﻿MANUAL 
  OF 
  FISH-CULTURE. 
  129 
  

  

  two-thirds 
  coal 
  tar. 
  The 
  tar 
  should 
  be 
  as 
  warm 
  as 
  the 
  touch 
  will 
  hear, 
  

   and 
  the 
  turpeutine, 
  which 
  should 
  be 
  pure, 
  should 
  be 
  added 
  slowly 
  while 
  

   the 
  mass 
  is 
  being 
  vigorously 
  stirred. 
  The 
  mixture 
  dries 
  quickly 
  and 
  

   forms 
  a 
  hard, 
  durable 
  surface, 
  which 
  is 
  entirely 
  waterproof 
  and 
  much 
  

   more 
  lasting 
  than 
  asphaltum 
  ; 
  it 
  is 
  also 
  much 
  cheaper, 
  an 
  important 
  item 
  

   in 
  a 
  large 
  station. 
  While 
  applying 
  it 
  the 
  tin 
  j)ail 
  in 
  which 
  it 
  is 
  mixed 
  

   is 
  kept 
  in 
  another 
  and 
  larger 
  one 
  partly 
  filled 
  with 
  moderately 
  hot 
  

   water. 
  For 
  pitching 
  the 
  cracks 
  aiul 
  joints 
  the 
  best 
  asphaltum 
  pitch 
  is 
  

   used, 
  softened 
  with 
  parafiin 
  to 
  the 
  consistency 
  of 
  chewing-gum 
  — 
  that 
  

   is, 
  just 
  so 
  that 
  it 
  will 
  not 
  break 
  in 
  cold 
  water. 
  This 
  pitch 
  holds 
  firmly 
  

   to 
  the 
  wood 
  and 
  keeps 
  its 
  place 
  in 
  warm 
  weather. 
  Other 
  pitches 
  which 
  

   have 
  been 
  tried 
  will 
  run 
  in 
  warm 
  weather 
  and 
  get 
  hard 
  with 
  use, 
  

   breaking 
  when 
  cold. 
  

  

  THE 
  CARE 
  AND 
  PLANTING 
  OF 
  THE 
  FRY. 
  

  

  When 
  the 
  fry 
  hatch 
  they 
  immediately 
  leave 
  the 
  jar 
  and 
  follow 
  the 
  

   course 
  of 
  the 
  running 
  water, 
  some 
  going 
  through 
  the 
  succeeding 
  jars, 
  

   provided 
  there 
  are 
  no 
  screens 
  interposed 
  to 
  prevent 
  this, 
  others 
  through 
  

   the 
  overflows 
  from 
  the 
  cross-tanks, 
  until 
  all 
  reach 
  the 
  fry-collecting 
  

   tank 
  at 
  the 
  bottom, 
  whence 
  they 
  are 
  carried 
  to 
  the 
  main 
  collecting 
  

   tanks. 
  It 
  has 
  been 
  urged 
  by 
  some 
  that 
  it 
  is 
  injurious 
  for 
  the 
  fry 
  to 
  

   pass 
  down 
  through 
  the 
  lower 
  jars 
  with 
  the 
  complement 
  of 
  eggs, 
  but 
  in 
  

   practice 
  this 
  has 
  not 
  been 
  the 
  case. 
  

  

  An 
  air 
  -jet 
  on 
  the 
  inside 
  of 
  the 
  screens 
  will 
  prevent 
  clogging 
  by 
  the 
  

   accumulation 
  of 
  eggshells 
  aiul 
  impurities 
  suspended 
  in 
  the 
  water. 
  This 
  

   may 
  be 
  easily 
  arranged 
  by 
  providing 
  an 
  air-pump 
  and 
  connecting 
  with 
  

   it 
  a 
  pipe 
  carried 
  along 
  the 
  side 
  of 
  each 
  tank 
  on 
  the 
  inside 
  of 
  the 
  screen 
  

   and 
  thence 
  at 
  right 
  angles 
  parallel 
  to 
  the 
  screen 
  and 
  about 
  an 
  inch 
  

   distant. 
  This 
  cross-pipe 
  should 
  be 
  perforated 
  on 
  one 
  side 
  with 
  holes 
  

   -^ 
  inch 
  in 
  diameter 
  and 
  3 
  inches 
  apart, 
  the 
  holes 
  opening 
  toward 
  the 
  

   screen 
  and 
  upward 
  at 
  an 
  angle 
  of 
  about 
  45°. 
  When 
  the 
  air 
  is 
  turned 
  

   on, 
  an 
  apparently 
  solid 
  mass 
  of 
  bubbles 
  will 
  arise 
  along 
  the 
  whole 
  sur- 
  

   fiice 
  of 
  the 
  screen. 
  With 
  this 
  arrangement 
  the 
  screens 
  will 
  run 
  hours 
  

   or 
  even 
  days 
  without 
  any 
  attention, 
  whereas 
  without 
  the 
  air-jet 
  one 
  or 
  

   more 
  men 
  are 
  employed 
  keeping 
  the 
  screens 
  clean, 
  and 
  many 
  fry 
  are 
  

   unavoidably 
  killed 
  by 
  being 
  forced 
  against 
  the 
  screens 
  and 
  by 
  the 
  work 
  

   of 
  the 
  men 
  in 
  keeping 
  them 
  free. 
  The 
  thorough 
  aeration 
  of 
  the 
  water 
  

   thus 
  indirectly 
  accomi^lished 
  is 
  very 
  beneficial 
  when 
  large 
  numbers 
  of 
  

   fry 
  are 
  passing 
  over, 
  and 
  double 
  the 
  number 
  can 
  be 
  safely 
  handled 
  in 
  

   troughs 
  thus 
  equipped. 
  

  

  At 
  Put-in 
  Bay 
  the 
  fiy 
  are 
  planted 
  as 
  soon 
  as 
  hatched. 
  They 
  are 
  

   dipped 
  from 
  the 
  fry 
  tanks 
  into 
  kegs, 
  in 
  which 
  they 
  are 
  transported 
  to 
  

   the 
  natural 
  spawning- 
  grounds 
  on 
  the 
  reefs; 
  each 
  keg 
  containing 
  50,000 
  

   to 
  100,000 
  fry, 
  according 
  to 
  the 
  distance 
  to 
  be 
  traveled. 
  If 
  they 
  are 
  to 
  

   be 
  taken 
  any 
  considerable 
  distance, 
  fresh 
  water 
  is 
  kept 
  running 
  on 
  

   them. 
  If 
  the 
  facilities 
  are 
  such 
  that 
  the 
  fry 
  can 
  be 
  held 
  in 
  tanks 
  until 
  

   they 
  attain 
  a 
  length 
  of 
  an 
  inch 
  before 
  being 
  i)lanted, 
  they 
  would 
  be 
  

  

  F. 
  C. 
  R. 
  1897 
  9 
  

  

  