﻿148 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Lake 
  Champlain: 
  it 
  is 
  a 
  fine 
  grained, 
  gray, 
  brittle, 
  limestone, 
  30 
  

   feet 
  in 
  its 
  greatest 
  thickness: 
  and 
  the 
  most 
  conspicuous 
  of 
  its 
  

   fossils 
  is 
  one 
  of 
  which 
  the 
  nature 
  is 
  somewhat 
  obscure, 
  but 
  which 
  

   was 
  regarded 
  as 
  the 
  stem 
  of 
  some 
  marine 
  plant. 
  

  

  Standing 
  in 
  an 
  upright 
  position, 
  perpendicular 
  to 
  the 
  strata 
  the 
  

   ends 
  of 
  the 
  stems 
  are 
  seen 
  on 
  the 
  surface 
  of 
  the 
  layers, 
  to 
  which 
  

   they 
  give 
  a 
  peculiar 
  dotted 
  appearance, 
  from 
  which 
  the 
  rock 
  has 
  

   derived 
  its 
  name, 
  and 
  by 
  which, 
  as 
  well 
  as 
  by 
  its 
  characteristic 
  

   color 
  and 
  fracture, 
  it 
  is 
  easily 
  recognized. 
  It 
  is 
  a 
  valuable 
  rock 
  

   for 
  economical 
  uses, 
  as 
  it 
  is 
  a 
  good 
  building 
  stone, 
  and 
  dresses 
  well 
  

   under 
  the 
  chisel 
  ; 
  it 
  is 
  quarried 
  to 
  a 
  considerable 
  extent 
  at 
  various 
  

   points 
  in 
  the 
  Mohawk 
  valley. 
  

  

  Black 
  River 
  Limestone 
  

  

  To 
  the 
  Birdseye 
  limestone 
  succeeds 
  a 
  thin 
  mass, 
  amounting 
  in 
  

   all 
  to 
  only 
  10 
  or 
  12 
  feet, 
  but 
  classed 
  as 
  a 
  distinct 
  rock 
  from 
  having 
  

   a 
  somewhat 
  peculiar 
  mineral 
  character 
  and 
  containing 
  a 
  peculiar 
  

   set 
  of 
  fossils. 
  It 
  is 
  a 
  dark, 
  thick-bedded, 
  compact, 
  hard 
  limestone^ 
  

   fine 
  grained 
  and 
  taking 
  a 
  high 
  polish, 
  and 
  is 
  worked 
  as 
  a 
  black 
  

   marble 
  at 
  Glens 
  Falls 
  on 
  the 
  Hudson 
  river, 
  and 
  at 
  Isle 
  La 
  Motte 
  

   on 
  Lake 
  Champlain. 
  It 
  is 
  also 
  well 
  seen 
  at 
  Watertown, 
  Jefferson 
  

   county, 
  in 
  the 
  banks 
  of 
  the 
  Black 
  river 
  from 
  which 
  locality 
  it 
  has 
  

   been 
  named. 
  

  

  In 
  the 
  last 
  place 
  it 
  is 
  lumpy 
  and 
  irregular 
  in 
  texture, 
  and 
  not 
  fit 
  

   for 
  good 
  masonry 
  or 
  marble; 
  and 
  is 
  known 
  among 
  quarrymen 
  as 
  

   ^ 
  the 
  seven 
  foot 
  tier.' 
  In 
  the 
  Mohawk 
  valley 
  it 
  seems 
  to 
  have 
  been 
  

   deposited 
  in 
  only 
  a 
  few 
  places, 
  the 
  Birdseye 
  being 
  generally 
  

   covered 
  directly 
  by 
  the 
  Trenton. 
  

  

  Trenton 
  Limestone 
  

  

  Above 
  the 
  Black 
  river 
  limestone 
  (or 
  where 
  this 
  is 
  absent, 
  lying 
  

   upon 
  the 
  Birdseye), 
  is 
  one 
  of 
  the 
  most 
  interesting 
  repositories 
  of 
  

   organic 
  remains 
  in 
  the 
  state; 
  a 
  thick 
  group 
  of 
  limestone 
  strata, 
  

   usually 
  black 
  and 
  fine 
  grained 
  with 
  seams 
  of 
  slate 
  toward 
  the 
  

   lower 
  part, 
  but 
  gray 
  and 
  crystalline 
  near 
  the 
  top. 
  

  

  