 
  to 
  greater 
  

   widths 
  northward, 
  starting 
  from 
  the 
  divides 
  in 
  the 
  southern 
  portions 
  

   of 
  the 
  respective 
  valleys, 
  where 
  the 
  width 
  will 
  probably 
  average 
  

   from 
  three-quarters 
  of 
  a 
  mile 
  to 
  one 
  mile, 
  with 
  very 
  steep, 
  rugged 
  

   and 
  precipitous 
  sides, 
  a 
  mature 
  condition 
  though 
  strongly 
  accent- 
  

   uated. 
  Proceeding 
  northward 
  from 
  the 
  divide, 
  the 
  valleys 
  gradually 
  

   but 
  perceptibly, 
  widen 
  out 
  more 
  and 
  more, 
  and 
  their 
  sides 
  become 
  

   lower 
  and 
  more 
  rounded 
  until 
  they 
  merge 
  into 
  and 
  are 
  replaced 
  

   entirely 
  by 
  the 
  *' 
  Great 
  Lakes 
  plain 
  " 
  to 
  the 
  north. 
  

  

  Professor 
  Tarr 
  ^ 
  has 
  brought 
  forward 
  one 
  of 
  the 
  strongest 
  points- 
  

   yet 
  made 
  favoring 
  the 
  northward 
  flow 
  in 
  the 
  preglacial 
  Cayuga, 
  

   valley. 
  His 
  evidence 
  is 
  based 
  upon 
  the 
  height 
  of 
  the 
  rock 
  floors 
  

   in 
  the 
  creek 
  valleys 
  of 
  the 
  preglacial 
  tributary 
  streams 
  entering 
  

   the 
  Cayuga 
  lake 
  valley 
  with 
  reference 
  to 
  the 
  present 
  lake-leveL 
  

   In 
  the 
  case 
  of 
  Six 
  Mile 
  creek, 
  the 
  entrance 
  to 
  preglacial 
  Cayuga 
  is 
  

   found 
  to 
  be 
  50 
  feet 
  above 
  the 
  present 
  lake 
  level. 
  Salmon 
  creek, 
  

   which 
  is 
  some 
  seven 
  miles 
  north 
  of 
  Ithaca, 
  entered 
  about 
  30 
  feet 
  

   above 
  lake 
  level, 
  while 
  at 
  Union 
  springs, 
  some 
  20 
  miles 
  north 
  of 
  

   Salmon 
  creek, 
  its 
  entrance 
  in 
  preglacial 
  times 
  was 
  below 
  the 
  present 
  

   lake 
  level. 
  The 
  evidence 
  in 
  this 
  case 
  is 
  apparently 
  so 
  confirmatory, 
  

   that 
  only 
  one 
  conclusion 
  can 
  be 
  drawn, 
  namely, 
  that 
  Lake 
  Cayuga 
  

   valley 
  was 
  occupied 
  by 
  a 
  stream 
  with 
  a 
  well 
  established 
  northward 
  

   gradient 
  and 
  therefore 
  tributary 
  to 
  the 
  Laurentian 
  river 
  system. 
  

  

  Again, 
  in 
  the 
  case 
  of 
  Lake 
  Cayuga, 
  the 
  engineering 
  department 
  of 
  

   Cornell 
  university 
  has 
  issued 
  a 
  map 
  which 
  shows 
  223 
  lateral 
  streams 
  

  

  a 
  Brigham, 
  A. 
  P., 
  Bull, 
  geogr, 
  soc. 
  Am., 
  1893, 
  25, 
  10-12. 
  

   Chamberlin, 
  T. 
  C, 
  Third 
  ann'l. 
  report, 
  U. 
  S. 
  G. 
  S., 
  1881-'82, 
  335. 
  

   Lincoln, 
  D. 
  F., 
  Am. 
  Journ. 
  Sci.. 
  1P94, 
  47, 
  105-113 
  ; 
  Read 
  before 
  the 
  Madison 
  meeting 
  Am. 
  

  

  asso. 
  adv. 
  sci., 
  1893. 
  

   Tarr, 
  R. 
  S., 
  Bull. 
  geol. 
  soc. 
  Am., 
  1894, 
  5. 
  352-354. 
  

   h 
  Tarr, 
  R. 
  S.. 
  Bull. 
  geol. 
  soc. 
  A.m. 
  1894, 
  5, 
  339-356. 
  

  

  