﻿466 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  This 
  does 
  not 
  quite 
  agree 
  with 
  an 
  analysis 
  made 
  by 
  the 
  writer 
  

   which 
  represents 
  an 
  average 
  of 
  the 
  quarry 
  as 
  follows 
  : 
  

  

  Lime 
  carbonate 
  59 
  . 
  84 
  

  

  Magnesia 
  carbonate 
  36 
  . 
  80 
  

  

  Alumina 
  .40 
  

  

  Ferric 
  oxid 
  .25 
  

  

  Silica 
  2.31 
  

  

  99.60 
  

  

  A 
  small 
  quarry 
  was 
  once 
  in 
  operation 
  near 
  Scarsdale, 
  West- 
  

   chester 
  co. 
  but 
  the 
  rock 
  contains 
  considerable 
  mineral 
  impurities. 
  

   The 
  crystalline 
  limestone 
  extends 
  up 
  the 
  valley 
  of 
  Anns 
  cove, 
  

   and 
  Sprout 
  brook 
  for 
  several 
  miles, 
  and 
  is 
  exposed 
  at 
  a 
  number 
  

   of 
  places, 
  specially 
  along 
  the 
  line 
  of 
  the 
  narrow 
  gage 
  railroad 
  

   leading 
  up 
  to 
  the 
  Edison 
  magnetic 
  mines. 
  The 
  best 
  exposure 
  of 
  

   this 
  is 
  in 
  the 
  quarry 
  one 
  and 
  three 
  fourths 
  miles 
  west 
  of 
  Peekskill 
  

   rock. 
  The 
  rock 
  is 
  a 
  fine 
  grained, 
  grayish 
  white 
  stone, 
  which 
  seems 
  

   to 
  be 
  the 
  better 
  quality 
  towards 
  the 
  eastern 
  end 
  of 
  the 
  mine 
  where 
  

   it 
  is 
  of 
  a 
  darker 
  color. 
  The 
  working 
  face 
  exposed 
  is 
  over 
  75 
  feet 
  

   long. 
  The 
  following 
  analysis 
  made 
  by 
  J. 
  D. 
  Irving 
  shows 
  the 
  com- 
  

   position 
  of 
  the 
  stone, 
  and 
  illustrates 
  the 
  point 
  that 
  far 
  less 
  mag- 
  

   nesia 
  exists 
  in 
  this 
  limestone 
  than 
  is 
  found 
  in 
  other 
  portions 
  of 
  

   Westchester 
  co. 
  The 
  rock 
  was 
  formerly 
  quarried 
  for 
  blast 
  furnace 
  

   flux. 
  

  

  Silica 
  2.50 
  

  

  Ferric 
  oxid 
  and 
  alumina 
  1 
  . 
  55 
  

  

  Lime 
  carbonate 
  81.64 
  

  

  Magnesia 
  carbonate 
  13 
  . 
  50 
  

  

  99.19 
  

  

  Other 
  exposures 
  of 
  this 
  same 
  rock 
  outcrop, 
  as 
  low 
  ledges 
  on 
  

   the 
  property 
  of 
  Mr 
  Higgins 
  about 
  two 
  and 
  one 
  half 
  miles 
  west 
  of 
  

   Peekskill 
  village. 
  Some 
  of 
  these 
  ledges 
  show 
  a 
  stone 
  of 
  consider- 
  

   able 
  purity 
  while 
  in 
  others 
  the 
  rock 
  is 
  rather 
  micaceous. 
  

  

  