﻿800 
  

  

  ^'EW 
  YORK 
  STATE 
  MUSEUM 
  

  

  tains 
  an 
  axis 
  with 
  iron 
  arms, 
  tlieir 
  revolution 
  serving 
  to 
  break 
  up 
  

   the 
  claj, 
  which 
  is 
  charged 
  through 
  a 
  hopper 
  at 
  the 
  top. 
  A 
  cur- 
  

   rent 
  of 
  water 
  passes 
  through 
  the 
  cylinder 
  and 
  carries 
  the 
  fine 
  clay 
  

   particles 
  with 
  it, 
  while 
  the 
  coarse 
  ones 
  are 
  left 
  behind 
  in 
  the 
  

   machine. 
  The 
  speed 
  of 
  the 
  current 
  has 
  to 
  be 
  regulated 
  by 
  experi- 
  

   ment, 
  for 
  if 
  too 
  much 
  water 
  is 
  used 
  coarse 
  material 
  will 
  be 
  washed 
  

   out 
  of 
  the 
  cylinder, 
  and 
  conversely 
  if 
  the 
  current 
  is 
  too 
  slow 
  the 
  

   clay 
  will 
  not 
  yield 
  a 
  sufficient 
  percentage 
  of 
  washed 
  product. 
  One 
  

   objection 
  to 
  this 
  apparatus 
  is 
  that 
  it 
  has 
  to 
  be 
  stopped 
  from 
  time 
  

   to 
  time 
  to 
  remove 
  the 
  coarse 
  sand 
  from 
  the 
  machine. 
  

  

  The 
  method 
  most 
  commonly 
  used 
  at 
  the 
  present 
  day 
  for 
  washing 
  

   kaolin 
  is 
  in 
  its 
  general 
  detail 
  as 
  follows: 
  

  

  As 
  the 
  kaolin 
  comes 
  from 
  the 
  mine 
  it 
  is 
  generally 
  discharged 
  

   into 
  a 
  log 
  washer, 
  a 
  semicylindric 
  trough, 
  in 
  which 
  revolves 
  a 
  

   horizontal 
  axis, 
  bearing 
  short 
  arms. 
  The 
  action 
  of 
  the 
  arms 
  breaks 
  

   up 
  the 
  kaolin 
  more 
  or 
  less 
  thorouglily, 
  according 
  to 
  its 
  density, 
  

   and 
  facilitates 
  the 
  subsequent 
  washing. 
  The 
  stream 
  of 
  water 
  

   directed 
  into 
  the 
  log 
  washer, 
  sweeps 
  the 
  kaolin 
  and 
  most 
  of 
  the 
  

   sand 
  into 
  the 
  washing 
  trough, 
  which 
  is 
  about 
  15 
  inches 
  wide 
  and 
  

   12 
  inches 
  deep, 
  but 
  should 
  be 
  wider 
  and 
  deeper 
  if 
  the 
  kaolin 
  is 
  

   very 
  sandy. 
  The 
  troughing 
  is 
  about 
  700 
  feet 
  long, 
  and 
  to 
  utilize 
  

   the 
  space 
  thoroughly 
  it 
  is 
  broken 
  up 
  into 
  sections 
  (50 
  feet 
  each 
  

   is 
  a 
  good 
  length) 
  these 
  being 
  arranged 
  parallel, 
  and 
  connecting 
  at 
  

   the 
  ends, 
  so 
  that 
  the 
  water, 
  with 
  suspended 
  clay, 
  follows 
  a 
  zigzag 
  

   course. 
  

  

  The 
  troughing 
  has 
  a 
  sKght 
  pitch, 
  commonly 
  about 
  one 
  inch 
  

   in 
  20 
  feet, 
  but 
  the 
  amount 
  depends 
  on 
  the 
  kaolin, 
  and 
  whether 
  th6 
  

   contained 
  sand 
  is 
  fine 
  or 
  coarse. 
  If 
  the 
  kaolin 
  is 
  very 
  fine, 
  and 
  

   settles 
  slowly, 
  the 
  pitch 
  need 
  not 
  be 
  so 
  gTeat, 
  and. 
  ^4ce 
  versa. 
  A 
  

   large 
  quantity 
  of 
  very 
  coarse 
  sand 
  in 
  the 
  kaolin 
  is 
  a 
  nuisance, 
  as 
  

   it 
  clogs 
  up 
  the 
  log 
  washer 
  and 
  the 
  upper 
  end 
  of 
  the 
  trough 
  more 
  

   quickly, 
  causing 
  much 
  labor 
  to 
  keep 
  them 
  clean. 
  As 
  it 
  is, 
  con- 
  

   siderable 
  sand 
  settles 
  there, 
  and, 
  to 
  keep 
  the 
  trough 
  clear, 
  sand 
  

   wheels 
  are 
  used. 
  The 
  wheels 
  are 
  wooden, 
  bearing 
  a 
  number 
  of 
  

  

  