﻿478 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  the 
  bath 
  tanks 
  with 
  dip 
  nets 
  made 
  of 
  wire 
  or 
  iron 
  links. 
  In 
  canneries 
  

   not 
  having 
  engines 
  the 
  tanks 
  are 
  heated 
  by 
  a 
  furnace. 
  When 
  the 
  cans 
  

   reach 
  the 
  testing-room 
  they 
  are 
  carefully 
  examined 
  or 
  "tested." 
  The 
  

   covers 
  of 
  the 
  cans 
  are 
  always 
  concaved, 
  so 
  that 
  when 
  they 
  are 
  put 
  on 
  

   the 
  air 
  is 
  excluded; 
  but 
  it 
  often 
  happens 
  that 
  the 
  soldering 
  is 
  not 
  done 
  

   perfectly, 
  and 
  as 
  a 
  consequence 
  the 
  oil 
  leaks 
  out, 
  the 
  vacuum 
  becomes 
  

   filled 
  with 
  air, 
  which 
  expands 
  in 
  the 
  heat 
  of 
  the 
  bath 
  and 
  causes 
  the 
  

   cover 
  of 
  the 
  can 
  to 
  present 
  a 
  bulged 
  a])pearance. 
  These 
  are 
  called 
  

   "swelled 
  heads," 
  and 
  are 
  easily 
  detected 
  by 
  the 
  testers. 
  

  

  An 
  appliance 
  has 
  recently 
  been 
  devised 
  and 
  used 
  by 
  Messrs. 
  George 
  

   O. 
  Grady 
  & 
  Co., 
  of 
  Eastport, 
  for 
  testing 
  the 
  cans 
  before 
  they 
  are 
  filled. 
  

   It 
  consists 
  of 
  a 
  cylindrical 
  tank 
  about 
  5 
  feet 
  in 
  length 
  and 
  1 
  foot 
  in 
  

   diameter, 
  fixed 
  in 
  an 
  upright 
  position 
  at 
  the 
  end 
  of 
  a 
  table. 
  The 
  tank 
  

   is 
  filled 
  with 
  water 
  to 
  within 
  about 
  18 
  inches 
  of 
  the 
  top 
  by 
  means 
  of 
  a 
  

   pipe 
  leading 
  from 
  the 
  boiler 
  of 
  the 
  engine. 
  Air 
  is 
  forced 
  through 
  

   another 
  pipe 
  into 
  the 
  space 
  above 
  the 
  water 
  by 
  the 
  air-pump 
  which 
  

   supplies 
  air 
  for 
  oxygenizing 
  the 
  flame 
  of 
  the 
  kerosene 
  oil 
  stoves 
  used 
  

   in 
  soldering. 
  The 
  pressure 
  of 
  air, 
  which 
  requires 
  to 
  be 
  about 
  12 
  pounds, 
  

   and 
  the 
  quantity 
  of 
  water 
  are 
  regulated 
  by 
  steam 
  and 
  water 
  gauges. 
  

   On 
  the 
  table, 
  a 
  few 
  feet 
  from 
  the 
  tank, 
  is 
  a 
  tin 
  pan 
  or 
  tray, 
  in 
  the 
  center 
  

   of 
  which 
  is 
  a 
  rubber 
  pad 
  a 
  little 
  larger 
  than 
  a 
  sardine 
  can. 
  A 
  pipe 
  

   fitted 
  with 
  a 
  valve 
  leads 
  from 
  the 
  tank 
  and 
  passes 
  up 
  through 
  the 
  pad 
  

   from 
  the 
  under 
  side 
  of 
  the 
  table. 
  The 
  can 
  when 
  tested 
  is 
  placed 
  bottom 
  

   upward 
  over 
  the 
  nozzle 
  of 
  the 
  pipe 
  and 
  held 
  in 
  position 
  by 
  pressure 
  

   applied 
  with 
  a 
  lever 
  worked 
  by 
  the 
  foot. 
  The 
  operator 
  then 
  turns 
  a 
  

   thumb-piece 
  on 
  the 
  pipe, 
  which 
  opens 
  the 
  valve 
  and 
  lets 
  a 
  small 
  stream 
  

   of 
  water 
  into 
  the 
  inverted 
  can. 
  If 
  it 
  is 
  not 
  perfectly 
  tight 
  the 
  leak 
  is 
  

   immediately 
  disclosed 
  by 
  the 
  fine 
  jet 
  of 
  water 
  which 
  passes 
  through 
  

   it. 
  The 
  water, 
  arfter 
  being 
  used, 
  escapes 
  by 
  a 
  waste-pipe 
  in 
  the 
  tray. 
  

   One 
  advantage 
  of 
  this 
  method 
  is 
  that 
  it 
  shows 
  which 
  class 
  of 
  solderers 
  

   has 
  done 
  the 
  poor 
  work, 
  whether 
  the 
  seamers 
  or 
  can-makers, 
  and 
  the 
  

   defective 
  cans 
  are 
  returned 
  to 
  them 
  for 
  the 
  leaks 
  to 
  be 
  mended, 
  after 
  

   which 
  they 
  are 
  again 
  tested 
  in 
  a 
  similar 
  manner. 
  If 
  any 
  cans 
  are 
  

   imperfect 
  after 
  coming 
  from 
  the 
  bath 
  the 
  fault 
  is 
  known 
  to 
  lie 
  with 
  the 
  

   sealers. 
  An 
  improvement 
  is 
  contemplated 
  by 
  arranging 
  the 
  valve 
  to 
  

   open 
  with 
  the 
  lever 
  when 
  the 
  pressure 
  is 
  applied, 
  and 
  thus 
  avoid 
  the 
  

   movement 
  of 
  the 
  hand 
  in 
  turning 
  the 
  thumb 
  piece. 
  The 
  apparatus 
  

   costs 
  about 
  $15, 
  and 
  is 
  operated 
  by 
  one 
  person. 
  

  

  The 
  cans 
  which 
  are 
  discovered 
  to 
  be 
  defective 
  after 
  coming 
  from 
  the 
  

   bath 
  are 
  culled 
  out 
  and 
  turned 
  over 
  to 
  the 
  leak-menders. 
  The 
  leaks 
  

   not 
  only 
  have 
  to 
  be 
  mended, 
  but 
  the 
  air 
  allowed 
  to 
  escape 
  and 
  the 
  can 
  

   refilled 
  with 
  oil. 
  A 
  puncture 
  is 
  made 
  usually 
  on 
  the 
  bottom 
  of 
  the 
  can 
  

   at 
  one 
  end 
  near 
  the 
  edge. 
  The 
  cover 
  and 
  bottom 
  are 
  then 
  pressed 
  back 
  

   into 
  their 
  proper 
  concave 
  shape 
  and 
  another 
  puncture 
  is 
  made 
  in 
  a 
  

   similar 
  place 
  at 
  the 
  opposite 
  end, 
  after 
  which 
  the 
  can 
  is 
  stood 
  endwise 
  

   in 
  a 
  pan 
  of 
  oil 
  until 
  it 
  is 
  refilled. 
  The 
  punctures 
  are 
  then 
  closed 
  with 
  

   solder, 
  and 
  the 
  can 
  is 
  again 
  put 
  through 
  the 
  bath. 
  The 
  perfect 
  cans, 
  

  

  