﻿224 
  B. 
  S. 
  Tarr 
  — 
  Arctic 
  Sea 
  Ice 
  as 
  a 
  Geological 
  Agent 
  

  

  able 
  to 
  discharge 
  its 
  cargo, 
  would 
  be 
  obliged 
  to 
  push 
  farther 
  

   out 
  to 
  sea. 
  The 
  sea-ice 
  is 
  made 
  in 
  winter 
  ; 
  the 
  glacier 
  ice 
  is 
  

   mainly 
  supplied 
  in 
  summer. 
  During 
  the 
  spring 
  and 
  early 
  

   summer 
  the 
  movement 
  of 
  the 
  sea-made 
  ice 
  is 
  active, 
  and 
  then, 
  

   when 
  it 
  has 
  disappeared, 
  its 
  place 
  is 
  taken 
  by 
  the 
  supply 
  from 
  

   the 
  glacier. 
  

  

  Influence 
  of 
  sea-made 
  ice 
  on 
  erosion. 
  — 
  The 
  sea-made 
  ice 
  of 
  

   winter, 
  covering 
  the 
  bays 
  from 
  shore 
  to 
  shore, 
  protects 
  the 
  

   coast 
  from 
  the 
  action 
  of 
  waves, 
  and 
  hence 
  for 
  the 
  greater 
  

   part 
  of 
  the 
  year 
  prohibits 
  this 
  form 
  of 
  erosion. 
  Even 
  when 
  

   the 
  ice 
  is 
  broken 
  up 
  and 
  floating 
  away, 
  it 
  protects 
  in 
  nearly 
  

   the 
  same 
  manner 
  ; 
  for 
  the 
  ice 
  cakes 
  and 
  floes 
  prevent 
  waves 
  

   from 
  forming, 
  and 
  destroy 
  those 
  that 
  have 
  already 
  been 
  formed 
  

   elsewhere. 
  Even 
  when 
  the 
  wind 
  was 
  blowing, 
  while 
  our 
  ship 
  

   was 
  in 
  the 
  open 
  sea 
  off 
  the 
  Labrador 
  coast, 
  there 
  was 
  only 
  

   an 
  almost 
  imperceptible 
  swell, 
  the 
  remnants 
  of 
  the 
  nearly 
  

   destroyed 
  waves 
  of 
  the 
  ice-free, 
  open 
  water. 
  However, 
  when 
  

   the 
  ice 
  cakes 
  are 
  more 
  scattered, 
  the 
  waves 
  use 
  them 
  as 
  effec- 
  

   tive 
  tools, 
  hurling 
  them 
  against 
  the 
  coast 
  and 
  grinding 
  them 
  

   up 
  and 
  down 
  upon 
  it. 
  Moreover 
  in 
  the 
  last 
  stages 
  a 
  rim 
  of 
  ice 
  

   clings 
  firmly 
  to 
  the 
  rock 
  at 
  high-tide 
  mark, 
  and 
  no 
  doubt 
  the 
  

   waves 
  use 
  this 
  in 
  places 
  as 
  a 
  means 
  of 
  prying 
  off 
  fragments 
  of 
  

   rock. 
  

  

  It 
  would 
  be 
  difficult 
  to 
  balance 
  the 
  protective 
  and 
  destruc- 
  

   tive 
  action 
  of 
  this 
  sea 
  ice, 
  but 
  I 
  believe 
  on 
  the 
  whole 
  that 
  the 
  

   average 
  is 
  in 
  favor 
  of 
  protection. 
  Nevertheless 
  the 
  ice 
  is 
  used 
  

   as 
  a 
  very 
  effective 
  tool, 
  not 
  merely 
  by 
  the 
  action 
  of 
  the 
  waves, 
  

   which 
  hurl 
  the 
  individual 
  blocks 
  against 
  the 
  shore, 
  but 
  chiefly 
  

   by 
  the 
  grinding 
  action 
  of 
  the 
  tide. 
  As 
  the 
  water 
  rises 
  and 
  

   falls 
  the 
  ice 
  is 
  constantly 
  ground 
  against 
  the 
  shore, 
  and 
  that 
  as 
  

   a 
  result 
  of 
  this 
  it 
  is 
  doing 
  much 
  work 
  is 
  oftentimes 
  clearly 
  

   illustrated. 
  Nowhere 
  was 
  this 
  better 
  seen 
  during 
  my 
  visit 
  to 
  

   the 
  Arctic 
  than 
  on 
  the 
  southern 
  side 
  of 
  Baffin 
  Land 
  in 
  White 
  

   Strait. 
  There 
  the 
  tide 
  rises 
  about 
  thirty 
  feet, 
  and 
  the 
  mud 
  flats,, 
  

   when 
  exposed 
  to 
  view 
  at 
  low 
  tide, 
  were 
  seen 
  to 
  be 
  pitted 
  and 
  

   gouged 
  in 
  a 
  manner 
  quite 
  closely 
  resembling 
  the 
  surface 
  of 
  the 
  

   mud 
  flats 
  on 
  the 
  Massachusetts 
  coast 
  after 
  the 
  clam 
  diggers 
  

   have 
  left 
  them. 
  Carried 
  in 
  by 
  the 
  tide, 
  the 
  ice 
  cakes 
  strike 
  

   against 
  the 
  muddy 
  bottom 
  and 
  dig 
  a 
  hole, 
  thus 
  stirring 
  up 
  con- 
  

   siderable 
  mud, 
  which 
  is 
  driven 
  about 
  by 
  the 
  tidal 
  currents- 
  

   Stranded 
  cakes 
  were 
  everywhere 
  present, 
  and 
  that 
  they 
  were 
  

   engaged 
  in 
  the 
  transportation 
  of 
  rock 
  material 
  was 
  often 
  

   shown 
  by 
  the 
  presence 
  of 
  good-sized 
  bowlders, 
  deeply 
  embed- 
  

   ded 
  in 
  the 
  mud, 
  where 
  they 
  had 
  been 
  dropped 
  by 
  the 
  melting 
  

   of 
  the 
  ice. 
  

  

  In 
  this 
  same 
  region 
  the 
  grinding 
  and 
  transporting 
  action 
  of 
  

   the 
  ice 
  was 
  shown 
  by 
  the 
  bowlder 
  beaches. 
  At 
  the 
  head 
  of 
  

  

  