﻿840 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  terms 
  " 
  frazil 
  " 
  and 
  " 
  anchor 
  ice 
  " 
  have 
  been 
  used 
  synonymously, 
  

   and 
  are 
  apparently 
  often 
  understood 
  as 
  the 
  French 
  and 
  English 
  

   words 
  for 
  the 
  same 
  thing, 
  but 
  the 
  following 
  from 
  the 
  report 
  of 
  

   the 
  Montreal 
  Flood 
  Commission 
  of 
  1890 
  will 
  serve 
  to 
  define 
  the 
  

   difference. 
  According 
  to 
  this 
  report, 
  frazil 
  is 
  formed 
  over 
  the 
  

   whole 
  unfrozen 
  surface 
  wherever 
  there 
  is 
  sufficient 
  current 
  or 
  

   wind 
  agitation 
  to 
  prevent 
  the 
  formation 
  of 
  border 
  ice; 
  whereas 
  

   the 
  term 
  anchor 
  ice 
  includes 
  only 
  such 
  ice 
  as 
  is 
  found 
  attached 
  

   to 
  the 
  bottom. 
  Frazil 
  is 
  frequently 
  misused 
  by 
  being 
  made 
  to 
  

   include 
  ice 
  formed 
  on 
  the 
  bottom, 
  as 
  well 
  as 
  throughout 
  the 
  mass 
  

   and 
  on 
  the 
  surface 
  of 
  a 
  river, 
  although 
  properly 
  it 
  should 
  be 
  only 
  

   applied 
  to 
  floating 
  ice. 
  The 
  common 
  theory 
  has 
  been 
  that 
  anchor 
  

   ice 
  first 
  forms 
  on 
  the 
  bottom, 
  subsequently 
  rising. 
  The 
  Montreal 
  

   studies, 
  however, 
  show 
  that 
  this 
  is 
  hardly 
  true. 
  At 
  times 
  the 
  

   whole 
  mass 
  of 
  water 
  from 
  surface 
  to 
  bottom 
  is 
  filled 
  with 
  fine 
  

   needles 
  which 
  actually 
  form 
  throughout 
  the 
  water 
  mass 
  itself. 
  

  

  As 
  to 
  the 
  remedy, 
  the 
  studies 
  are 
  hardly 
  complete 
  enough 
  to 
  

   indicate 
  the 
  best 
  course 
  to 
  pursue. 
  As 
  practical 
  hints, 
  it 
  may 
  be 
  

   stated 
  that 
  in 
  locating 
  dams 
  on 
  streams 
  specially 
  subject 
  to 
  this 
  

   difficulty 
  they 
  should 
  be 
  placed 
  with 
  reference 
  to 
  as 
  long 
  a 
  

   stretch 
  of 
  backwater 
  and 
  as 
  great 
  depth 
  as 
  possible, 
  all 
  the 
  

   studies 
  thus 
  far 
  made 
  tending 
  to 
  show 
  that 
  the 
  formation 
  is 
  most 
  

   extensive 
  in 
  shallow, 
  rapid-flowing 
  water. 
  Usually, 
  trouble 
  from 
  

   frazil 
  and 
  anchor 
  ice 
  extends 
  through 
  a 
  period 
  of 
  a 
  day 
  or 
  two; 
  

   and 
  at 
  very 
  important 
  plants, 
  where 
  even 
  a 
  short 
  interruption 
  

   would 
  be 
  a 
  serious 
  matter, 
  arrangements 
  may 
  be 
  made 
  for 
  using 
  

   steam 
  at 
  the 
  headworks 
  for 
  keeping 
  the 
  racks 
  open. 
  This 
  plan 
  

   has 
  been 
  successfully 
  pursued 
  at 
  the 
  waterworks 
  intakes 
  of 
  several 
  

   of 
  the 
  Great 
  Lake 
  cities. 
  In 
  the 
  case 
  of 
  power 
  plants, 
  where 
  much 
  

   larger 
  quantities 
  of 
  water 
  are 
  required 
  and 
  the 
  stream 
  flows 
  with 
  

   greater 
  velocity, 
  the 
  amount 
  of 
  steam 
  required 
  may 
  be 
  very 
  large. 
  1 
  

  

  x 
  For 
  literature 
  of 
  frazil 
  and 
  anchor 
  ice 
  see 
  (1) 
  Report 
  of 
  the 
  Montreal 
  

   Flood 
  Commissioners 
  of 
  1886; 
  (2) 
  Reports 
  of 
  the 
  Harbor 
  Commissioners 
  of 
  

   Montreal 
  for 
  the 
  years 
  1885, 
  1887, 
  and 
  1895; 
  (3) 
  Paper 
  on 
  Frazil 
  Ice 
  and 
  

   Its 
  Nature, 
  and 
  the 
  Prevention 
  of 
  Its 
  Actions 
  in 
  Causing 
  Floods, 
  by 
  George 
  

   H. 
  Henshaw, 
  Trans. 
  Can. 
  Soc. 
  C. 
  E. 
  Vol. 
  I, 
  Part 
  I, 
  p. 
  1-23 
  ; 
  and 
  (4) 
  Paper 
  

   on 
  the 
  Formation 
  and 
  Agglomeration 
  of 
  Frazil 
  and 
  Anchor 
  Ice, 
  by 
  Howard 
  

   T. 
  Barnes, 
  in 
  Canadian 
  Engineer, 
  Vol. 
  V 
  (May, 
  1897). 
  

  

  