﻿COHOES 
  MASTODON. 
  141 
  

  

  one 
  to 
  twelve 
  inches 
  in 
  diameter. 
  The 
  depth 
  of 
  basin 
  below 
  the 
  

   upper 
  fall 
  is 
  40-45 
  feet. 
  

  

  Pitted 
  Bock. 
  — 
  In 
  the 
  channel, 
  at 
  the 
  east 
  side 
  and 
  several 
  

   hundred 
  feet 
  below 
  the 
  basin 
  of 
  the 
  fall, 
  is 
  a 
  mass 
  of 
  rock 
  in 
  

   place, 
  ten 
  or 
  fifteen 
  feet 
  long, 
  hollowed 
  out 
  and 
  pitted 
  over 
  its 
  

   entire 
  surface, 
  as 
  though 
  being 
  dissolved 
  by 
  water. 
  Its 
  texture 
  

   is 
  that 
  of 
  the 
  concretionary 
  masses. 
  A 
  specimen 
  was 
  collected. 
  

  

  Terraces. 
  — 
  I 
  have 
  recently 
  walked 
  (May, 
  18(38) 
  from 
  the 
  

   Patroon's 
  up 
  the 
  Shakers' 
  road 
  nearly 
  to 
  the 
  Shakers' 
  settlement, 
  

   and 
  thence 
  to 
  the 
  Mohawk 
  near 
  Shakers' 
  Island. 
  After 
  the 
  first 
  

   mile, 
  which 
  was 
  over 
  gravel, 
  I 
  was 
  upon 
  a 
  sand 
  plain 
  varied 
  by 
  

   hills 
  of 
  blown 
  sand, 
  and 
  did 
  not 
  see 
  the 
  clay, 
  though 
  I 
  crossed 
  

   several 
  gulleys. 
  In 
  the 
  bed 
  of 
  a 
  stream 
  near 
  the 
  Mohawk 
  I 
  saw 
  

   gravel, 
  on 
  which 
  the 
  sand 
  seemed 
  to 
  rest 
  immediately. 
  In 
  riding 
  

   to 
  Saratoga, 
  I 
  saw 
  from 
  the 
  cars 
  that 
  the 
  terrace 
  continues 
  

   from 
  Waterford 
  to 
  Mcchanicsville 
  on 
  both 
  sides 
  of 
  the 
  Hudson. 
  

   1 
  was 
  unable 
  to 
  obtain 
  another 
  good 
  view 
  until 
  I 
  reached 
  Ballston, 
  

   from 
  which 
  place 
  to 
  Saratoga 
  the 
  railroad 
  track 
  is 
  laid 
  on 
  a 
  

   terrace 
  of 
  sand 
  resting 
  on 
  clay, 
  which, 
  Dr. 
  Allen 
  told 
  me, 
  

   were 
  continuations 
  of 
  the 
  sand 
  and 
  clay 
  of 
  the 
  Albany 
  terrace. 
  

   With 
  him 
  I 
  examined 
  two 
  sections 
  in 
  Saratoga. 
  One 
  showed 
  

  

  Fine 
  yellow 
  sand. 
  Fine 
  yellow 
  sand. 
  

  

  Red 
  clay. 
  The 
  Other, 
  L-aurentian 
  gravel, 
  little 
  sorted. 
  

  

  Dark, 
  coarse, 
  sorted 
  (Laurentian?) 
  sand. 
  Red 
  clay. 
  

  

  I 
  made 
  no 
  measurement, 
  but 
  observed 
  that 
  the 
  sand 
  is 
  much 
  

   deeper 
  and 
  the 
  clay 
  much 
  thinner 
  than 
  in 
  Albany. 
  Dr. 
  A. 
  says 
  

   blue 
  clay 
  generally 
  underlies 
  the 
  red. 
  

  

  From 
  the 
  Patroon's 
  to 
  the 
  Rural 
  Cemetery 
  I 
  have 
  not 
  observed 
  

   the 
  clay 
  ; 
  from 
  a 
  point 
  not 
  much 
  above 
  the 
  cemetery 
  to 
  Cohoes 
  

   it 
  can 
  be 
  traced 
  by 
  an 
  observer 
  standing 
  on 
  the 
  hill 
  behind 
  Troy. 
  

   From 
  this 
  position 
  I 
  detected 
  a 
  sloping 
  southward 
  of 
  the 
  top 
  of 
  

   the 
  clay 
  terrace, 
  which 
  I 
  was 
  able 
  to 
  verify 
  with 
  a 
  surveyor's 
  level. 
  

   At 
  a 
  point 
  near 
  the 
  West 
  Troy 
  station 
  of 
  the 
  Rensselaer 
  and 
  Sara- 
  

   toga 
  railroad 
  the 
  clay 
  has 
  nearly 
  its 
  Cohoes 
  level, 
  while 
  it 
  is 
  25 
  or 
  

   30 
  feet 
  lower 
  a 
  mile 
  farther 
  south. 
  The 
  clay 
  flanks 
  the 
  east 
  bank 
  

   of 
  the 
  Hudson 
  from 
  Troy 
  to 
  Greenbush. 
  

  

  