﻿408 
  A. 
  W. 
  Duff 
  — 
  Seiches 
  on 
  the 
  Bay 
  of 
  Fundy. 
  

  

  ally 
  been 
  regarded 
  as 
  Laving 
  some 
  connection 
  with 
  the 
  tides 
  

   proper. 
  As 
  regards 
  the 
  35-seconds 
  undulations 
  such 
  a 
  connec- 
  

   tion 
  was 
  clearly 
  impossible, 
  when 
  regard 
  was 
  had 
  to 
  their 
  very 
  

   brief 
  period. 
  They 
  evidently 
  could 
  not 
  be 
  forced 
  vibrations, 
  

   and 
  if 
  not 
  they 
  must 
  be 
  the 
  free 
  vibrations 
  of 
  some 
  semi-con- 
  

   fined 
  body 
  of 
  water. 
  Now 
  this 
  body 
  could 
  only 
  be 
  the 
  small 
  

   bay 
  into 
  which 
  the 
  river 
  expands 
  at 
  Indiantown, 
  nearly 
  closed 
  

   above 
  by 
  a 
  part 
  called 
  the 
  Narrows, 
  and 
  below 
  by 
  the 
  narrow 
  

   outlet 
  referred 
  to. 
  This 
  suggested 
  at 
  once 
  that 
  the 
  slower 
  

   undulations 
  in 
  the 
  harbor 
  had 
  a 
  similar 
  origin, 
  namely, 
  that 
  

   they 
  were 
  the 
  free 
  vibrations 
  in 
  another 
  semi-confined 
  basin. 
  

   This 
  basin 
  could 
  not 
  be 
  the 
  harbor 
  itself. 
  Its 
  dimensions 
  are 
  

   about 
  those 
  of 
  the 
  small 
  bay 
  at 
  Indiantown, 
  and 
  its 
  time 
  of 
  

   free 
  swing 
  could 
  not 
  be 
  sixty 
  times 
  as 
  great. 
  The 
  only 
  other 
  

   basin 
  available 
  for 
  an 
  explanation 
  was 
  the 
  Bay 
  of 
  Fundy 
  

   itself, 
  limited 
  on 
  one 
  side 
  by 
  the 
  New 
  Brunswick 
  coast 
  and 
  

   on 
  the 
  other 
  by 
  the 
  Nova 
  Scotia 
  coast. 
  Hence 
  it 
  seemed 
  

   probable 
  that 
  the 
  " 
  secondary 
  undulations 
  " 
  in 
  the 
  harbor 
  

   were 
  the 
  free 
  vibrations 
  of 
  the 
  Bay 
  of 
  Fundy 
  along 
  a 
  line 
  

   from 
  St. 
  John 
  to 
  the 
  nearest 
  part 
  of 
  the 
  Nova 
  Scotia 
  coast. 
  

   The 
  rate 
  of 
  such 
  vibrations 
  depends 
  on 
  the 
  dimensions 
  of 
  the 
  

   basin, 
  and 
  this 
  provides 
  a 
  means 
  of 
  testing 
  the 
  above 
  theory. 
  

  

  Before 
  applying 
  this 
  test, 
  attention 
  may 
  be 
  called 
  to 
  some 
  

   similar 
  phenomena 
  observed 
  long 
  since 
  but 
  only 
  recently 
  come 
  

   to 
  my 
  knowledge. 
  For 
  a 
  great 
  many 
  years 
  certain 
  fluctuations 
  

   of 
  water 
  level 
  at 
  points 
  on 
  Lake 
  Geneva 
  were 
  known 
  and 
  pop- 
  

   ularly 
  called 
  seiches. 
  After 
  many 
  scattered 
  observations 
  by 
  

   Bertrand, 
  de 
  Saussure, 
  Vaucher 
  and 
  others, 
  a 
  thorough 
  study 
  

   of 
  the 
  subject 
  was 
  undertaken 
  by 
  Dr. 
  F. 
  A. 
  Forel, 
  whose 
  two 
  

   articles'* 
  give 
  a 
  complete 
  resume 
  of 
  the 
  subject. 
  Yaucher 
  had 
  

   found 
  that 
  the 
  seiches 
  were 
  most 
  common 
  in 
  changeable 
  

   weather, 
  with 
  a 
  low 
  barometer, 
  and 
  he 
  considered 
  them 
  to 
  be 
  

   due 
  to 
  merely 
  local 
  temperature 
  and 
  consequent 
  barometric 
  

   changes, 
  caused 
  by 
  rifts 
  in 
  clouds 
  and 
  variations 
  of 
  sunshine 
  on 
  

   the 
  lakes. 
  Forel 
  added 
  the 
  idea 
  that, 
  after 
  the 
  disturbance 
  of 
  

   equilibrium 
  produced 
  by 
  the 
  above 
  causes, 
  the 
  seiches 
  are 
  sim- 
  

   ply 
  the 
  subsequent 
  vibrations 
  of 
  the 
  whole 
  lake 
  about 
  its 
  equi- 
  

   librium 
  position. 
  This 
  theory 
  he 
  tested 
  by 
  making 
  observa- 
  

   tions 
  on 
  several 
  lakes 
  with 
  the 
  use 
  of 
  self-recording 
  gauges 
  and 
  

   proving 
  the 
  following 
  laws 
  :f 
  (1) 
  At 
  any 
  one 
  place 
  the 
  seiche 
  

   period 
  is 
  somewhat 
  variable, 
  but 
  the 
  mean 
  is 
  fairly 
  constant 
  ; 
  

   (2) 
  While 
  the 
  water 
  is 
  falling 
  at 
  one 
  side 
  of 
  a 
  lake 
  it 
  is 
  rising 
  

   at 
  the 
  opposite 
  side, 
  and 
  vice 
  versa 
  ; 
  (3) 
  The 
  period 
  in 
  the 
  

   different 
  lakes 
  varies 
  as 
  the 
  width, 
  and 
  inversely 
  as 
  the 
  square 
  

   root 
  of 
  the 
  depth. 
  He 
  even 
  predicted 
  a 
  depressed 
  area 
  in 
  

  

  * 
  Annales 
  de 
  Chimie 
  et 
  Physique, 
  ix, 
  1816. 
  

   f 
  Phil. 
  Mag., 
  Series 
  V, 
  vol. 
  ii, 
  1876. 
  

  

  