﻿564 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  CLASSIFICATION 
  

  

  As 
  clajs 
  show 
  all 
  gradations 
  from 
  the 
  purest 
  kaolins 
  to 
  the 
  most 
  

   impure 
  brick 
  clays, 
  it 
  is 
  hard 
  to 
  draw 
  any 
  sharp 
  lines 
  of 
  division 
  

   between 
  the 
  different 
  kinds. 
  These 
  great 
  divisions 
  can 
  however 
  

   be 
  made, 
  residual 
  and 
  sedimentary, 
  and 
  to 
  these 
  might 
  be 
  added 
  

   a 
  third, 
  chemical 
  precipitates. 
  

  

  Each 
  of 
  these 
  three 
  may 
  include 
  varieties 
  having 
  similar 
  prop- 
  

   erties 
  and 
  similar 
  uses. 
  

  

  Soger 
  makes 
  the 
  following 
  divisions: 
  

  

  1 
  Yellow 
  burning 
  y 
  containing 
  lime 
  and 
  iron 
  

  

  2 
  Red 
  hurning, 
  nonalumuious, 
  ferruginous 
  clays 
  which 
  are 
  free 
  

   from 
  lime 
  

  

  3 
  White 
  and 
  yellow 
  turning, 
  clays 
  low 
  in 
  both 
  iron 
  and 
  lime 
  

  

  4 
  White 
  hurning, 
  low 
  in 
  iron 
  and 
  high 
  in 
  alumina 
  

  

  To 
  give 
  a 
  classification 
  based 
  on 
  the 
  uses 
  of 
  the 
  clay 
  is 
  also 
  unsatr 
  

   isfactory, 
  for 
  some 
  clays 
  may 
  be 
  used 
  for 
  as 
  much 
  as 
  five 
  or 
  six 
  

   different 
  purposes, 
  either 
  alone 
  or 
  mixed 
  with 
  other 
  clays. 
  

  

  A 
  rough 
  classification 
  based 
  on 
  their 
  use 
  would 
  be 
  perhaps 
  some- 
  

   what 
  as 
  follows: 
  

  

  Brick 
  clays 
  

  

  Potter's 
  clays 
  

  

  China 
  clays 
  

  

  Fire 
  clays 
  " 
  s 
  

  

  A 
  good 
  idea 
  of 
  the 
  varied 
  uses 
  of 
  clays 
  may 
  be 
  obtained 
  from 
  the 
  

   following 
  table 
  compiled 
  by 
  E. 
  T. 
  HilP 
  and 
  added 
  to 
  by 
  the 
  writer. 
  

  

  Uses 
  

  

  1 
  Domestic. 
  Utensils, 
  porcelain 
  ware; 
  china 
  ware; 
  granite 
  or 
  

   iron-stone 
  ware; 
  yellow 
  ware; 
  rockingham 
  ware; 
  earthenware; 
  ma- 
  

   jolica; 
  stoves; 
  polishing 
  brick. 
  

  

  2 
  Structural. 
  Brick, 
  common, 
  front, 
  pressed, 
  ornamental, 
  hol- 
  

   low, 
  glazed; 
  adobe; 
  terra 
  cotta; 
  roofing 
  tile; 
  glazed 
  and 
  encaustic 
  

  

  1 
  U. 
  S. 
  Geol. 
  surv., 
  Min. 
  res. 
  of 
  U. 
  8. 
  1891. 
  p. 
  475. 
  

  

  