﻿CLAYS 
  OF 
  ]^EW 
  YORK 
  821 
  

  

  The 
  following 
  are 
  analyses 
  of 
  Long 
  Island 
  stoneware 
  clays 
  made 
  

   by 
  C. 
  H. 
  Jouet. 
  {School 
  of 
  mines 
  quart. 
  Jan. 
  1895) 
  

  

  Silica 
  68.34 
  

  

  Alumina 
  19.89 
  

  

  Ferrous 
  oxid 
  

  

  Lime 
  

  

  Magnesia 
  

  

  Carbonic 
  acid 
  

  

  Sulfuric 
  acid 
  

  

  Potash 
  

  

  Soda 
  

  

  Combined 
  water 
  

  

  WMte 
  clay 
  

  

  froi^ 
  

   North 
  tort 
  

  

  Black 
  clay 
  

  

  from 
  

   Northport 
  

  

  White 
  clay 
  

   f 
  om 
  

   Seae 
  iff 
  

  

  68.34 
  

  

  58.84 
  

  

  62.35 
  

  

  19.89 
  

  

  23.40 
  

  

  23.14 
  

  

  .90 
  

  

  1.18 
  

  

  1.12 
  

  

  .35 
  

  

  

  

  tr. 
  

  

  

  

  

  1.03 
  

  

  1.09 
  

  

  3.55 
  

  

  5.04 
  

  

  3.17 
  

  

  .84 
  

  

  .34 
  

  

  1.76 
  

  

  6.03 
  

  

  9.20 
  

  

  6.77 
  

  

  99.90 
  

  

  99.03 
  

  

  99.40 
  

  

  A 
  physical 
  test 
  of 
  the 
  yellow 
  clay 
  from 
  the 
  pits 
  of 
  the 
  l!Torthport 
  

   clay 
  and 
  fire 
  sand 
  co. 
  gave 
  the 
  following 
  results. 
  It 
  took 
  25^ 
  of 
  

   water 
  to 
  mix 
  the 
  clay 
  up 
  to 
  a 
  workable 
  mass, 
  that 
  was 
  very 
  gritty, 
  

   but 
  possessed 
  good 
  plasticity. 
  The 
  tensile 
  strength 
  of 
  the 
  clay 
  does 
  

   not 
  stand 
  in 
  direct 
  relation 
  to 
  the 
  plasticity, 
  as 
  the 
  average 
  is 
  only 
  

   25 
  pounds 
  a 
  square 
  inch 
  with 
  a 
  maximum 
  of 
  30 
  pounds. 
  The 
  

   air 
  shrinkage 
  of 
  the 
  bricklet 
  was 
  5^^, 
  and 
  at 
  2300° 
  F. 
  the 
  total 
  

   shrinkage 
  was 
  12^. 
  At 
  this 
  temperature 
  the 
  clay 
  had 
  burned 
  buff, 
  

   and 
  was 
  nearly 
  vitrified. 
  Viscosity 
  occurred 
  in 
  the 
  Deville 
  fur- 
  

   nace 
  at 
  cone 
  27. 
  

  

  The 
  mechanical 
  analysis 
  of 
  the 
  clay 
  shows 
  the 
  high 
  percentage 
  of 
  

   sand 
  contained, 
  which 
  is 
  evidently 
  responsible 
  for 
  its 
  low 
  refractory 
  

   quality. 
  

  

  Clay 
  substance 
  ) 
  oa 
  

  

  Silt 
  ) 
  

  

  Very 
  fine 
  sand 
  60 
  

  

  Fine 
  sand 
  9 
  

  

  99 
  

  

  