﻿Thomson. 
  — 
  On 
  the 
  Cleansing 
  of 
  Towns. 
  69 
  

  

  In 
  reference 
  to 
  the 
  deleterious 
  effect 
  of 
  sewage 
  discharged 
  into 
  a 
  tidal 
  

   river, 
  from 
  various 
  experiments, 
  Captain 
  Calver 
  concludes 
  that 
  "it 
  will 
  be 
  

   seen 
  that 
  it 
  matters 
  not 
  whether 
  the 
  sewage 
  be 
  sent 
  into 
  the 
  river 
  at 
  low- 
  

   water 
  at 
  London, 
  or 
  at 
  high- 
  water 
  at 
  Barking 
  Creek 
  and 
  Crossness, 
  for 
  the 
  

   result 
  is 
  one 
  and 
  the 
  same. 
  The 
  matter 
  from 
  the 
  sewers 
  will 
  work 
  its 
  way 
  

   upwards, 
  and 
  form 
  accumulations 
  above 
  the 
  outfalls 
  both 
  in 
  the 
  bed 
  and 
  

   along 
  the 
  sides 
  of 
  the 
  channel." 
  

  

  Again 
  : 
  As 
  to 
  the 
  theory 
  which 
  erroneously 
  assigns 
  deepening 
  to 
  the 
  

   credit 
  of 
  sewage 
  discharge. 
  This 
  is 
  said 
  to 
  be 
  due 
  " 
  to 
  two 
  very 
  different 
  

   causes 
  — 
  viz., 
  to 
  the 
  dredging 
  carried 
  on 
  in 
  the 
  district, 
  and 
  to 
  the 
  scour 
  

   resulting 
  from 
  the 
  removal 
  of 
  impediments 
  out 
  of 
  the 
  channel 
  in 
  higher 
  

   portions 
  of 
  the 
  river." 
  Dredging, 
  also, 
  is 
  stated 
  to 
  have 
  removed 
  

   " 
  enormous 
  hills 
  of 
  gravel 
  which 
  now 
  disfigure 
  and 
  encumber 
  the 
  banks 
  

   of 
  the 
  Tyne 
  and 
  Wear." 
  Another 
  cause 
  stated 
  as 
  tending 
  to 
  increase 
  

   the 
  depth 
  of 
  Mid-Thames 
  resides 
  in 
  the 
  removal 
  of 
  the 
  old 
  bridge 
  at 
  

   London, 
  and 
  the 
  dredging 
  that 
  has 
  taken 
  place 
  as 
  high 
  up 
  as 
  Isleworth. 
  

  

  Again 
  : 
  " 
  As 
  matters 
  now 
  stand, 
  the 
  Metropohtan 
  sewage 
  discharge 
  has 
  

   reproduced 
  in 
  Mid- 
  Thames, 
  in 
  an 
  aggravated 
  form, 
  a 
  nuisance 
  which 
  was 
  

   felt 
  to 
  be 
  unbearable 
  in 
  the 
  upper 
  portion 
  of 
  the 
  river. 
  Formerly, 
  the 
  

   sewers 
  at 
  London 
  discharged 
  their 
  contents 
  into 
  the 
  river 
  at 
  low 
  water, 
  and 
  

   this. 
  Sir 
  Joseph 
  Bazalgette 
  has 
  pointed 
  out, 
  "was 
  most 
  injurious, 
  because 
  

   it 
  was 
  carried 
  by 
  the 
  rising 
  tide 
  up 
  the 
  river 
  to 
  be 
  brought 
  to 
  London 
  by 
  

   the 
  following 
  ebb-tide, 
  there 
  to 
  mix 
  with 
  each 
  day's 
  past 
  supply, 
  the 
  pro- 
  

   gress 
  of 
  many 
  days' 
  accumulations 
  towards 
  the 
  sea 
  being 
  almost 
  imper- 
  

   ceptible." 
  This 
  exactly 
  describes 
  the 
  existing 
  state 
  of 
  things 
  in 
  Mid-Thames, 
  

   both 
  in 
  respect 
  to 
  accumulation 
  of 
  sewage, 
  its 
  daily 
  oscillation, 
  and 
  its 
  slow 
  

   progress 
  seaward 
  ; 
  the 
  only 
  difference 
  now 
  is, 
  that 
  the 
  nuisance 
  which 
  was 
  

   formerly 
  brought 
  down 
  to 
  London 
  by 
  the 
  ebb 
  is 
  now 
  carried 
  up 
  to 
  London 
  

   by 
  the 
  flood." 
  

  

  Again: 
  "The 
  evidence 
  of 
  the 
  senses 
  may 
  also 
  be 
  relied 
  on 
  as 
  an 
  

   important 
  factor 
  for 
  determining 
  the 
  question 
  of 
  purity. 
  While 
  in 
  the 
  

   neighbourhood 
  of 
  the 
  outfalls, 
  I 
  observed 
  that 
  bubbles 
  of 
  gaseous 
  matter, 
  

   arising 
  from 
  decomposition, 
  were 
  continually 
  ascending 
  to 
  the 
  surface 
  of 
  the 
  

   ■water, 
  reminding 
  me 
  of 
  similar 
  experience 
  in 
  the 
  polluted 
  Clyde. 
  The 
  foul 
  

   condition 
  of 
  the 
  river 
  was 
  also 
  apparent 
  from 
  the 
  smell 
  caused 
  by 
  the 
  dis- 
  

   turbance 
  raised 
  by 
  the 
  steamers' 
  paddles 
  ; 
  and 
  the 
  floating 
  abominations 
  by 
  

   which 
  I 
  was 
  surrounded, 
  when 
  making 
  the 
  test 
  observations, 
  are 
  to 
  be 
  

   remembered 
  rather 
  than 
  described," 
  

  

  Again 
  : 
  " 
  Contemporary 
  and 
  rehable 
  opinions 
  are 
  all 
  opposed 
  to 
  the 
  

   practice 
  of 
  discharging 
  crude 
  sewage 
  into 
  rivers." 
  

  

  