﻿E. 
  H. 
  Williams 
  — 
  Southern 
  Ice 
  Limit 
  in 
  Pennsylvania. 
  183 
  

  

  It 
  is 
  to 
  be 
  noticed 
  that 
  nothing 
  is 
  said 
  of 
  any 
  difference 
  in 
  age 
  

   between 
  these 
  drift 
  heaps 
  and 
  those 
  of 
  the 
  great 
  moraine. 
  

   There 
  is 
  no 
  difference, 
  in 
  fact, 
  and 
  as 
  the 
  writer 
  was 
  happy 
  in 
  

   finding 
  glaciated 
  stones 
  at 
  Lewistown, 
  he 
  set 
  the 
  deposit 
  down 
  

   as 
  a 
  recent 
  glacial 
  formation, 
  and 
  as 
  recent 
  as 
  the 
  glacial 
  gravels 
  

   of 
  the 
  upper 
  Susquehanna. 
  

  

  A 
  glance 
  at 
  the 
  map 
  of 
  Lewis 
  and 
  Wright 
  shows 
  that 
  the 
  

   terminal 
  moraine 
  approaches 
  quite 
  near 
  the 
  north 
  branch 
  of 
  

   the 
  Susquehanna 
  at 
  Williamsport. 
  As 
  the 
  width 
  of 
  the 
  extra- 
  

   morainic 
  deposits 
  will 
  average 
  25 
  miles, 
  the 
  writer 
  saw, 
  when 
  

   he 
  reached 
  the 
  latter 
  place, 
  that 
  Bald 
  Eagle 
  Mountain, 
  rising 
  

   sharply 
  1200 
  feet 
  above 
  the 
  river, 
  must 
  have 
  required 
  a 
  great 
  

   thickness 
  of 
  ice 
  to 
  have 
  been 
  surmounted, 
  and 
  must 
  have 
  

   formed 
  a 
  glacial 
  lake 
  similar 
  to 
  that 
  in 
  the 
  Lehigh 
  valley, 
  as 
  

   has 
  been 
  described 
  by 
  the 
  writer. 
  In 
  proof 
  of 
  this 
  the 
  surface 
  

   deposits 
  west 
  of 
  Muncy 
  changed 
  to 
  slack 
  water 
  clays 
  and 
  over- 
  

   laid, 
  where 
  visible, 
  modified 
  and 
  unmodified 
  drift. 
  A 
  trip 
  

   through 
  the 
  gap 
  in 
  Bald 
  Eagle 
  JVIt., 
  to 
  the 
  inner 
  summit 
  of 
  

   White 
  Deer 
  Mt., 
  lying 
  three 
  miles 
  to 
  the 
  south, 
  and 
  making 
  a 
  

   loop 
  with 
  the 
  former 
  where 
  they 
  meet 
  the 
  Susquehanna, 
  

   showed 
  that 
  ice 
  had 
  surmounted 
  both, 
  and, 
  as 
  the 
  glacier 
  had 
  

   crossed 
  the 
  main 
  Susquehanna 
  at 
  Fisher's 
  Ferry, 
  at 
  the 
  northern 
  

   slope 
  of 
  Little 
  Mt., 
  there 
  was 
  at 
  least 
  fifty 
  miles 
  of 
  the 
  bed 
  on 
  

   the 
  stream 
  covered 
  with 
  ice 
  over 
  1200 
  feet 
  thick. 
  Previous 
  to 
  

   this 
  a 
  line 
  of 
  glacial 
  discharge 
  had 
  been 
  traced 
  up 
  Penn's 
  

   Creek 
  to 
  Paddy 
  Mountain 
  ; 
  but 
  its 
  origin 
  was 
  unknown. 
  

  

  Going 
  west 
  up 
  the 
  valley 
  of 
  the 
  north 
  branch 
  of 
  the 
  Susque- 
  

   hanna, 
  a 
  great 
  slack 
  water 
  terrace 
  150-170 
  feet 
  high 
  was 
  found 
  

   opposite 
  Jersey 
  Shore, 
  which 
  causes 
  the 
  river 
  to 
  make 
  a 
  long 
  

   bend 
  to 
  the 
  north 
  and 
  east. 
  This 
  was 
  formed 
  by 
  a 
  torrential 
  

   discharge 
  of 
  glacial 
  origin 
  from 
  Nippenose 
  valley 
  through 
  

   Anti's 
  gap 
  in 
  Bald 
  Eagle 
  Mt. 
  Rogers 
  has 
  called 
  attention 
  to 
  

   the 
  peculiar 
  features 
  of 
  the 
  erosion 
  of 
  the 
  south 
  side 
  of 
  this 
  

   valley, 
  and 
  to 
  the 
  "drift 
  hill" 
  in 
  the 
  gap. 
  He 
  also 
  notes 
  a 
  

   similar 
  hill 
  in 
  Washington 
  gap 
  between 
  Sugar 
  and 
  dittany 
  

   valleys. 
  The 
  Jersey 
  Shore 
  terrace 
  surprised 
  the 
  writer 
  by 
  

   bending 
  to 
  the 
  northwest, 
  and 
  the 
  stream 
  that 
  drains 
  Nippe- 
  

   nose 
  valley 
  was 
  also 
  surprising 
  in 
  meeting 
  the 
  Susquehanna 
  in 
  

   a 
  similar 
  way, 
  or 
  against 
  the 
  present 
  flow 
  of 
  the 
  river. 
  Both 
  

   pointed 
  to 
  a 
  flow 
  westward. 
  A 
  glance 
  at 
  the 
  map 
  showed 
  that 
  

   the 
  Bald 
  Eagle 
  and 
  Kittany 
  valleys 
  would 
  afford 
  an 
  exit 
  to 
  

   deep 
  waters, 
  and 
  the 
  latter 
  valley 
  was 
  first 
  studied 
  with 
  the 
  

   result 
  that 
  no 
  signs 
  of 
  ice 
  occupation 
  were 
  found 
  ; 
  but 
  it 
  was 
  

   seen 
  that 
  Sugar 
  and 
  Brush 
  valleys 
  had 
  their 
  eastern 
  ends 
  cov- 
  

   ered 
  with 
  ice, 
  and 
  that 
  the 
  northern 
  end 
  of 
  Nittany 
  valley 
  was 
  

   covered 
  deeply 
  with 
  bowlder 
  trash, 
  as 
  was 
  the 
  part 
  adjacent 
  to 
  

   the 
  gaps 
  from 
  the 
  valleys 
  to 
  the 
  east. 
  From 
  Bellefonte 
  east- 
  

  

  