﻿424 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  done. 
  Because 
  of 
  the 
  simplicity 
  of 
  the 
  means 
  employed 
  these 
  

   mills 
  have 
  evident 
  advantages. 
  

  

  A 
  rather 
  singular 
  omission 
  in 
  American 
  grinding 
  plants 
  is 
  the 
  

   absence 
  of 
  separators. 
  In 
  gradual 
  reduction 
  of 
  materials 
  the 
  

   use 
  of 
  separators 
  to 
  remove 
  the 
  fine 
  stuff 
  before 
  the 
  material 
  

   passes 
  to 
  the 
  mills 
  is 
  advantageous, 
  because 
  it 
  relieves 
  the 
  mills 
  

   of 
  that 
  much 
  material 
  and 
  increases 
  their 
  output. 
  Wind 
  sepa- 
  

   rators 
  are 
  very 
  generally 
  used 
  abroad, 
  but 
  are 
  not 
  common 
  here. 
  

  

  The 
  fineness 
  of 
  the 
  best 
  American 
  cements 
  is 
  unsurpassed 
  in 
  

   any 
  practice 
  and 
  as 
  a 
  general 
  average 
  is 
  superior 
  to 
  foreign-made 
  

   cements. 
  The 
  following 
  table 
  gives 
  some 
  comparative 
  figures 
  

   in 
  this 
  respect: 
  

  

  % 
  passing 
  Bleres 
  

   no. 
  50 
  no. 
  100 
  no. 
  200 
  

  

  Saylors 
  100 
  96.4 
  . 
  

  

  Giant 
  99 
  94.9 
  . 
  

  

  Atlas 
  99.5 
  92.7 
  . 
  

  

  Alpha 
  ....' 
  99.7 
  94.8 
  . 
  

  

  Vulcanite 
  99.6 
  95.3 
  

  

  Sandusky 
  99.6 
  92.8 
  . 
  

  

  Brooks, 
  Shoebridge 
  & 
  Co 
  98.8 
  88.3 
  , 
  

  

  Aslen 
  99.7 
  92.4 
  68 
  

  

  Dyckerhoff 
  

  

  Aalborg 
  100 
  99.6 
  72 
  

  

  Germania 
  

  

  Condor 
  '.■ 
  99.6 
  88.5 
  

  

  Criteria 
  of 
  quality 
  

   The 
  only 
  standards 
  in 
  testing 
  cements 
  which 
  command 
  any 
  

   general 
  recognition 
  in 
  America 
  are 
  the 
  recommendations 
  of 
  a 
  

   committee 
  of 
  the 
  American 
  society 
  of 
  civil 
  engineers. 
  The 
  re- 
  

   ports 
  of 
  these 
  committees 
  are 
  found 
  in 
  no. 
  276 
  and 
  315 
  of 
  the 
  

   society's 
  transactions. 
  The 
  work 
  of 
  this 
  committee 
  has 
  estab- 
  

   lished 
  practice 
  on 
  the 
  following 
  points: 
  1) 
  the 
  form 
  and 
  section 
  

   of 
  test 
  briquettes; 
  2) 
  a 
  standard 
  quality 
  of 
  sand; 
  3) 
  standard 
  

   sieves 
  for 
  sand; 
  4) 
  standard 
  sieves 
  for 
  determining 
  fineness 
  of 
  

   cements; 
  5) 
  the 
  rate 
  of 
  speed 
  in 
  applying 
  stress 
  in 
  testing 
  (400 
  

  

  