﻿CLAYS 
  OF 
  IsEW 
  YORK 
  773 
  

  

  HOLLOW 
  BRICK, 
  TERRA 
  COTTA 
  LUMBER, 
  FIRE- 
  

  

  PROOrmG. 
  

  

  The 
  first 
  term 
  is 
  generally 
  applied 
  to 
  large 
  hollow 
  bricks 
  of 
  

   more 
  or 
  less 
  rectangular 
  shape, 
  having 
  cross 
  partitions. 
  They 
  are 
  

   made 
  either 
  of 
  brick 
  clay 
  or 
  semi-fire 
  clay, 
  the 
  latter 
  being 
  the 
  

   better 
  if 
  protection 
  against 
  fire 
  is 
  desired. 
  The 
  term 
  terra 
  cotta 
  

   lumber 
  is 
  specially 
  applied 
  to 
  bricks 
  of 
  this 
  class 
  made 
  of 
  a 
  mix- 
  

   ture 
  of 
  clay 
  and 
  sawdust, 
  so 
  that 
  in 
  burning 
  the 
  sawdust 
  burns 
  

   out, 
  leaving 
  the 
  body 
  of 
  the 
  ware 
  porous. 
  

  

  The 
  shape 
  of 
  these 
  bricks 
  is 
  quite 
  variable, 
  and 
  can 
  best 
  be 
  

   judged 
  by 
  reference 
  to 
  plate 
  103. 
  They 
  are 
  used 
  for 
  the 
  construc- 
  

   tion 
  of 
  floor 
  arches, 
  partitions, 
  flue 
  linings, 
  and 
  for 
  wrapping 
  

   around 
  steel 
  beams 
  and 
  girders. 
  They 
  are 
  also 
  used 
  at 
  times 
  as 
  

   foundation 
  blocks 
  in 
  buildings, 
  in 
  which 
  case, 
  the 
  brick 
  are 
  salt 
  

   glazed 
  to 
  prevent 
  absorption, 
  if 
  the 
  body 
  of 
  it 
  is 
  not 
  vitrified. 
  

   One 
  of 
  the 
  purposes 
  of 
  these 
  bricks 
  is 
  to 
  combine 
  lightness 
  and 
  

   strength, 
  in 
  addition 
  the 
  hollow 
  spaces 
  serve 
  as 
  nonconductors 
  

   of 
  heat. 
  

  

  "When 
  used 
  for 
  fireproofing 
  purposes, 
  the 
  product 
  should 
  be 
  

   such 
  that 
  it 
  will 
  resist 
  any 
  heat 
  to 
  which 
  it 
  might 
  be 
  exposed 
  in 
  

   case 
  of 
  fire, 
  and 
  when 
  heated 
  it 
  should 
  be 
  able 
  to 
  withstand 
  a 
  

   stream 
  of 
  cold 
  water 
  without 
  splitting 
  off 
  or 
  cracking. 
  It 
  is 
  for 
  

   the 
  latter 
  reason 
  that 
  hollow 
  bricks 
  used 
  for 
  fireproofing 
  should 
  

   be 
  made 
  from 
  a 
  semi-fire 
  clay, 
  and 
  should 
  not 
  be 
  vitrified. 
  

  

  Hollow 
  brick 
  are 
  manufactured 
  at 
  a 
  number 
  of 
  places 
  in 
  ISTew 
  

   York 
  state 
  ; 
  the 
  material 
  used 
  is 
  in 
  some 
  cases 
  shale, 
  in 
  other 
  cases 
  

   clay. 
  They 
  are 
  molded 
  in 
  the 
  same 
  kind 
  of 
  press 
  as 
  sewer 
  pipe. 
  

   Reference 
  to 
  plate 
  102 
  will 
  show 
  the 
  style 
  of 
  die 
  employed. 
  

  

  