﻿832 
  JNEW 
  YOEK 
  STATE 
  MUSEUM 
  

  

  Along 
  the 
  banks 
  of 
  Seneca 
  and 
  Cayuga 
  lakes 
  the 
  full 
  section 
  of 
  

   the 
  Hamilton 
  gTOup 
  may 
  be 
  seen. 
  The 
  lower 
  members 
  are 
  th© 
  

   most 
  northern, 
  and 
  dip 
  to 
  the 
  south 
  under 
  the 
  higher 
  ones. 
  Prof. 
  

   Hall 
  makes 
  the 
  following 
  divisions: 
  

  

  1 
  Dark, 
  slaty 
  fossiliferous 
  shale, 
  resting 
  on 
  the 
  Marcellus 
  shale 
  

  

  2 
  A 
  compact, 
  calcareous 
  blue 
  shale, 
  of 
  little 
  thickness 
  

  

  3 
  An 
  olive 
  or 
  blue 
  shale, 
  which 
  in 
  its 
  upper 
  layers 
  is 
  stained 
  by 
  

   oxid 
  of 
  manganese. 
  This 
  is 
  one 
  of 
  the 
  best 
  adapted 
  for 
  clay 
  

   products 
  

  

  4 
  ' 
  Ludlowville 
  shales, 
  often 
  sandy 
  in 
  their 
  nature 
  

  

  6 
  A 
  limestone 
  

  

  6 
  Moscow 
  shales, 
  of 
  grayish 
  blue 
  color, 
  and 
  slightly 
  calcareous 
  in 
  

   places 
  

  

  These 
  subdivisions 
  can 
  all 
  be 
  seen 
  along 
  the 
  eastern 
  shore 
  of 
  

   Cayuga 
  lake 
  from 
  Springport 
  to 
  Ludlowville. 
  

  

  Cairo, 
  Green 
  co. 
  This 
  is 
  one 
  of 
  two 
  localities 
  at 
  which 
  the 
  Ham- 
  

   ilton 
  shale 
  is 
  mined. 
  The 
  material, 
  which 
  is 
  shipped 
  to 
  the 
  works 
  of 
  

   the 
  Catskill 
  shale 
  paving 
  brick 
  co., 
  at 
  Catskill, 
  is 
  a 
  reddish 
  gritty 
  

   shale 
  possessing 
  little 
  plasticity. 
  This 
  material 
  was 
  at 
  first 
  used 
  

   alone, 
  but 
  found 
  difficult 
  to 
  work 
  on 
  account 
  of 
  its 
  excessive 
  lean- 
  

   ness, 
  and 
  consequently 
  is 
  now 
  mixed 
  with 
  50^ 
  of 
  common 
  red 
  clay 
  

   also 
  obtained 
  from 
  Cairo. 
  Samples 
  of 
  this 
  mixture 
  were 
  tested 
  with 
  

   the 
  following 
  results. 
  The 
  moderately 
  plastic 
  paste 
  shrunk 
  4^ 
  

   in 
  drying, 
  and 
  9^ 
  in 
  burning. 
  Air-dried 
  briquettes 
  had 
  an 
  average 
  

   tensile 
  strength 
  of 
  97 
  pounds 
  a 
  square 
  inch, 
  and 
  a 
  maximum 
  of 
  100 
  

   pounds 
  a 
  square 
  inch. 
  

  

  Incipient 
  fusion 
  occurred 
  at 
  cone 
  .05, 
  vitrification 
  at 
  cone 
  .01^ 
  

   and 
  viscosity 
  at 
  cone 
  2. 
  

  

  The 
  mixture 
  of 
  clay 
  and 
  shale 
  is 
  ground 
  in 
  dry 
  pans, 
  then 
  passes 
  

   to 
  the 
  pug 
  mill 
  on 
  the 
  floor 
  above, 
  whence, 
  after 
  tempering, 
  it 
  is 
  

   discharged 
  to 
  the 
  auger 
  side-cut 
  machine. 
  The 
  bricks 
  are 
  re- 
  

   pressed, 
  dried 
  in 
  tunnels, 
  . 
  and 
  burned 
  in 
  down-draft 
  kilns. 
  The 
  

   company 
  has 
  recently 
  erected 
  a 
  large 
  continuous 
  kiln; 
  in 
  this 
  kiln, 
  

   most 
  of 
  the 
  firing 
  is 
  done 
  in 
  temporary 
  fireplaces 
  built 
  in 
  the 
  door- 
  

  

  