﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  421 
  

  

  the 
  raw 
  materials 
  and 
  to 
  perfect 
  an 
  intimate 
  mixture 
  of 
  them 
  are 
  

   the 
  prime 
  factors 
  in 
  making 
  good 
  portland 
  cement. 
  Other 
  things 
  

   being 
  equal 
  the 
  more 
  exactly 
  the 
  proportions 
  are 
  maintained 
  the 
  

   greater 
  the 
  uniformity 
  of 
  the 
  cement, 
  the 
  more 
  homogeneous 
  the 
  

   mixture 
  and 
  the 
  finer 
  the 
  state 
  of 
  division 
  of 
  its 
  particles 
  the 
  

   greater 
  the 
  strength 
  and 
  hydraulic 
  energy 
  of 
  the 
  product." 
  Ad- 
  

   mitting 
  these 
  points 
  as 
  axiomatic 
  there 
  is 
  yet 
  of 
  course 
  a 
  practi- 
  

   cal 
  limit 
  in 
  cost 
  of 
  preparing 
  raw 
  materials 
  which 
  can 
  not 
  be 
  

   exceeded 
  in 
  successful 
  manufacture. 
  It 
  is 
  thus 
  necessary 
  to 
  

   achieve 
  on 
  a 
  commercial 
  basis 
  as 
  perfect 
  a 
  mixture 
  as 
  may 
  be. 
  

   In 
  dealing 
  with 
  so 
  many 
  different 
  grades 
  of 
  raw 
  material 
  there 
  

   is 
  here 
  an 
  opportunity 
  for 
  the 
  exercise 
  of 
  intelligent 
  adaptation 
  

   of 
  plant 
  to 
  conditions. 
  At 
  the 
  same 
  cost 
  very 
  different 
  results 
  

   may 
  be 
  obtained 
  from 
  different 
  apparatus. 
  Indeed 
  in 
  this 
  whole 
  

   matter 
  of 
  handling 
  raw 
  materials 
  technical 
  skill 
  finds 
  an 
  ample 
  

   field 
  both 
  in 
  accounting 
  for 
  and 
  proportioning 
  mixtures 
  and 
  its 
  

   adaptation 
  of 
  plant. 
  It 
  may 
  be 
  frankly 
  admitted 
  that 
  in 
  this 
  

   respect 
  representative 
  American 
  manufacturers 
  are 
  not 
  yet 
  on 
  a 
  

   par 
  with 
  similar 
  French 
  and 
  jGerman 
  works. 
  In 
  laboratory 
  

   facilities 
  and 
  in 
  executive 
  staff 
  European 
  works 
  are 
  superior. 
  

   The 
  chemist 
  occupies 
  there 
  an 
  assured 
  and 
  responsible 
  position 
  

   which 
  he 
  has 
  not 
  yet 
  been 
  accorded 
  here. 
  In 
  the 
  general 
  

   excellence 
  of 
  plant 
  per 
  se, 
  however, 
  American 
  works 
  are 
  now 
  

   quite 
  on 
  a 
  par 
  class 
  for 
  class 
  with 
  those 
  of 
  continental 
  Europe. 
  

  

  The 
  simplest 
  method 
  of 
  preparing 
  raw 
  materials 
  in 
  American 
  

   practice 
  is 
  that 
  in 
  use 
  for 
  the 
  hard, 
  dry 
  raw 
  materials 
  of 
  the 
  

   Lehigh 
  valley, 
  which 
  are 
  burned 
  in 
  revolving 
  kilns. 
  It 
  consists 
  

   in 
  reducing 
  a 
  suitable 
  mixture 
  of 
  rock 
  to 
  a 
  fine 
  powder. 
  This 
  

   powder 
  is 
  fed 
  continuously 
  into 
  the 
  upper 
  end 
  of 
  the 
  kiln 
  and 
  is 
  

   carried 
  forward 
  and 
  downward 
  towards 
  the 
  fire 
  by 
  the 
  revolution 
  

   of 
  the 
  inclined 
  cylinder, 
  emerging 
  as 
  clinker 
  from 
  the 
  lower 
  end. 
  

   There 
  is 
  no 
  preparation 
  of 
  raw 
  materials 
  anywhere 
  in 
  the 
  world 
  

   so 
  simple 
  and 
  inexpensive. 
  The 
  revolving 
  kiln 
  first 
  became 
  a 
  

   commercial 
  success 
  with 
  this 
  class 
  of 
  material 
  in 
  eastern 
  Penn- 
  

   sylvania, 
  and 
  undoubtedly 
  it 
  is 
  with 
  these 
  argillaceous 
  lime- 
  

   stones 
  that 
  it 
  can 
  be 
  employed 
  most 
  advantageously. 
  

  

  