﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  379 
  

  

  In 
  burning 
  it 
  is 
  important 
  to 
  observe 
  that 
  the 
  temperature 
  re- 
  

   mains 
  as 
  constant 
  as 
  possible 
  and 
  varies 
  only 
  between 
  certain 
  

   limits. 
  When 
  limestone 
  is 
  overburned, 
  the 
  lime 
  made 
  from 
  it 
  

   slakes 
  slowly 
  and 
  incompletely. 
  In 
  the 
  case 
  of 
  limerock 
  with 
  

   clayey 
  impurities 
  a 
  sintering 
  is 
  very 
  apt 
  to 
  occur 
  and 
  this 
  should 
  

   in 
  all 
  cases 
  be 
  strictly 
  avoided. 
  

  

  It 
  is 
  true 
  that 
  the 
  higher 
  the 
  temperature 
  is 
  within 
  the 
  per- 
  

   missible 
  limits 
  the 
  denser 
  will 
  be 
  the 
  lime. 
  On 
  the 
  other 
  hand 
  

   the 
  temperature 
  must 
  not 
  get 
  too 
  low, 
  as 
  in 
  this 
  case 
  any 
  large 
  

   pieces 
  of 
  limestone 
  that 
  may 
  be 
  in 
  the 
  kiln 
  will 
  not 
  become 
  

   thoroughly 
  burned. 
  The 
  unburned 
  core 
  resulting 
  from 
  under- 
  

   burning 
  makes 
  the 
  lime 
  lean. 
  To 
  avoid 
  such 
  an 
  occurrence 
  as 
  

   far 
  as 
  possible 
  it 
  is 
  advisable 
  not 
  to 
  put 
  too 
  large 
  pieces 
  into 
  

   the 
  kiln. 
  

  

  The 
  burning 
  should 
  proceed 
  as 
  rapidly 
  as 
  possible 
  for 
  if 
  the 
  

   limestone 
  is 
  subjected 
  too 
  long 
  to 
  the 
  highest 
  heat 
  of 
  the 
  kiln 
  the 
  

   lime 
  will 
  be 
  of 
  inferior 
  quality 
  and 
  will 
  slake 
  more 
  slowly. 
  

  

  Limestone 
  begins 
  to 
  lose 
  its 
  carbonic 
  acid 
  gas 
  at 
  about 
  750° 
  

   F. 
  but 
  all 
  of 
  it 
  does 
  not 
  pass 
  off 
  probably 
  till 
  the 
  temperature 
  

   of 
  1300° 
  to 
  1400° 
  F. 
  is 
  reached. 
  

  

  Limestone 
  should 
  never 
  be 
  burned 
  with 
  a 
  coal 
  running 
  high 
  in 
  

   sulfur 
  as 
  the 
  latter 
  unites 
  readily 
  with 
  the 
  lime 
  forming 
  cal- 
  

   cium 
  sulfate. 
  

  

  This 
  sulfate 
  of 
  lime 
  reacts 
  subsequently 
  with 
  the 
  aid 
  of 
  

   moisture 
  on 
  any 
  alkalies 
  that 
  may 
  be 
  present, 
  with 
  the 
  formation 
  

   of 
  alkaline 
  sulfates, 
  which 
  being 
  soluble 
  are 
  often 
  brought 
  to 
  

   the 
  surface 
  after 
  the 
  lime 
  is 
  in 
  the 
  wall 
  and 
  cause 
  the 
  unsightly 
  

   white 
  coatings 
  on 
  bricks. 
  

  

  The 
  lime 
  thus 
  obtained 
  by 
  the 
  burning 
  of 
  limestone 
  is 
  a 
  

   white, 
  amorphous, 
  more 
  or 
  less 
  dense 
  mass 
  with 
  a 
  specific 
  

   gravity 
  of 
  3.09. 
  It 
  is 
  infusible. 
  Lime 
  weighs 
  from 
  1400 
  to 
  1800 
  

   lb. 
  a 
  cubic 
  meter, 
  the 
  variation 
  in 
  weight 
  depending 
  on 
  the 
  

   density 
  of 
  the 
  original 
  rock 
  and 
  the 
  degree 
  to 
  which 
  it 
  has 
  been 
  

   burned. 
  Dense 
  stone 
  gives 
  a 
  denser 
  lime. 
  

  

  Quicklime 
  is 
  a 
  strong 
  base 
  and 
  absorbs 
  water 
  with 
  the 
  great- 
  

   est 
  avidity. 
  In 
  water 
  it 
  forms 
  a 
  milky 
  liquid 
  known 
  as 
  milk 
  of 
  

   lime. 
  

  

  