﻿274 
  Geologicai, 
  Survey 
  of 
  Louisiana 
  [Sect. 
  

  

  to 
  a 
  very 
  dense 
  hard 
  body, 
  and 
  could 
  perhaps 
  be 
  used 
  for 
  paving 
  

   brick. 
  

  

  The 
  percentage 
  of 
  soluble 
  salts 
  amounted 
  to 
  a 
  mere 
  trace. 
  It 
  

   would 
  work 
  for 
  common 
  earthenware 
  articles 
  of 
  small 
  size, 
  but 
  

   for 
  stoneware 
  it 
  would 
  probably 
  be 
  found 
  more 
  desirable 
  to 
  mix 
  

   it 
  with 
  a 
  more 
  plastic 
  cla5^ 
  

  

  151. 
  (Survey 
  10.) 
  Sec. 
  17, 
  T. 
  3 
  N., 
  R. 
  11 
  W. 
  

  

  This 
  clay 
  is 
  very 
  plastic 
  and 
  while 
  it 
  contains 
  little 
  coarse 
  grit 
  

   it 
  has 
  much 
  very 
  fine 
  sand. 
  It 
  took 
  31 
  per 
  cent 
  of 
  water 
  to 
  

   work 
  it 
  up, 
  and 
  the 
  tensile 
  strength 
  of 
  the 
  air 
  dried 
  briquettes 
  

   was 
  75 
  lbs. 
  per 
  sq. 
  in. 
  

  

  The 
  mechanical 
  anal^^sis 
  gave 
  : 
  

  

  Clay 
  and 
  fine 
  silt 
  42. 
  10 
  per 
  cent 
  

  

  Very 
  fine 
  sand 
  57-25 
  " 
  

  

  99-35 
  

   The 
  air 
  shrinkage 
  was 
  11 
  per 
  cent. 
  

  

  At 
  cone 
  3 
  the 
  clay 
  burned 
  light 
  red 
  and 
  the 
  total 
  shrinkage 
  was 
  

   12 
  per 
  cent. 
  

  

  At 
  cone 
  6 
  the 
  total 
  shrinkage 
  was 
  14 
  per 
  cent 
  and 
  the 
  color 
  of 
  

   the 
  brick 
  brownish 
  red, 
  while 
  incipient 
  fusion 
  had 
  begun. 
  

  

  If 
  burned 
  to 
  this 
  temperature 
  the 
  clay 
  would 
  no 
  doubt 
  make 
  a 
  

   good 
  grade 
  of 
  face 
  brick. 
  It 
  is 
  not 
  a 
  fire 
  clay 
  for 
  at 
  cone 
  26 
  it 
  

   became 
  thoroughly 
  viscous. 
  

  

  The 
  clay 
  contained 
  but 
  one-tenth 
  per 
  cent, 
  of 
  soluble 
  salts. 
  

  

  Ivike 
  the 
  preceding 
  it 
  would 
  do 
  for 
  making 
  earthenware, 
  and 
  

   good 
  pressed 
  brick 
  as 
  well. 
  

  

  152. 
  St. 
  Joe 
  Brick 
  Clay, 
  St. 
  Tamman}^ 
  Parish, 
  La. 
  

  

  A 
  sandy 
  mottled 
  clay 
  that 
  slakes 
  very 
  fast. 
  It 
  took 
  21 
  per 
  

   cent 
  of 
  water 
  to 
  work 
  it 
  up 
  and 
  gave 
  a 
  plastic 
  but 
  slightly 
  gritty 
  

   mass, 
  which 
  for 
  practical 
  purposes 
  does 
  no 
  harm. 
  The 
  tensile 
  

   strength 
  of 
  the 
  air 
  dried 
  briquette 
  was 
  60 
  lbs. 
  per 
  sq. 
  in. 
  

   The 
  mechanical 
  analysis 
  yielded, 
  

  

  Fine 
  sand 
  63.00 
  per 
  cent 
  

  

  Clay 
  and 
  fine 
  silt 
  36.50 
  " 
  

  

  9950 
  

   The 
  air 
  shrinkage 
  was 
  only 
  4 
  per 
  cent 
  which 
  is 
  due 
  to 
  the 
  high 
  

  

  sand 
  percentage 
  shown 
  by 
  the 
  mechanical 
  analysis. 
  

  

  At 
  cone 
  3 
  the 
  clay 
  burns 
  bright 
  brick 
  red 
  and 
  shows 
  specks 
  of 
  

  

  fused 
  pyrite. 
  

  

  