﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  465 
  

  

  Still 
  farther 
  to 
  the 
  north 
  about 
  one 
  fourth 
  of 
  a 
  mile 
  is 
  Nor- 
  

   cross 
  Bros, 
  quarry. 
  The 
  rock 
  is 
  similar 
  in 
  character 
  to 
  the 
  pre- 
  

   ceding 
  but 
  the 
  quarry 
  is 
  smaller. 
  

  

  Two 
  analyses 
  have 
  been 
  given 
  of 
  the 
  stone. 
  No. 
  1 
  was 
  made 
  

   by 
  Prof. 
  Thomas 
  Egleston 
  and 
  no. 
  2 
  by 
  the 
  writer. 
  

  

  Insoluble 
  

  

  Lime 
  

  

  Magnesia 
  21 
  . 
  25 
  

  

  Carbonic 
  acid 
  , 
  

  

  Ferric 
  oxid 
  

  

  Water 
  

  

  Silica 
  

  

  Alumina 
  

  

  Loss 
  

  

  100.00 
  99.75 
  

  

  The 
  quarry 
  at 
  Pleasantville 
  is 
  the 
  largest 
  in 
  Westchester 
  co. 
  

   It 
  is 
  operated 
  by 
  O'Connell 
  & 
  Hillery, 
  successors 
  to 
  the 
  Cornell 
  

   lime 
  co. 
  The 
  limestone 
  is 
  very 
  uniform 
  in 
  its 
  character 
  and 
  on 
  

   account 
  of 
  its 
  white 
  color 
  and 
  coarsely 
  crystalline 
  character 
  has 
  

   been 
  called 
  " 
  snowflake 
  marble." 
  Nearly 
  the 
  entire 
  production 
  of 
  

   this 
  quarry 
  is 
  used 
  for 
  the 
  manufacture 
  of 
  marble 
  dust. 
  The 
  

   composition 
  of 
  the 
  rock 
  according 
  to 
  an 
  analysis 
  given 
  in 
  the 
  

   16th 
  annual 
  report 
  of 
  the 
  United 
  States 
  geological 
  survey, 
  pt 
  3, 
  

   p. 
  468 
  is 
  as 
  follows: 
  

  

  Lime 
  carbonate 
  54 
  . 
  62 
  

  

  Magnesia 
  carbonate 
  45 
  . 
  04 
  

  

  Iron 
  carbonate 
  .16 
  

  

  Alumina 
  .07 
  

  

  Silica 
  ' 
  .10 
  

  

  1 
  

  

  2 
  

  

  

  1.33 
  

  

  30.16 
  

  

  30.68 
  

  

  21.25 
  

  

  20.71 
  

  

  47.30 
  

  

  46.66 
  

  

  .21 
  

  

  .21 
  

  

  .02 
  

  

  .16 
  

  

  .24 
  

  

  

  .19 
  

  

  

  .63 
  

  

  

  99.99 
  

  

  