﻿CLAYS 
  OF 
  Is^EW 
  YOKK 
  565 
  

  

  tile; 
  drain 
  tile; 
  chimney 
  fines; 
  chimney 
  pots; 
  door 
  knobs; 
  puddling; 
  

   Portland 
  cement; 
  fireproofing; 
  terra 
  cotta 
  lumber; 
  pa^dng 
  brick 
  

   copings 
  

  

  3 
  Agricultural. 
  Drain 
  tile, 
  bam 
  flooring 
  

  

  4 
  Hydraulic 
  structureB. 
  Water 
  conduits; 
  sewer 
  pipe; 
  sewer 
  

   brick; 
  turbine 
  wheels 
  

  

  5 
  Sanitary 
  engineering. 
  Granite 
  ware 
  ; 
  urinals 
  and 
  closet 
  bowls 
  ; 
  

   wash 
  tubs; 
  bath 
  tubs; 
  sewer 
  pipe; 
  ventilating 
  flues; 
  foundatioai 
  

   blocks; 
  vitrified 
  brick 
  

  

  6 
  Industrial 
  uses. 
  Crucibles 
  and 
  other 
  assaying 
  apparatus, 
  acid 
  

   vats 
  and 
  jars; 
  acid 
  bricks, 
  gas 
  retorts; 
  fire 
  bricks; 
  glass 
  pots; 
  sag- 
  

   gers; 
  stove 
  and 
  furnace 
  linings; 
  wall 
  and 
  writing 
  paper 
  fillings; 
  

   porcelain 
  chemical 
  apparatus; 
  grinding 
  mills; 
  insulators; 
  pumps; 
  

   filters; 
  mineral 
  paint; 
  packing 
  horses 
  hoofs; 
  fulling 
  cloth; 
  ultra- 
  

   marine 
  manufacture 
  

  

  7 
  Ornamental 
  and 
  esthetic 
  uses. 
  All 
  forms 
  of 
  ornamental 
  pot- 
  

   tery; 
  terra 
  cotta 
  and 
  various 
  forms 
  of 
  tiles 
  either 
  glazed 
  or 
  unglazed 
  

  

  8 
  Imitative 
  uses. 
  Food 
  adulterants 
  and 
  paint 
  adulterants 
  

  

  Ccloring 
  agents 
  

   This 
  includes 
  those 
  substances 
  which 
  impart 
  a 
  definite 
  color 
  to 
  

   the 
  clay 
  in 
  burning. 
  Pure 
  clay 
  would 
  bum 
  to 
  a 
  snow 
  white 
  color, 
  

   but 
  in 
  nature 
  it 
  is 
  frequently 
  tinged 
  with 
  more 
  or 
  less 
  impurity. 
  

   The 
  most 
  common 
  coloring 
  agent 
  is 
  oxid 
  of 
  iron 
  or 
  iron 
  compounds 
  

   which, 
  in 
  burning, 
  change 
  to 
  the 
  oxid. 
  The 
  depth 
  of 
  color 
  pro- 
  

   duced 
  in 
  burning 
  depends 
  on 
  the 
  amount 
  of 
  iron 
  present. 
  It 
  may 
  

   vary 
  froni 
  the 
  lightest 
  yellow 
  to 
  red 
  and 
  dark 
  brown 
  or 
  bluish 
  

   black. 
  The 
  presence 
  of 
  other 
  compounds 
  may 
  however 
  have 
  a 
  

   marked 
  influence 
  on 
  the 
  iron 
  coloration. 
  Some 
  of 
  the 
  purest 
  clays 
  

   known, 
  though 
  containing 
  a 
  mere 
  fraction 
  of 
  a 
  per 
  cent 
  of 
  iron 
  

   oxid, 
  will, 
  nevertheless, 
  when 
  burned 
  at 
  a 
  very 
  high 
  temperature, 
  

   develop 
  a 
  very 
  slightly 
  yellow 
  tint. 
  If 
  such 
  clays 
  have 
  a 
  con- 
  

   siderable 
  amount 
  of 
  feldspar 
  added 
  to 
  them, 
  they 
  keep 
  this 
  yellow 
  

   color; 
  on 
  the 
  other 
  hand 
  the 
  addition 
  of 
  quartz 
  tends 
  to 
  minimize 
  

   it. 
  Magnesia 
  and 
  lime 
  may 
  exert 
  a 
  much 
  stronger 
  effect 
  on 
  the 
  

  

  