﻿EXPLANATION 
  OF 
  PLATES 
  

  

  RELATING 
  TO 
  THE 
  COHOES 
  MASTODON. 
  

  

  PLATE 
  I. 
  

  

  A 
  map 
  (on 
  a 
  scale 
  of 
  about 
  two 
  miles 
  to 
  the 
  inch), 
  showing 
  the 
  junction 
  of 
  the 
  

   Mohawk 
  and 
  Hudson 
  rivers, 
  with 
  the 
  position 
  and 
  relation 
  of 
  the 
  principal 
  places 
  

   referred 
  to 
  in 
  the 
  article 
  on 
  the 
  Cohoes 
  mastodon. 
  

  

  PLATE 
  II. 
  

  

  No. 
  1. 
  A 
  section 
  across 
  the 
  Mohawk 
  valley, 
  one 
  mile 
  below 
  Crescent, 
  showing 
  

   the 
  outline 
  of 
  the 
  valley 
  and 
  the 
  relations 
  of 
  the 
  drift 
  or 
  gravel 
  beds, 
  the 
  estuary 
  

   clay 
  and 
  the 
  alluvium 
  of 
  the 
  valley. 
  

  

  The 
  lower 
  part 
  of 
  the 
  drift, 
  in 
  this 
  and 
  the 
  other 
  sections, 
  is 
  of 
  glacial 
  origin, 
  

   resting 
  upon 
  the 
  striated 
  and 
  smoothed 
  surfaces 
  of 
  the 
  rock. 
  The 
  upper 
  portion 
  

   of 
  the 
  drift 
  is 
  water-worn, 
  and 
  more 
  or 
  less 
  sorted 
  and 
  stratified 
  by 
  the 
  action 
  of 
  

   water. 
  

  

  No. 
  2. 
  Section 
  across 
  the 
  valley, 
  opposite 
  the 
  Harmony 
  mills, 
  showing 
  the 
  deep, 
  

   nearly 
  vertically 
  walled 
  channel 
  below 
  the 
  falls 
  ; 
  with 
  a 
  narrow, 
  deeper 
  channel 
  in 
  

   the 
  center, 
  which 
  is 
  the 
  only 
  part 
  occupied 
  by 
  water 
  during 
  the 
  dry 
  season. 
  

  

  Two 
  sections 
  of 
  ancient 
  pot-holes 
  are 
  shown 
  in 
  the 
  slate 
  rock 
  on 
  the 
  east 
  side 
  

   of 
  the 
  river. 
  

  

  No. 
  3. 
  Longitudinal 
  section 
  of 
  the 
  river 
  bed 
  along 
  the 
  main 
  channel 
  from 
  oppo- 
  

   site 
  the 
  Harmony 
  mills 
  to 
  the 
  basin 
  of 
  deep 
  water 
  above 
  the 
  falls. 
  The 
  basin 
  of 
  

   deep 
  water 
  below 
  the 
  falls 
  communicates 
  with 
  the 
  narrow, 
  deep 
  channel 
  in 
  section 
  

   No. 
  2, 
  in 
  the 
  middle 
  of 
  the 
  river 
  bed 
  ; 
  and 
  also 
  on 
  Plate 
  iii 
  along 
  the 
  center 
  of 
  

   the 
  river 
  channel. 
  

  

  PLATE 
  III. 
  

  

  A 
  map 
  reduced 
  from 
  a 
  large 
  working 
  map 
  (4x9 
  feet), 
  now 
  in 
  the 
  State 
  Museum, 
  

   upon 
  which 
  all 
  the 
  observations 
  of 
  the 
  survey 
  were 
  recorded. 
  

  

  For 
  the 
  explanation 
  of 
  the 
  figures 
  in 
  the 
  river 
  channel, 
  and 
  the 
  different 
  repre- 
  

   sentations 
  of 
  the 
  pot-holes, 
  see 
  explanations 
  above 
  the 
  title. 
  

  

  