﻿rllO 
  NEW 
  TOEK 
  STATE 
  MUSEUM 
  

  

  rapid 
  deposition 
  of 
  material, 
  and 
  the 
  existence 
  of 
  the 
  several 
  stages 
  

   at 
  any 
  one 
  level, 
  which 
  render 
  the 
  figures 
  uncertain 
  and 
  probably 
  of 
  

   indefinite 
  value 
  in 
  such 
  computations. 
  Another 
  factor 
  which 
  enters 
  

   into 
  the 
  result 
  is 
  that 
  of 
  terrace 
  measurement. 
  In 
  taking 
  the 
  eleva- 
  

   tions 
  three 
  sets 
  of 
  measurements 
  in 
  different 
  positions 
  were 
  taken 
  for 
  

   each 
  terrace 
  : 
  the 
  first, 
  was 
  from 
  10 
  to 
  15 
  paces 
  from 
  the 
  top 
  and 
  

   front 
  edge 
  of 
  the 
  terrace; 
  the 
  second, 
  was 
  on 
  the 
  top 
  and 
  middle 
  ;^ 
  

   and 
  the 
  third, 
  was 
  on 
  top 
  and 
  at 
  the 
  back 
  of 
  terrace. 
  This 
  

   method 
  was 
  adopted 
  in 
  order 
  to 
  secure 
  some 
  uniformity 
  in 
  the 
  

   results, 
  inasmuch 
  as 
  the 
  true 
  position 
  of 
  the 
  water 
  line 
  could 
  not 
  be 
  

   established 
  for 
  any 
  one 
  of 
  the 
  terraces. 
  The 
  results 
  given 
  in 
  the 
  

   tables, 
  both 
  numerical 
  and 
  graphic, 
  represent 
  the 
  measurement 
  

   taken 
  on 
  the 
  delta 
  top 
  at 
  a 
  distance 
  of 
  some 
  ten 
  to 
  fifteen 
  paces 
  

   back 
  from 
  the 
  frontal 
  edge. 
  It 
  at 
  once 
  becomes 
  apparent, 
  that 
  the 
  

   variation 
  will 
  be 
  greater 
  or 
  less 
  according 
  to 
  the 
  factors 
  concerned 
  

   in 
  the 
  terrace 
  construction, 
  the 
  most 
  important 
  one 
  of 
  which 
  is 
  

   stream 
  grade 
  and 
  bottom 
  slope. 
  If 
  a 
  delta 
  is 
  built 
  at 
  the 
  mouth 
  of 
  

   a 
  stream 
  entering 
  a 
  static 
  body 
  of 
  water 
  whose 
  shore 
  slope 
  is 
  pre- 
  

   cipitous, 
  the 
  delta 
  front 
  will 
  necessarily 
  be 
  lower 
  than 
  its 
  correlative 
  

   built 
  by 
  a 
  stream 
  entering 
  where 
  the 
  slope 
  is 
  slight 
  and 
  gradual. 
  

   This 
  element 
  is 
  the 
  principal 
  one 
  causing 
  the 
  variation 
  noted 
  in 
  the 
  

   different 
  terraces, 
  marking 
  the 
  same 
  level 
  in 
  the 
  Finger-lake 
  region. 
  

   As 
  previously 
  stated, 
  the 
  streams 
  entering 
  the 
  lakes 
  and 
  upon 
  which, 
  

   deltas 
  are 
  found, 
  show 
  a 
  considerable 
  variation 
  in 
  stream 
  gradient. 
  

  

  'No 
  figures 
  relating 
  to 
  strict 
  accuracy 
  can 
  be 
  given 
  as 
  a 
  reliable 
  

   computation 
  for 
  the 
  supposed 
  differential 
  movement 
  in 
  the 
  Finger- 
  

   lake 
  region, 
  but 
  certain 
  latitude 
  must 
  be 
  allowed, 
  owing 
  to 
  the 
  

   complexity 
  of 
  the 
  factors 
  concerned 
  in 
  the 
  shore-line 
  development, 
  

   l^evertheless, 
  some 
  data 
  have 
  been 
  collected 
  of 
  considerable 
  interest 
  

   and 
  probably 
  not 
  without 
  significance. 
  

  

  Three 
  of 
  the 
  largest 
  and 
  therefore 
  principal 
  successive 
  lake 
  stages 
  

   studied 
  for 
  the 
  two 
  largest 
  valleys 
  of 
  the 
  series, 
  namely 
  Cayuga 
  

   and 
  Seneca, 
  are 
  selected 
  for 
  the 
  test. 
  In 
  both 
  cases 
  the 
  most 
  

   southerly 
  stream 
  upon 
  which 
  is 
  marked, 
  with 
  the 
  least 
  doubt, 
  the 
  

   three 
  levels, 
  and 
  in 
  the 
  same 
  way 
  the 
  most 
  northerly 
  stream 
  for 
  the 
  

   same 
  lake 
  basin 
  have 
  been 
  selected. 
  In 
  case 
  of 
  Cayuga 
  valley, 
  the 
  

   three 
  levels 
  are 
  best 
  defined 
  on 
  West 
  branch 
  which 
  is 
  the 
  most 
  south- 
  

   erly 
  stream 
  for 
  this 
  basin 
  representing 
  these 
  levels 
  and 
  have 
  the 
  

  

  