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  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  its 
  western 
  margin 
  and 
  surmounted 
  by 
  a 
  plateau 
  and 
  terraces 
  of 
  

   variable 
  width; 
  third, 
  a 
  wide 
  area 
  of 
  high 
  rolling 
  hills 
  and 
  

   terraced 
  ridges 
  presenting 
  a 
  steep 
  front 
  to 
  the 
  plateaus 
  above 
  

   the 
  escarpment. 
  This 
  occupies 
  an 
  area 
  of 
  about 
  175 
  square 
  

   miles, 
  extending 
  to 
  the 
  southwestern 
  corner 
  of 
  the 
  county, 
  where 
  

   ts 
  hills 
  finally 
  merge 
  into 
  the 
  long 
  slope 
  of 
  the 
  northern 
  exten- 
  

   sion 
  of 
  the 
  Catskills. 
  In 
  the 
  northern 
  part 
  of 
  Knox 
  township 
  

   there 
  is 
  a 
  region 
  of 
  hills 
  extending 
  northward 
  from 
  the 
  foot 
  of 
  

   the 
  crest 
  of 
  the 
  great 
  escarpment 
  to 
  Schenectady 
  county, 
  and 
  

   there 
  are 
  some 
  elevations 
  of 
  the 
  same 
  nature 
  in 
  the 
  central 
  part 
  

   of 
  New 
  Scotland 
  township. 
  

  

  The 
  great 
  plain. 
  — 
  The 
  great 
  plain 
  extending 
  from 
  the 
  foot 
  of 
  

   the 
  Helderberg 
  escarpment 
  to 
  the 
  rivers 
  (Hudson 
  and 
  Mohawk) 
  

   presents 
  wide 
  areas 
  of 
  comparatively 
  smooth 
  surface, 
  having 
  

   an 
  altitude 
  sloping 
  gradually 
  from 
  200 
  feet 
  about 
  Coeymans 
  

   Junction 
  to 
  300 
  feet 
  in 
  the 
  northeastern 
  corner 
  of 
  the 
  county 
  

   and 
  400 
  feet 
  toward 
  Altamont. 
  The 
  streams 
  which 
  traverse 
  

   this 
  plain 
  are 
  the 
  Normanskill, 
  Vlaumankill, 
  Coeymans 
  

   creek 
  and 
  Patroon's 
  creek. 
  These 
  streams, 
  and 
  their 
  branches, 
  

   have 
  cut 
  valleys 
  of 
  various 
  kinds, 
  which 
  are 
  in 
  greater 
  part 
  rela- 
  

   tively 
  narrow 
  and 
  steep 
  sided. 
  The 
  plain 
  extends 
  up 
  the 
  Onis- 
  

   kethau 
  and 
  Hannacrois 
  valleys 
  for 
  a 
  considerable 
  distance, 
  and 
  

   up 
  the 
  Boxenkill 
  to 
  a 
  point 
  two 
  miles 
  above 
  Altamont. 
  About 
  

   Wemple 
  the 
  higher 
  plain 
  is 
  separated 
  from 
  the 
  Hudson 
  river 
  by 
  

   a 
  terrace 
  averaging 
  100 
  feet 
  above 
  tide, 
  but 
  in 
  the 
  other 
  parts 
  of 
  

   the 
  region 
  it 
  ends 
  in 
  steep 
  banks 
  bordering 
  the 
  Hudson 
  and 
  

   »Mohawk 
  valleys. 
  These 
  terrace 
  scarps 
  rarely 
  extend 
  to 
  the 
  shore 
  

   of 
  the 
  river, 
  but 
  rise 
  from 
  a 
  low 
  alluvial 
  plain 
  which 
  occupies 
  a 
  

   greater 
  or 
  less 
  width 
  in 
  the 
  bottom 
  of 
  the 
  depressions. 
  The 
  city 
  

   of 
  Albany 
  is 
  built, 
  in 
  greater 
  part, 
  on 
  the 
  slope 
  of 
  this 
  terrace 
  

   scarp, 
  and 
  along 
  the 
  low 
  narrow 
  terrace 
  at 
  its 
  base. 
  The 
  upper 
  

   part 
  of 
  the 
  city 
  is 
  on 
  the 
  high 
  plain, 
  at 
  an 
  altitude 
  of 
  from 
  180 
  

   to 
  240 
  feet 
  above 
  the 
  river. 
  The 
  surface 
  of 
  the 
  great 
  plain 
  is 
  

   diversified 
  by 
  a 
  considerable 
  number 
  of 
  hills 
  and 
  ridges 
  rising 
  

   above 
  its 
  surface. 
  The 
  more 
  conspicuous 
  of 
  these 
  are 
  located 
  

   mainly 
  north 
  of 
  the 
  latitude 
  of 
  Albany, 
  where 
  they 
  are 
  scattered 
  

   about 
  irregularly, 
  and 
  give 
  rise 
  to 
  a 
  peculiarly 
  knolly 
  topography. 
  

   They 
  seldom 
  rise 
  more 
  than 
  fifty 
  feet 
  above 
  the 
  general 
  plain, 
  

  

  