﻿Ill] 
  

  

  Special 
  Report 
  No. 
  4 
  : 
  Clays 
  

  

  271 
  

  

  that 
  .07 
  is 
  bent 
  over 
  in 
  burning 
  but 
  5 
  is 
  not 
  affected. 
  Then 
  the 
  

   temperature 
  of 
  the 
  kiln 
  was 
  between 
  3 
  and 
  5. 
  The 
  next 
  time 
  

   2, 
  3 
  and 
  4 
  are 
  put 
  in, 
  and 
  2 
  and 
  3 
  may 
  be 
  fused 
  but 
  4 
  remain 
  

   unaffected, 
  indicating 
  that 
  the 
  temperature 
  reached 
  the 
  fusing 
  

   point 
  of 
  three. 
  If 
  this 
  is 
  the 
  temperature 
  at 
  which 
  the 
  burning 
  

   of 
  the 
  kiln 
  is 
  completed 
  then 
  in 
  future 
  burnings 
  it 
  is 
  only 
  neces- 
  

   sary 
  to 
  put 
  cone 
  three 
  in 
  the 
  kiln 
  and 
  raise 
  the 
  • 
  fire 
  until 
  this 
  

   bends 
  over. 
  These 
  cones 
  can 
  be 
  obtained 
  for 
  the 
  sum 
  of 
  one 
  cent 
  

   each 
  from 
  Prof. 
  E. 
  Orton, 
  Jr., 
  of 
  Columbus, 
  O. 
  In 
  the 
  testing 
  

   of 
  the 
  samples 
  of 
  the 
  Louisiana 
  clays 
  these 
  cones 
  were 
  used, 
  and 
  

   the 
  fusibility 
  of 
  the 
  clay 
  is 
  expressed 
  in 
  terms 
  of 
  them. 
  For 
  the 
  

   temperature 
  of 
  the 
  fusing 
  points 
  of 
  these 
  cones 
  reference 
  can 
  be 
  

   made 
  to 
  the 
  following 
  list 
  which 
  gives 
  the 
  fusion 
  points 
  in 
  

   degrees 
  Fahrenheit. 
  

  

  Slaking. 
  — 
  When 
  a 
  lump, 
  or 
  mass 
  of 
  clay 
  is 
  thrown 
  into 
  water 
  

   it 
  falls 
  to 
  pieces. 
  This 
  is 
  called 
  slaking. 
  Some 
  clays 
  slake 
  very 
  

   rapidly, 
  while 
  in 
  the 
  case 
  of 
  others 
  it 
  proceeds 
  so 
  slowly 
  aS 
  to 
  be 
  

   almost 
  imperceptible. 
  Sandy 
  clays 
  tend 
  to 
  slake 
  more 
  rapidly, 
  

   than 
  fine 
  grained 
  or 
  dense 
  ones, 
  and 
  shales 
  will 
  at 
  times 
  not 
  

   slake 
  at 
  all, 
  although 
  on 
  grinding 
  and 
  mixing 
  with 
  water 
  they 
  

  

  