﻿Thomson. 
  — 
  On 
  the 
  Cleansing 
  of 
  Toums. 
  61 
  

  

  cii'culated 
  with 
  the 
  authority 
  of 
  a 
  responsible 
  public 
  body, 
  it 
  is 
  impossible 
  

   to 
  overrate 
  the 
  grave 
  importance 
  which 
  attaches 
  to 
  such 
  statements 
  " 
  as 
  are 
  

   contained 
  therein. 
  

  

  Again: 
  The 
  Engineer 
  states 
  that, 
  "in 
  order 
  to 
  simplify 
  the 
  subject 
  as 
  far 
  

   as 
  possible, 
  we 
  propose 
  to 
  direct 
  our 
  enquiry 
  to 
  the 
  following 
  points, 
  viz. 
  : 
  — 
  

  

  "1st. 
  Whether 
  there 
  is 
  any 
  evidence 
  that 
  foul 
  and 
  offensive 
  accretions 
  

   have 
  formed 
  within 
  the 
  channel 
  of 
  the 
  Thames 
  since 
  the 
  metropohtan 
  

   sewage 
  outfalls 
  came 
  into 
  operation. 
  

  

  " 
  2nd. 
  Whether 
  careful 
  analyses 
  do 
  show 
  a 
  perfect 
  identity 
  between 
  the 
  

   constituents 
  of 
  the 
  Thames 
  mud 
  and 
  those 
  of 
  the 
  metropohtan 
  sewage. 
  

  

  " 
  8rd. 
  Whether 
  it 
  is 
  true 
  that 
  the 
  sewage 
  discharged 
  at 
  Barking 
  and 
  

   Crossness 
  does 
  work 
  its 
  way 
  upwards, 
  and 
  cause 
  the 
  same 
  pollution 
  of 
  the 
  

   Thames 
  within 
  and 
  about 
  the 
  metropolitan 
  area 
  as 
  formerly 
  existed. 
  

  

  " 
  4th. 
  As 
  to 
  the 
  quantity 
  of 
  solid 
  matter 
  contained 
  in 
  the 
  sewage 
  dis- 
  

   charged 
  into 
  the 
  Thames 
  at 
  Barking 
  and 
  Crossness, 
  and 
  whether 
  it 
  is 
  suffi- 
  

   cient 
  to 
  produce 
  any 
  sensible 
  deposit 
  in 
  the 
  bed 
  of 
  the 
  river, 
  and 
  as 
  to 
  the 
  

   real 
  cause 
  of 
  such 
  deposit." 
  

  

  As 
  to 
  the 
  recent 
  formation 
  of 
  foul 
  and 
  offensive 
  accretions, 
  the 
  Engineer 
  

   argues 
  that 
  comparison 
  of 
  the 
  state 
  of 
  the 
  river 
  thu'ty 
  years 
  previous 
  to 
  

   1861, 
  and 
  that 
  in 
  fifteen 
  subsequent 
  years, 
  has 
  " 
  no 
  value 
  or 
  significance 
  

   whatever." 
  Fm'ther, 
  when 
  it 
  is 
  considered 
  that 
  the 
  traverse 
  sectional 
  areas 
  

   of 
  the 
  river 
  taken 
  at 
  half-tide 
  off 
  the 
  Crossness 
  outfaU 
  have 
  been 
  increased 
  

   by 
  the 
  removal 
  of 
  shoals," 
  &c., 
  " 
  it 
  would 
  be 
  no 
  matter 
  of 
  siu'prise 
  if 
  the 
  

   river 
  in 
  this 
  part 
  of 
  its 
  course 
  should 
  be 
  even 
  more 
  hable 
  to 
  partial 
  deposits 
  

   forming 
  upon 
  the 
  banks 
  than 
  it 
  was 
  formerly." 
  

  

  He 
  then 
  enters 
  into 
  the 
  subject 
  of 
  the 
  Woolwich 
  shoals, 
  and 
  concludes 
  

   "that 
  it 
  is 
  obviously 
  impossible 
  to 
  draw 
  the 
  conclusion 
  which 
  Captain 
  Calver 
  

   suggests, 
  that 
  because 
  mud 
  is 
  found 
  in 
  this 
  part 
  of 
  the 
  river, 
  therefore 
  it 
  

   comes 
  from 
  the 
  metropohtan 
  sewers." 
  Then 
  as 
  to 
  the 
  mud 
  deposits 
  higher 
  

   up, 
  near 
  Waterloo 
  Bridge, 
  he 
  remarks 
  " 
  that 
  it 
  is 
  obvious 
  that 
  the 
  deposits 
  

   of 
  mud 
  above 
  referred 
  to, 
  and 
  which, 
  it 
  appears, 
  accumulated 
  in 
  a 
  few 
  

   months 
  time, 
  could 
  not 
  have 
  resulted 
  from 
  the 
  sewage 
  discharged 
  into 
  

   the 
  river 
  upon 
  the 
  ebb-tide 
  at 
  a 
  point 
  no 
  less 
  than 
  14^ 
  miles 
  lower 
  down 
  

   the 
  stream." 
  

  

  Next, 
  as 
  to 
  the 
  identity 
  of 
  Thames 
  mud 
  with 
  sewage 
  mud, 
  the 
  Engineer 
  

   endeavours 
  to 
  show 
  the 
  fallacy 
  of 
  much 
  of 
  Captain 
  Calver's 
  arguments. 
  

   This 
  is 
  illustrated 
  by 
  a 
  table, 
  from 
  which 
  he 
  (the 
  Engineer) 
  surmises 
  that 
  

   "it 
  is 
  perfectly 
  obvious 
  that 
  no 
  conclusion 
  can 
  be 
  possibly 
  true 
  which 
  is 
  

   founded 
  upon 
  the 
  supposed 
  ' 
  perfect 
  identity 
  ' 
  of 
  quantities 
  which 
  vary 
  from 
  

   0-85 
  to 
  40-91," 
  

  

  