﻿790 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  mecitamcal 
  analysis 
  is: 
  

  

  Clay 
  substance 
  92 
  . 
  50 
  

  

  Snt 
  2.30 
  

  

  Yery 
  fine 
  sand 
  .80 
  

  

  Fine 
  sand 
  4 
  . 
  60 
  

  

  100.20 
  

  

  A 
  sample 
  of 
  tlie 
  better 
  grade 
  fire 
  clary 
  from 
  tlie 
  present 
  large 
  

   opening 
  was 
  likewise 
  tested, 
  as 
  it 
  represents 
  a 
  common 
  type 
  of 
  clay 
  

   found 
  on 
  Staten 
  Island. 
  

  

  This 
  was 
  far 
  more 
  plastic 
  than 
  the 
  other 
  two; 
  it 
  had 
  a 
  tensile 
  

   strength 
  of 
  45 
  pounds 
  a 
  square 
  inch. 
  30^ 
  of 
  water 
  gave 
  a 
  workable 
  

   mass, 
  whose 
  air 
  shrinkage 
  was 
  8.25^. 
  "When 
  burned 
  to 
  cone 
  12 
  

   the 
  color 
  was 
  yellowish 
  white 
  and 
  the 
  total 
  shrinkage 
  17^. 
  

  

  The 
  clay 
  did 
  not 
  fuse 
  at 
  cone 
  30 
  in 
  the 
  Deville 
  furnace; 
  so 
  that 
  

   it 
  can 
  be 
  properly 
  classed 
  as 
  a 
  fire 
  clay. 
  

  

  The 
  mechanical 
  analysis 
  gave 
  : 
  

  

  Clay 
  substance 
  70 
  

  

  Silt 
  7 
  

  

  Yery 
  fine 
  sa.nd 
  7 
  

  

  Tine 
  sand 
  14 
  

  

  98 
  

  

  