﻿Taylor 
  — 
  Scoured 
  Bowlders 
  of 
  the 
  Mattawa 
  Valley. 
  217 
  

  

  tion 
  and 
  tapers 
  smoothly 
  up 
  to 
  a 
  point 
  about 
  two 
  inches 
  

   through. 
  Its 
  shape 
  may 
  perhaps 
  be 
  best 
  described 
  by 
  saying 
  

   that 
  it 
  is 
  like 
  an 
  Irish 
  peasant's 
  hat. 
  The 
  crown 
  is 
  rather 
  

   pointed 
  and 
  the 
  rim 
  projects 
  downward 
  and 
  outward 
  from 
  it 
  

   through 
  a 
  very 
  gentle 
  curve. 
  The 
  base 
  or 
  bottom 
  of 
  this 
  stone 
  

   is 
  flat 
  and 
  smooth 
  and 
  showed 
  no 
  rough 
  surface 
  where 
  it 
  might 
  

   have 
  been 
  detached 
  from 
  the 
  solid 
  mass. 
  From 
  similar 
  speci- 
  

   mens 
  seen 
  before, 
  the 
  writer 
  at 
  once 
  recognized 
  this 
  stone 
  as 
  

   the 
  detached 
  core 
  of 
  a 
  pothole. 
  It 
  is 
  about 
  ten 
  inches 
  high 
  

   and 
  rather 
  narrow 
  and 
  slender, 
  and 
  hence 
  suggests 
  a 
  pothole 
  of 
  

   relatively 
  great 
  depth. 
  But 
  the 
  edges 
  around 
  the 
  base 
  or 
  rim 
  

   are 
  also 
  apparently 
  worn 
  smooth. 
  This 
  makes 
  it 
  very 
  difficult 
  

   to 
  account 
  fully 
  for 
  its 
  origin. 
  It 
  seems 
  probable 
  that 
  this 
  

   stone 
  was 
  bored 
  out 
  of 
  a 
  solid 
  bowlder. 
  In 
  that 
  case 
  it 
  

   is 
  the 
  core 
  left 
  from 
  the 
  making 
  of 
  a 
  ring-bowlder. 
  The 
  

   bowlder 
  itself 
  might 
  have 
  been 
  smooth 
  on 
  its 
  bottom 
  before 
  

   the 
  making 
  of 
  the 
  pothole 
  began, 
  and 
  this 
  would 
  go 
  some 
  way 
  

   toward 
  explaining 
  the 
  smooth 
  bottom 
  of 
  the 
  core-stone. 
  Such 
  

   stones 
  as 
  this 
  might 
  be 
  set 
  down 
  as 
  an 
  independent 
  variety 
  of 
  

   scoured 
  bowlders. 
  But 
  so 
  little 
  was 
  learned 
  of 
  the 
  occurrence 
  

   of 
  this 
  specimen 
  that 
  its 
  place 
  and 
  manner 
  of 
  origin 
  seems 
  to 
  

   be 
  a 
  matter 
  of 
  some 
  doubt. 
  Nevertheless 
  its 
  smooth 
  and 
  

   apparently 
  fresh-polished 
  surface 
  suggests 
  that 
  it 
  is 
  a 
  scour 
  

   product 
  of 
  the 
  rapids 
  of 
  the 
  recent 
  great 
  outlet 
  river. 
  As 
  

   Dr. 
  Bell 
  has 
  suggested, 
  the 
  ring 
  bowlder 
  out 
  of 
  which 
  this 
  

   '•stone 
  hat" 
  or 
  core-stone 
  was 
  bored 
  may 
  be 
  lying 
  close 
  by 
  

   hidden 
  in 
  the 
  gravelly, 
  bowldery 
  surface 
  layer 
  (three 
  to 
  seven 
  

   or 
  eight 
  feet 
  deep), 
  which 
  covers 
  that 
  part 
  of 
  the 
  terrace. 
  Mr. 
  

   Macnab 
  pointed 
  out 
  another 
  curiously 
  hat-shaped 
  stone 
  on 
  a 
  

   veranda 
  in 
  the 
  village. 
  It 
  had 
  the 
  shape 
  of 
  a 
  " 
  sou'wester," 
  

   but 
  was 
  clearly 
  the 
  product 
  of 
  differential 
  weathering 
  (perhaps 
  

   afterwards 
  smoothed 
  in 
  the 
  rapids) 
  rather 
  than 
  of 
  scouring 
  by 
  

   current 
  action. 
  Dr. 
  Bell 
  deposited 
  the 
  first 
  mentioned 
  speci- 
  

   men 
  in 
  the 
  museum 
  at 
  Ottawa. 
  

  

  Summary. 
  

   Some 
  idea 
  of 
  the 
  magnitude 
  of 
  the 
  great 
  outlet 
  river 
  may 
  

   be 
  gathered 
  from 
  the 
  fact 
  that 
  at 
  Des 
  Epines 
  rapids 
  the 
  mark 
  

   of 
  its 
  upper 
  limit 
  is 
  quite 
  plain 
  at 
  50 
  to 
  55 
  feet 
  above 
  the 
  

   present 
  stream, 
  and 
  the 
  width 
  of 
  the 
  channel 
  at 
  that 
  height 
  is 
  

   between 
  600 
  and 
  TOO 
  feet. 
  The 
  average 
  depth 
  across 
  the 
  chan- 
  

   nel 
  is 
  35 
  to 
  40 
  feet, 
  and 
  yet 
  the 
  current 
  was 
  swift 
  enough 
  to 
  

   produce 
  many 
  of 
  the 
  finest 
  types 
  of 
  scoured 
  bowlders. 
  Here 
  

   and 
  in 
  Mattawa 
  there 
  are 
  other 
  bowlder 
  fields 
  as 
  heavily 
  cov- 
  

   ered 
  as 
  those 
  on 
  which 
  the 
  scoured 
  bowlders 
  are 
  found. 
  But 
  

   they 
  are 
  above 
  the 
  level 
  of 
  the 
  ancient 
  outlet 
  river, 
  and 
  

   although 
  they 
  were 
  examined 
  closely 
  no 
  scoured 
  bowlders 
  were 
  

   found 
  upon 
  them. 
  There 
  are 
  also 
  other 
  bowldery 
  tracts 
  at 
  low 
  

   levels 
  at 
  several 
  places 
  above 
  Mattawa. 
  But 
  they 
  are 
  situated 
  

  

  