﻿584 
  Fort 
  i- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  copper 
  in 
  the 
  air 
  and 
  cooling, 
  the 
  color 
  was 
  changed 
  to 
  a 
  dull 
  

   red. 
  The 
  color 
  of 
  the 
  stone 
  is 
  thus 
  due 
  partly 
  to 
  ferrous 
  oxide 
  

   of 
  iron 
  and 
  partly 
  to 
  organic 
  matter. 
  The 
  complete 
  series 
  of 
  

   tests 
  made 
  by 
  Prof. 
  Wilbur 
  gave 
  the 
  following 
  results 
  : 
  " 
  Specific 
  

   gravity, 
  2.751 
  ; 
  weight 
  per 
  cubic 
  foot, 
  171 
  pounds, 
  ferrous 
  oxide, 
  

   4.63 
  per 
  cent 
  ; 
  ferric 
  oxide, 
  0.79 
  per 
  cent 
  ; 
  water 
  absorbed, 
  <».82 
  

   per 
  cent 
  ; 
  loss 
  in 
  dilute 
  sulphuric 
  aci<), 
  0.20 
  per 
  cent 
  ; 
  alternate 
  

   freezing 
  and 
  thawing 
  unchanged; 
  at 
  a 
  temperature 
  of 
  1200°- 
  

   1400° 
  F., 
  color 
  changed 
  to 
  a 
  dull 
  red, 
  slightly 
  checked 
  and 
  

   strength 
  somewhat 
  impaired."* 
  

  

  The 
  prevailing 
  color 
  of 
  the 
  stone 
  is 
  a 
  dark 
  or 
  bluish 
  gray. 
  

   There 
  is 
  some 
  reddish 
  colored 
  stone, 
  and 
  even 
  stone 
  of 
  a 
  

   greenish 
  color 
  is 
  found. 
  The 
  preference, 
  however, 
  is 
  for 
  the 
  

   typical 
  blue 
  stone. 
  The 
  typical 
  blue 
  stone 
  is 
  probably 
  that 
  

   which 
  comes 
  from 
  the 
  Hamilton 
  group, 
  while 
  the 
  reddish 
  or 
  

   greenish-colored 
  stone 
  comes 
  from 
  the 
  Catskill 
  series. 
  In 
  texture 
  

   the 
  stone 
  varies 
  from 
  the 
  exceedingly 
  fine-grained 
  material 
  

   which 
  takes 
  a 
  very 
  even 
  finish, 
  to 
  a 
  sandstone 
  which 
  is 
  almost 
  

   conglomeratic 
  in 
  its 
  nature. 
  As 
  may 
  be 
  inferred 
  tLe 
  finer- 
  

   grained 
  material 
  is 
  much 
  stronger. 
  

  

  There 
  is 
  but 
  a 
  small 
  admixture 
  of 
  argillaceous 
  or 
  clayey 
  

   matter 
  and 
  the 
  cementing 
  material 
  is 
  almost 
  wholly 
  silica. 
  This 
  

   insures 
  the 
  durability 
  of 
  the 
  stone, 
  since 
  silica 
  is 
  practically 
  

   unaffected 
  by 
  the 
  exposures 
  which 
  ultimately 
  tell 
  on 
  lime- 
  

   stones, 
  marbles, 
  granites 
  and 
  on 
  calcareous 
  and 
  ferruginous 
  

   sandstones. 
  

  

  The 
  stone 
  is 
  so 
  compact 
  as 
  to 
  absorb 
  but 
  little 
  moisture, 
  and 
  

   thus 
  when 
  used 
  as 
  flagging 
  rain 
  or 
  ice 
  remains 
  upon 
  it 
  but 
  a 
  short 
  

   time. 
  Its 
  hardness 
  re>ists 
  wear 
  and 
  it 
  always 
  wears 
  slightly 
  rough, 
  

   never 
  forming 
  the 
  slippery 
  surfaces 
  of 
  clay 
  slate. 
  The 
  demand 
  

   for 
  the 
  stone 
  seems 
  to 
  be 
  continually 
  increasing. 
  

  

  In 
  view 
  of 
  this 
  last 
  statement, 
  inquiry 
  may 
  be 
  made 
  as 
  to 
  the 
  

   condition 
  of 
  the 
  source 
  of 
  supply. 
  In 
  answer 
  it 
  may 
  be 
  said 
  

   that 
  the 
  field 
  is 
  practically 
  inexhaustible. 
  At 
  present 
  only 
  the 
  

   most 
  accessible 
  points 
  are 
  worked. 
  With 
  the 
  improvement 
  of 
  

   roads 
  and 
  the 
  increased 
  demand 
  for 
  stone 
  still 
  other 
  quarries 
  

   will 
  be 
  opened. 
  In 
  the 
  Catskills, 
  along 
  the 
  line 
  of 
  the 
  Ulster 
  

  

  * 
  "Building 
  Stones 
  in 
  New 
  Yoi*k," 
  bj 
  J. 
  C. 
  Smock, 
  Bulletin 
  New 
  York 
  State 
  Museum, 
  vol. 
  ?, 
  

   No. 
  10, 
  1890. 
  

  

  