﻿846 
  

  

  NEW 
  YOEK 
  STATE 
  MUSEUM 
  

  

  mixture 
  then 
  burned 
  in 
  suitable 
  kilns 
  at 
  a 
  bigber 
  temperature 
  tban 
  

   tbat 
  arrived 
  at 
  in 
  tbe 
  manufacture 
  of 
  any 
  except 
  tbe 
  most 
  refractory 
  

   grades 
  of 
  clay 
  products 
  proper, 
  tbe 
  object 
  of 
  tbe 
  burning 
  being 
  to 
  

   cause 
  tbe 
  component 
  elements 
  of 
  tbe 
  mass 
  to 
  unite 
  — 
  for 
  wbicb 
  

   reason 
  tbe 
  material 
  in 
  burning 
  bas 
  to 
  be 
  brougbt 
  to 
  a 
  condition 
  

   of 
  sintering 
  — 
  tbe 
  new 
  compounds 
  being 
  calcic 
  silicates 
  and 
  calcic 
  

   aluminates. 
  Tbe 
  burned 
  mass 
  is 
  tben 
  finely 
  ground, 
  after 
  wbicb 
  

   most 
  of 
  it 
  will 
  pass 
  tbrougb 
  a 
  100' 
  mesb 
  sieve, 
  and 
  a 
  large 
  percentage 
  

   of 
  it 
  tbrougb 
  200 
  mesb, 
  as 
  well. 
  Tbis 
  ground 
  material 
  wben 
  mixed 
  

   witb 
  water 
  bas 
  excellent 
  bydraulic 
  properties, 
  tbe 
  mass 
  setting 
  into 
  

   a 
  stonelike 
  condition. 
  It 
  bas 
  been 
  found 
  by 
  JSTewberry 
  tbat 
  in 
  tbe 
  

   best 
  cements 
  tbe 
  percentage 
  of 
  lime 
  is 
  equal 
  to 
  2.8 
  times 
  tbe 
  silica 
  

   plus 
  1.1 
  times 
  tbe 
  alumina. 
  

  

  New 
  York, 
  witb. 
  ber 
  great 
  series 
  of 
  Paleozoic 
  limestoiOje 
  forma- 
  

   tions, 
  ber 
  Quaternary 
  marls, 
  and 
  ber 
  clays 
  and 
  sbales 
  ranging 
  in 
  

   age 
  from 
  tbe 
  Silurian 
  to 
  tbe 
  Quaternary, 
  is 
  liberally 
  supplied 
  with 
  

   raw 
  materials 
  to 
  support 
  a 
  flourisbing 
  portland 
  cement 
  industry, 
  

   and 
  indeed 
  tbere 
  are 
  already 
  seven 
  factories 
  in 
  operation 
  in 
  tbe 
  

   state, 
  wbile 
  an 
  eigbtb 
  one 
  is 
  nearly 
  completed, 
  and 
  several 
  more 
  

   are 
  in 
  contemplation. 
  

  

  Tbe 
  characters 
  of 
  the 
  different 
  limestone 
  formations 
  are 
  discussed 
  

   in 
  the 
  bulletin 
  already 
  referred 
  to, 
  and 
  an 
  idea 
  of 
  the 
  nature 
  of 
  the 
  

   clays 
  and 
  shales 
  can 
  be 
  gained 
  from 
  the 
  analyses 
  given 
  in 
  different 
  

   portions 
  of 
  tbis 
  bulletin. 
  For 
  farther 
  reference 
  tbere 
  are 
  given 
  

   herewith 
  some 
  additional 
  analyses 
  of 
  clays 
  and 
  shales 
  used 
  at 
  differ- 
  

   ent 
  localities 
  in 
  the 
  United 
  States 
  for 
  the 
  manufacture 
  of 
  portland 
  

   cement. 
  

  

  Up 
  to 
  a 
  few 
  years 
  ago 
  most 
  of 
  the 
  portland 
  cement 
  used 
  in 
  the 
  

   United 
  States 
  was 
  imported 
  from 
  foreign 
  countries, 
  but 
  at 
  the 
  

   present 
  time 
  it 
  is 
  being 
  found 
  that 
  it 
  is 
  possible 
  to 
  make 
  just 
  as 
  good 
  

   hydraulic 
  cement 
  in 
  this 
  country, 
  and 
  the 
  local 
  production, 
  already 
  

   large, 
  is 
  increasing 
  annually, 
  and 
  prejudice 
  against 
  it, 
  which 
  has 
  

   unfortunately 
  existed, 
  is 
  slowly 
  disappearing. 
  

  

  