﻿MANUAL 
  OF 
  FISH-CULTURE. 
  109 
  

  

  THE 
  HATCHERY. 
  

  

  The 
  liatcliing'-trough 
  or 
  tank 
  iu 
  use 
  at 
  Nortliville 
  eoinbiiiea 
  tlie 
  prin- 
  

   ciples 
  of 
  botli 
  the 
  Clark 
  aud 
  the 
  Williamson 
  hatching- 
  apparatus 
  and 
  

   is 
  therefore 
  called 
  the 
  Clark- 
  Williamson 
  hatching-box. 
  It 
  possesses 
  

   more 
  advantages 
  than 
  any 
  other 
  in 
  use 
  for 
  the 
  development 
  of 
  a 
  large 
  

   number 
  of 
  eggs; 
  a 
  thorough 
  circulation 
  is 
  obtained 
  for 
  thousands, 
  the 
  

   apparatus 
  is 
  simple, 
  and 
  the 
  eggs 
  may 
  be 
  readily 
  handled 
  for 
  picking, 
  

   cleaning, 
  etc. 
  It 
  consists 
  of 
  a 
  trough 
  of 
  any 
  length 
  according 
  to 
  the 
  

   number 
  of 
  fry 
  to 
  be 
  held, 
  18^ 
  inches 
  wide 
  inside 
  and 
  1 
  foot 
  deep, 
  with 
  

   partitions 
  to 
  divide 
  it 
  into 
  compartments, 
  and 
  is 
  constructed 
  as 
  follows: 
  

   Only 
  the 
  best 
  li-inch 
  pine 
  is 
  used, 
  all 
  planks 
  containing 
  knots, 
  heavy 
  

   pitch, 
  etc., 
  being 
  rejected, 
  aud 
  the 
  sides 
  and 
  ends 
  are 
  each 
  made 
  of 
  but 
  

   one 
  piece 
  of 
  lumber. 
  The 
  bottom 
  is 
  made 
  first, 
  the 
  strips 
  of 
  diifereut 
  

   widths 
  plowed 
  and 
  tongued 
  securely, 
  and 
  all 
  joints 
  laid 
  in 
  white 
  lead. 
  

  

  Eeferriug 
  to 
  figs. 
  1 
  and 
  3, 
  page 
  110, 
  three-quarters 
  of 
  an 
  inch 
  down 
  

   from 
  the 
  top 
  of 
  the 
  sides 
  is 
  a 
  |-inch 
  groove 
  (A) 
  running 
  the 
  entire 
  length 
  

   of 
  the 
  trough. 
  The 
  partitions, 
  dividing 
  the 
  trough 
  into 
  compartments, 
  

   18f 
  inches 
  by 
  9f 
  iucnes 
  by 
  12 
  inches, 
  are 
  mortised 
  ^ 
  inch 
  iu 
  the 
  sides; 
  

   the 
  first 
  and 
  each 
  alternate 
  partition 
  (B) 
  is 
  fixed 
  ^ 
  inch 
  from 
  the 
  bottom 
  

   of 
  the 
  trough 
  to 
  nllow 
  the 
  water 
  to 
  pass 
  under 
  it; 
  the 
  setiond 
  and 
  each 
  

   alternate 
  partition 
  (C) 
  is 
  mortised 
  into 
  the 
  bottom, 
  and 
  at 
  the 
  top 
  is 
  cut 
  

   out 
  so 
  as 
  to 
  leave 
  a 
  space 
  llf 
  inches 
  long 
  by 
  li 
  inches 
  deep 
  for 
  the 
  

   water 
  to 
  pass 
  over. 
  In 
  the 
  bottom 
  of 
  the 
  boxes 
  thus 
  formed 
  a 
  ^ 
  inch 
  

   strip 
  (D) 
  1^ 
  inch 
  wide 
  is 
  nailed 
  to 
  the 
  sides; 
  upon 
  these 
  the 
  bottom 
  trays 
  

   rest. 
  A 
  crossbar 
  (E), 
  with 
  g-inch 
  block 
  (F) 
  to 
  hold 
  the 
  trays 
  securely 
  

   in 
  place 
  and 
  prevent 
  them 
  from 
  rising 
  in 
  the 
  water, 
  is 
  made 
  to 
  fit 
  in 
  the 
  

   grooves 
  at 
  the 
  sides 
  of 
  the 
  trough. 
  

  

  The 
  capacity 
  of 
  the 
  troughs 
  may 
  be 
  doubled 
  by 
  the 
  addition 
  of 
  a 
  

   second 
  row 
  of 
  boxes, 
  one 
  side 
  of 
  the 
  first 
  tank 
  acting 
  as 
  a 
  partition 
  

   between 
  the 
  two 
  rows. 
  Each 
  box 
  holds 
  eleven 
  trays 
  (G). 
  Ten 
  of 
  these 
  

   are 
  filled 
  with 
  eggs, 
  the 
  eleventh, 
  or 
  top 
  one, 
  acting 
  merely 
  as 
  a 
  cover 
  

   to 
  prevent 
  the 
  eggs 
  on 
  the 
  tenth 
  tray 
  from 
  being 
  carried 
  off 
  by 
  the 
  

   current. 
  The 
  trays 
  are 
  made 
  of 
  ^-inch 
  mesh 
  galvanized 
  wire 
  cloth, 
  

   tacked 
  upon 
  frames 
  16 
  inches 
  long, 
  7 
  inches 
  wide, 
  and 
  ^ 
  inch 
  thick. 
  

   Both 
  the 
  trays 
  and 
  tanks 
  are 
  given 
  three 
  coats 
  of 
  asi^haltum 
  paint 
  

   before 
  being 
  used, 
  and 
  one 
  coat 
  at 
  the 
  beginning 
  of 
  each 
  succeeding 
  

   season. 
  Eleven 
  of 
  such 
  trays, 
  in 
  the 
  box 
  described, 
  will 
  fill 
  the 
  com- 
  

   partment 
  to 
  within 
  § 
  inch 
  of 
  the 
  groove 
  in 
  the 
  sides 
  of 
  the 
  tank; 
  then 
  

   the 
  crossbar 
  with 
  the 
  §-inch 
  feet 
  holds 
  them 
  securely 
  in 
  place. 
  The 
  

   tanks 
  are 
  set 
  upon 
  iron 
  standards 
  cemented 
  in 
  the 
  floor, 
  and 
  are 
  given 
  

   a 
  pitch 
  of 
  I 
  of 
  an 
  inch 
  to 
  the 
  foot. 
  The 
  height 
  of 
  the 
  tauk 
  from 
  the 
  

   floor 
  is 
  a 
  matter 
  of 
  convenience 
  to 
  the 
  operator, 
  depending 
  on 
  the 
  fall 
  

   of 
  water 
  available. 
  • 
  

  

  The 
  water 
  enters 
  through 
  a 
  1-inch 
  pipe 
  at 
  the 
  head 
  of 
  the 
  tank, 
  flow- 
  

   ing 
  down 
  through 
  the 
  first 
  division, 
  up 
  through 
  the 
  second, 
  and 
  so 
  on 
  

   to 
  the 
  lower 
  end. 
  Where 
  water 
  is 
  scarce, 
  two 
  troughs 
  maybe 
  made 
  to 
  

  

  