﻿REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  LXXII1 
  

  

  damaging. 
  Chloride 
  of 
  lime, 
  0.04 
  to 
  0.005 
  percent 
  chlorine, 
  exerted 
  an 
  immediately 
  

   deadly 
  action 
  upon 
  tench, 
  while 
  trout 
  and 
  salmon 
  perished 
  in 
  the 
  presence 
  of 
  0.0008 
  

   per 
  cent 
  of 
  chlorine. 
  One 
  per 
  cent 
  of 
  hydrochloric 
  acid 
  kills 
  tench 
  and 
  trout. 
  Iron 
  

   and 
  alum 
  act 
  as 
  specific 
  poisons 
  upon 
  fishes. 
  Solution 
  of 
  caustic 
  lime 
  has 
  an 
  exceed- 
  

   ingly 
  violent 
  effect 
  upon 
  them. 
  Sodium 
  sulphide, 
  0.1 
  per 
  cent, 
  was 
  endured 
  by 
  teuch 
  

   for 
  30 
  minutes. 
  

  

  28. 
  — 
  BY 
  THE 
  USE 
  OF 
  FISHWAYS. 
  

  

  Fishway 
  over 
  the 
  Great 
  Falls. 
  — 
  Reference 
  has 
  been 
  made 
  to 
  this 
  work 
  

   in 
  previous 
  reports. 
  Since 
  then 
  a 
  site 
  has 
  been 
  selected 
  for 
  the 
  con- 
  

   struction 
  of 
  a 
  suitable 
  fishway 
  which 
  it 
  is 
  hoped 
  will 
  enable 
  shad 
  

   striped 
  bass, 
  and 
  other 
  food-fishes 
  to 
  ascend 
  to 
  the 
  upper 
  portion 
  of 
  the 
  

   Potomac. 
  

  

  A 
  plan 
  of 
  fishway, 
  suggested 
  by 
  Colonel 
  McDonald, 
  who 
  prepared 
  the 
  

   necessary 
  working 
  drawings 
  for 
  the 
  purpose, 
  was 
  adopted, 
  and 
  recom- 
  

   mended 
  to 
  the 
  Secretary 
  of 
  War 
  for 
  such 
  further 
  action 
  as 
  he 
  mioht 
  

   think 
  proper. 
  

  

  A 
  contract 
  having 
  been 
  given 
  out 
  by 
  direction 
  of 
  the 
  Secretary 
  of 
  

   War 
  for 
  constructing 
  the 
  fishway, 
  work 
  was 
  pushed 
  forward 
  during 
  the 
  

   summer 
  of 
  1885. 
  The 
  conditions 
  of 
  the 
  contract 
  required 
  the 
  entire 
  

   work 
  to 
  be 
  completed 
  on 
  October 
  31 
  of 
  the 
  present 
  year. 
  Five 
  sec- 
  

   tions 
  were 
  at 
  that 
  date 
  in 
  process 
  of 
  construction, 
  and 
  high 
  water 
  oc- 
  

   curring 
  at 
  about 
  that 
  time 
  found 
  none 
  of 
  the 
  six 
  sections 
  completed, 
  

   and 
  put 
  an 
  end 
  to 
  the 
  work 
  for 
  the 
  season. 
  

  

  The 
  lowest 
  or 
  sixth 
  section 
  was 
  most 
  advanced 
  toward 
  completion 
  ' 
  

   needing 
  only 
  the 
  setting 
  of 
  the 
  line 
  of 
  coping 
  provided 
  for 
  in 
  the 
  plans 
  

   and 
  specifications 
  to 
  insure 
  the 
  permanence 
  and 
  durability 
  of 
  the 
  con- 
  

   struction. 
  It 
  suffered 
  little 
  or 
  no 
  injury 
  from 
  the 
  floods 
  and 
  ice 
  of 
  the 
  

   winter, 
  and 
  needs 
  only 
  to 
  be 
  completed 
  as 
  planned 
  to 
  render 
  this 
  part 
  

   of 
  the 
  construction 
  permanent. 
  

  

  The 
  work 
  remaining 
  to 
  be 
  done 
  at 
  the 
  end 
  of 
  the 
  year 
  is 
  as 
  follows 
  : 
  

  

  (1) 
  Tue 
  erection 
  of 
  a 
  weir 
  dam, 
  about 
  40 
  feet 
  long 
  and 
  5 
  feet 
  hi«-h 
  

   from 
  the 
  abutment 
  of 
  the 
  fishway 
  to 
  the 
  opposite 
  shore, 
  the 
  object 
  of 
  this 
  

   being 
  to 
  regulate 
  and 
  control 
  the 
  supply 
  of 
  water 
  to 
  the 
  fishway, 
  and, 
  

   at 
  the 
  same 
  time, 
  to 
  provide 
  for 
  discharge 
  of 
  the 
  surplus 
  water. 
  

  

  (2) 
  To 
  clear 
  out 
  the 
  channel 
  below 
  the 
  weir 
  dam, 
  so 
  that 
  the 
  water 
  

   flowing 
  over 
  the 
  dam 
  may 
  be 
  discharged 
  into 
  the 
  river 
  below 
  by 
  the 
  

   side 
  of 
  the 
  fishway, 
  instead 
  of 
  over 
  the 
  lower 
  end, 
  as 
  is 
  now 
  the 
  case. 
  

  

  (3) 
  The 
  placing 
  and 
  securing 
  of 
  the 
  12-inch 
  coping 
  to 
  cover 
  the 
  

   rubble 
  masonry 
  walls 
  forming 
  the 
  sides 
  of 
  the 
  fishway. 
  

  

  (4) 
  The 
  removal 
  of 
  the 
  loose 
  rock 
  piles 
  up 
  at 
  the 
  lower 
  end 
  of 
  the 
  

   fishway 
  and 
  excluding 
  fish 
  from 
  access 
  to 
  it. 
  

  

  The 
  matter 
  will 
  be 
  brought 
  to 
  the 
  attention 
  of 
  the 
  Secretary 
  of 
  War 
  

   in 
  the 
  spring 
  of 
  1S86 
  with 
  the 
  request 
  that 
  at 
  least 
  section 
  6 
  be 
  com- 
  

   pleted 
  at 
  once. 
  An 
  additional 
  appropriation 
  may 
  be 
  required 
  for 
  com- 
  

   pleting 
  the 
  other 
  sections. 
  

  

  