﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  463 
  

  

  A 
  number 
  of 
  samples 
  were 
  collected 
  from 
  Marks's 
  quarry 
  and 
  

   their 
  average 
  composition 
  is 
  as 
  follows: 
  

  

  Silica 
  98 
  

  

  Ferric 
  oxid 
  .30 
  

  

  Alumina 
  .84 
  

  

  Lime 
  '. 
  . 
  31.40 
  

  

  Magnesia 
  16.96 
  

  

  This 
  it 
  will 
  be 
  noticed 
  represents 
  a 
  high 
  grade 
  of 
  magnesian 
  

   limestone 
  running 
  very 
  low 
  in 
  silica 
  and 
  probably 
  suitable 
  for 
  

   the 
  lining 
  of 
  Bessemer 
  converters. 
  There 
  are 
  certain 
  layers 
  in 
  

   the 
  quarry 
  which 
  have 
  a 
  tendency 
  to 
  become 
  siliceous 
  in 
  their 
  

   character 
  and 
  these 
  have 
  to 
  be 
  avoided 
  in 
  mining. 
  

  

  The 
  rock 
  from 
  Marks' 
  s 
  quarry 
  has 
  been 
  shipped 
  to 
  Newark 
  for 
  

   a 
  number 
  of 
  years 
  to 
  be 
  used 
  as 
  flux. 
  In 
  this 
  case 
  the 
  sorting 
  

   was 
  probably 
  not 
  as 
  careful 
  as 
  it 
  would 
  have 
  been 
  for 
  some 
  pur- 
  

   poses, 
  and 
  consequently 
  the 
  following 
  series 
  of 
  analyses 
  kindly 
  

   furnished 
  by 
  Mr 
  G. 
  H. 
  Stone 
  of 
  the 
  New 
  Jersey 
  zinc 
  and 
  iron 
  co. 
  

   show 
  a 
  greater 
  silica 
  contents: 
  

  

  Silica 
  6.77 
  5.94 
  5.12 
  2.05 
  

  

  Ferric0XJd 
  i 
  1.81 
  2.82 
  .75 
  '" 
  

  

  Alumina 
  J 
  1.11 
  

  

  Lime 
  45.02 
  29.05 
  25.42 
  34.63 
  

  

  Magnesia 
  3.16 
  20.05 
  22.35 
  15.37 
  

  

  Phosphoric 
  acid 
  027 
  

  

  Carbon 
  dioxid 
  44 
  . 
  11 
  

  

  The 
  good 
  rock 
  of 
  the 
  Sing 
  Sing 
  lime 
  co. 
  shows 
  even 
  less 
  silica 
  

   than 
  that 
  from 
  Marks's 
  quarry 
  as 
  will 
  be 
  seen 
  from 
  the 
  following 
  

   analysis: 
  

  

  Silica 
  .87 
  

  

  Ferric 
  oxid 
  .25 
  

  

  Alumina 
  .57 
  

  

  Lime 
  31.40 
  

  

  Magnesia 
  19.95 
  

  

  