﻿"786 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Analyses 
  of 
  fire 
  hrich 
  used 
  in 
  above 
  tests 
  

  

  Grecian 
  American 
  Silica 
  Coke 
  oven 
  

  

  magnesite 
  magnesite 
  brick 
  tiling 
  

  

  SiO 
  2.16 
  3.10 
  94.07 
  69.89 
  

  

  FeA-hAlA 
  72 
  6.64: 
  3.66 
  27. 
  75 
  

  

  CaO 
  4.20 
  3.76 
  1.39 
  .27 
  

  

  MgO 
  93 
  . 
  03 
  86 
  . 
  50 
  .19 
  .17 
  

  

  Specific 
  

   gravity 
  

  

  Weight 
  a 
  

   cubic 
  foot 
  

  

  

  Founds 
  

  

  3.54 
  

  

  170.2 
  

  

  3.44 
  

  

  160.9 
  

  

  2.56 
  

  

  109.9 
  

  

  2.54 
  

  

  111.4 
  

  

  Tlie 
  specific 
  gravities 
  and 
  weight 
  to 
  tlie 
  cubic 
  foot 
  were: 
  

   Specific 
  gravity 
  of 
  fire 
  brick 
  

  

  Grecian 
  

  

  American 
  . 
  . 
  . 
  . 
  , 
  

   Coke 
  oven 
  tiling 
  

   Silica 
  brick 
  . 
  . 
  . 
  , 
  

  

  Glass 
  pot 
  clays 
  

  

  Glass 
  pots 
  are 
  made 
  of 
  a 
  special 
  grade 
  of 
  refractory 
  clay, 
  whose 
  

   necessary 
  qualities 
  are 
  given 
  below. 
  While 
  no 
  glass 
  pot 
  clays 
  are 
  

   found 
  in 
  this 
  state, 
  still 
  many 
  of 
  the 
  glass 
  factories 
  in 
  ISTew 
  York 
  

   obtain 
  the 
  raw 
  clays 
  elsewhere 
  and 
  make 
  the 
  pots 
  at 
  their 
  works. 
  

   Great 
  care 
  has 
  to 
  be 
  exercised 
  in 
  their 
  manufacture; 
  not 
  only 
  must 
  

   the 
  clay 
  be 
  thoroughly 
  weathered, 
  but 
  the 
  molded 
  pot 
  must 
  be 
  

   free 
  from 
  the 
  slightest 
  cracks 
  and 
  exhibit 
  a 
  homogeneous 
  structure 
  

   throughout. 
  

  

  Requisite 
  characters. 
  A 
  clay, 
  in 
  order 
  to 
  be 
  suitable 
  for 
  the 
  

   manufacture 
  of 
  glass 
  pots 
  or 
  blocks 
  for 
  tank 
  furnaces 
  should 
  con- 
  

   form 
  to 
  the 
  following 
  requirements: 
  

  

  1 
  Sufficient 
  refractoriness 
  to 
  withstand 
  the 
  highest 
  heat 
  used 
  

   without 
  changing 
  form 
  

  

  2 
  Great 
  plasticity, 
  such 
  that 
  the 
  addition 
  of 
  50';^-60;i^ 
  of 
  grog 
  

   will 
  not 
  affect 
  it 
  appreciably 
  

  

  3 
  In 
  burning, 
  density 
  at 
  as 
  low 
  a 
  temperature 
  as 
  possible 
  

  

  A 
  clay 
  is 
  generally 
  considered 
  sufficiently 
  refractory 
  for 
  making 
  

   glass 
  pots 
  if 
  its 
  fusion 
  point 
  is 
  the 
  same 
  as 
  that 
  of 
  cone 
  30. 
  It 
  

  

  