﻿40 
  Transactions. 
  — 
  Miscellaneous. 
  

  

  adoption 
  of 
  a 
  general 
  sj^stem 
  of 
  main 
  drainage. 
  The 
  metropolis 
  liad 
  

   suffered 
  severely 
  in 
  the 
  cholera 
  visitation 
  of 
  1831-2, 
  again 
  in 
  1848-9, 
  and 
  

   lastly 
  in 
  1853-4." 
  " 
  The 
  places 
  formerly 
  most 
  favourable 
  to 
  the 
  spread 
  of 
  

   the 
  disease 
  became 
  quite 
  free 
  from 
  it 
  when 
  afterwards 
  properly 
  drained." 
  

  

  Again 
  : 
  " 
  In 
  designing 
  a 
  system 
  of 
  main 
  di-ainage 
  these 
  points 
  had 
  to 
  be 
  

   kept 
  in 
  view 
  — 
  to 
  provide 
  ample 
  means 
  for 
  the 
  discharge 
  of 
  the 
  large 
  and 
  

   increasing 
  water 
  su]Dply 
  consequent 
  on 
  the 
  universal 
  adoption 
  of 
  water- 
  

   closets, 
  and 
  of 
  the 
  ordinary 
  rainfall 
  and 
  surface 
  drainage 
  at 
  all 
  times, 
  

   except 
  during 
  extraordinary 
  storms, 
  and 
  to 
  afford 
  to 
  the 
  low-lying 
  dis- 
  

   tricts 
  a 
  sufficiently 
  deep 
  outfall 
  to 
  allow 
  of 
  every 
  house 
  being 
  effectually 
  

   relieved 
  of 
  its 
  fluid 
  refuse." 
  

  

  Again 
  : 
  " 
  For 
  centuries 
  there 
  had 
  existed 
  Sewers 
  Commissions 
  appointed 
  

   by 
  the 
  Government, 
  and 
  irresponsible 
  to 
  the 
  ratepayers, 
  upon 
  whom 
  they 
  

   levied 
  rates." 
  " 
  The 
  author 
  (Sir 
  J. 
  W. 
  Bazalgette) 
  having 
  been 
  appointed 
  

   engineer 
  to 
  the 
  Metropolitan 
  Board 
  was 
  again 
  instructed 
  to 
  prepare 
  a 
  plan 
  

   for 
  the 
  di'ainage 
  of 
  the 
  metropolis 
  ; 
  " 
  " 
  and 
  it 
  was 
  through 
  the 
  influence 
  of 
  

   Lord 
  John 
  Manners 
  that 
  the 
  Board 
  was 
  left 
  free 
  to 
  carry 
  out 
  then- 
  system 
  

   of 
  main 
  di-ainage." 
  

  

  Again 
  : 
  "The 
  objects 
  sought 
  to 
  be 
  attained 
  in 
  the 
  execution 
  of 
  the 
  main 
  

   drainage 
  works 
  were 
  — 
  the 
  interception 
  of 
  the 
  sewage 
  (as 
  far 
  as 
  practicable 
  by 
  

   gravitation), 
  together 
  with 
  so 
  much 
  of 
  the 
  rainfall 
  mixed 
  with 
  it 
  as 
  could 
  be 
  

   reasonably 
  dealt 
  with, 
  so 
  as 
  to 
  divert 
  it 
  from 
  the 
  river 
  at 
  London; 
  the 
  

   substitution 
  of 
  a 
  constant, 
  instead 
  of 
  an 
  intermittent 
  flow 
  in 
  the 
  sewers 
  ; 
  

   the 
  abolition 
  of 
  stagnant 
  and 
  tide-locked 
  sewers, 
  with 
  their 
  consequent 
  

   accumulations 
  of 
  deposit 
  ; 
  and 
  the 
  provision 
  of 
  deep 
  and 
  unproved 
  outfalls 
  

   for 
  the 
  extension 
  of 
  the 
  sewage 
  into 
  districts 
  previously, 
  for 
  want 
  of 
  such 
  

   outfalls, 
  imperfectly 
  drained." 
  

  

  Again 
  : 
  " 
  According 
  to 
  the 
  system 
  it 
  was 
  sought 
  to 
  improve; 
  the 
  London 
  

   main 
  sewers 
  fell 
  into 
  the 
  Thames, 
  and, 
  most 
  of 
  them 
  passing 
  under 
  the 
  low 
  

   grounds 
  in 
  the 
  margin 
  of 
  the 
  river 
  before 
  they 
  reached 
  it, 
  discharged 
  their 
  

   contents 
  into 
  that 
  river 
  at 
  or 
  about 
  the 
  level, 
  and 
  at 
  the 
  time 
  of 
  low 
  water 
  

   only. 
  As 
  the 
  tide 
  rose 
  it 
  closed 
  the 
  outlets 
  and 
  ponded 
  back 
  the 
  sewage 
  

   flowing 
  from 
  the 
  high 
  ground." 
  

  

  " 
  The 
  volume 
  of 
  pure 
  water 
  in 
  the 
  river 
  (Thames) 
  being 
  at 
  that 
  time 
  at 
  

   its 
  minimum 
  rendered 
  it 
  quite 
  incapable 
  of 
  diluting 
  and 
  disinfecting 
  such 
  

   vast 
  masses 
  of 
  sewage." 
  

  

  Again 
  : 
  " 
  In 
  the 
  system 
  now 
  adopted 
  it 
  has 
  been 
  sought 
  to 
  remove 
  those 
  

   evils 
  by 
  the 
  construction 
  of 
  new 
  lines 
  of 
  sewers 
  laid 
  at 
  right 
  angles 
  to 
  

   those 
  existing, 
  and 
  a 
  Httle 
  below 
  their 
  levels, 
  so 
  as 
  to 
  intercept 
  their 
  

   contents 
  and 
  convey 
  them 
  to 
  an 
  outfaU 
  fourteen 
  miles 
  below 
  London 
  

   Bridge/' 
  

  

  