﻿688 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  These 
  clays 
  are 
  sticky 
  wlien 
  mixed 
  with 
  water, 
  but 
  they 
  are 
  by 
  

   no 
  means 
  to 
  be 
  called 
  highly 
  plastic 
  ; 
  indeed, 
  when 
  worked 
  up 
  with 
  

   water 
  the 
  mass 
  shows 
  a 
  certain 
  resistance 
  to 
  mobility 
  that 
  is 
  hard 
  

   to 
  describe, 
  but 
  is 
  not 
  unlike 
  a 
  mass 
  of 
  powdered 
  feldspar 
  in 
  its 
  

   behavior. 
  

  

  When 
  thrown 
  into 
  water 
  the 
  clay 
  slakes 
  quite 
  readily 
  to 
  a 
  

   flocculent 
  mass. 
  

  

  Two 
  samples 
  were 
  tested 
  physically, 
  the 
  one 
  from 
  Rose's 
  yard 
  

   at 
  Roseton 
  above 
  Newburgh, 
  and 
  the 
  other 
  from 
  the 
  Brockway 
  

   brick 
  co.'s 
  yard 
  above 
  Fishkill. 
  

  

  The 
  sample 
  from 
  the 
  bank 
  of 
  the 
  Brockway 
  brick 
  co. 
  (109) 
  

   worked 
  up 
  to 
  a 
  sticky, 
  but 
  not 
  highly 
  plastic 
  mass 
  with 
  29^ 
  of 
  water. 
  

   The 
  bricklets 
  showed 
  an 
  air 
  shrinkage 
  of 
  5^-6^. 
  

  

  The 
  tensile 
  strength 
  of 
  air-dried 
  briquettes 
  was 
  75 
  to 
  90 
  pounds 
  

   a 
  square 
  inch, 
  but 
  some 
  reached 
  120 
  pounds 
  a 
  square 
  inch. 
  

  

  The 
  clay 
  also 
  gave 
  .2^ 
  of 
  soluble 
  salts. 
  

  

  In 
  burning, 
  the 
  clay 
  burned 
  red 
  with 
  increasing 
  depth 
  of 
  color 
  

   as 
  the 
  temperature 
  was 
  raised 
  and 
  at 
  viscosity 
  passed 
  to 
  a 
  brownish 
  

   glass. 
  Incipient 
  fusion 
  occurred 
  at 
  cone 
  .05 
  with 
  a 
  total 
  shrinkage 
  

   of 
  8^. 
  Vitrification 
  at 
  cone 
  .04 
  with 
  a 
  shrinkage 
  of 
  15^. 
  Viscosity 
  

   took 
  place 
  at 
  cone 
  .01. 
  

  

  The 
  clay 
  from 
  Roseton 
  was 
  very 
  similar 
  in 
  its 
  behavior 
  to 
  the 
  

   previous 
  one. 
  

  

  The 
  air 
  shrinkage 
  was 
  5^. 
  Incipient 
  fusion 
  occurred 
  at 
  cone 
  .05^ 
  

   vitrification 
  at 
  cone 
  .04 
  with 
  a 
  total 
  shrinkage 
  of 
  14^. 
  At 
  .01 
  the 
  

   clay 
  became 
  viscous. 
  The 
  tensile 
  strength 
  ranged 
  from 
  75 
  to 
  93 
  

   pounds 
  a 
  square 
  inch. 
  

  

  The 
  soluble 
  salts 
  amounted 
  to 
  .3^. 
  

  

  A 
  mechanical 
  analysis 
  of 
  the 
  clay 
  from 
  the 
  bank 
  of 
  the 
  Brock- 
  

   way 
  brick 
  CO. 
  yielded 
  , 
  

  

  Clay 
  substance 
  49 
  . 
  83^ 
  

  

  Silt 
  and 
  very 
  fine 
  sand 
  28 
  . 
  30;^ 
  

  

  Fine 
  sand 
  21.75;^ 
  

  

  