﻿720 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  buff 
  buniiiig 
  or 
  lower 
  clay 
  is 
  distinctly 
  marly 
  in 
  its 
  char- 
  

   acter. 
  As 
  might 
  be 
  expected, 
  it 
  takes 
  only 
  18.50^ 
  water 
  to 
  work 
  

   it 
  up, 
  but 
  still 
  is 
  quite 
  plastic. 
  The 
  air 
  shrinkage 
  is 
  6^, 
  and 
  at 
  

   cone 
  .08, 
  5^. 
  The 
  clay 
  vitrifies 
  at 
  cone 
  1 
  with 
  14^ 
  shrinkage, 
  and 
  

   becomes 
  viscous 
  nearly 
  at 
  cone 
  2. 
  It 
  burns 
  buff, 
  but 
  with 
  viscosity 
  

   this 
  passes 
  into 
  greenish 
  yellow. 
  The 
  tensile 
  strength 
  ranges 
  from 
  

   95 
  to 
  110 
  pounds 
  a 
  square 
  inch. 
  The 
  clay 
  contains 
  .7^ 
  soluble 
  

   salts. 
  

  

  Rochester, 
  Monroe 
  co. 
  The 
  Rochester 
  brick 
  and 
  tile 
  manufac- 
  

   turing 
  CO. 
  is 
  on 
  Monroe 
  street, 
  at 
  the 
  eastern 
  end 
  of 
  the 
  city. 
  Ad- 
  

   joining 
  this 
  is 
  the 
  German 
  brick 
  and 
  tile 
  co. 
  The 
  clay 
  is 
  reddish 
  

   in 
  color, 
  4 
  to 
  5 
  feet 
  thick 
  and 
  underlain 
  by 
  hardpan. 
  Lime 
  pebbles 
  

   occur 
  in 
  the 
  lower 
  portions. 
  Molding 
  sand 
  is 
  obtained 
  from 
  a 
  neigh- 
  

   boring 
  eskar. 
  

  

  The 
  following 
  is 
  an 
  analysis 
  of 
  this 
  clay. 
  

  

  Silica 
  50.65 
  

  

  Alumina 
  15 
  . 
  46 
  

  

  Peroxid 
  of 
  iron 
  4.38 
  

  

  Lime 
  10.95 
  

  

  Magnesia 
  3.35 
  

  

  Alkalis 
  6 
  . 
  30 
  

  

  90.99 
  

  

  The 
  whole 
  flat 
  area 
  to 
  the 
  west 
  and 
  northwest 
  of 
  the 
  yards 
  was 
  

   formerly 
  underlain 
  by 
  clay, 
  but 
  so 
  much 
  of 
  it 
  has 
  been 
  dug 
  over 
  

   that 
  the 
  pit 
  is 
  now 
  nearly 
  a 
  quarter 
  of 
  a 
  mile 
  fro^m 
  the 
  works. 
  The 
  

   section 
  in 
  the 
  present 
  clay 
  pit 
  involves 
  : 
  

  

  Loam 
  18 
  inches 
  

  

  Sandy 
  clay 
  2 
  feet 
  

  

  Fat 
  clay 
  4 
  feet 
  

  

  Hardpan 
  

  

  