﻿REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  87 
  

  

  pi}'; 
  it 
  grows 
  more 
  rapidlj^ 
  than 
  when 
  at 
  the 
  bottom; 
  it 
  is 
  more 
  regu- 
  

   lar, 
  and 
  there 
  is 
  no 
  "root," 
  the 
  portion 
  of 
  the 
  sponge 
  which 
  in 
  service 
  

   proves 
  itself 
  least 
  durable. 
  

  

  As 
  stated 
  in 
  the 
  report 
  for 
  the 
  preceding 
  fiscal 
  year, 
  the 
  cuttings 
  

   are 
  in 
  general 
  subcubical 
  in 
  shape 
  and 
  about 
  2 
  cubic 
  inches 
  in 
  volume. 
  

   They 
  are 
  cut 
  from 
  the 
  live 
  sponges 
  with 
  a 
  sharp 
  knife, 
  and 
  each 
  has 
  

   at 
  least 
  one 
  face 
  covered 
  by 
  the 
  original 
  skin. 
  A 
  slit 
  about 
  1 
  inch 
  in 
  

   depth 
  is 
  made 
  parallel 
  to 
  the 
  longest 
  axis 
  and 
  placed 
  astride 
  the 
  sus- 
  

   pension 
  wire. 
  A 
  piece 
  of 
  aluminum 
  wire 
  about 
  4 
  inches 
  in 
  length 
  is 
  

   thrust 
  through 
  the 
  two 
  flaps 
  and 
  the 
  ends 
  twisted 
  around 
  the 
  suspen- 
  

   sion 
  wire 
  in 
  such 
  manner 
  as 
  to 
  close 
  the 
  slit. 
  Within 
  a 
  week 
  the 
  

   opposed 
  faces 
  of 
  the 
  slit 
  unite 
  and 
  the 
  cutting 
  heals 
  around 
  the 
  sus- 
  

   pension 
  wire. 
  

  

  The 
  general 
  system 
  already 
  evolved 
  is 
  believed 
  to 
  be 
  that 
  which 
  will 
  

   ultimately 
  obtain 
  in 
  practice, 
  but 
  the 
  ideal 
  material 
  for 
  the 
  suspension 
  

   lines 
  has 
  not 
  yet 
  been 
  found. 
  Copper 
  wires 
  with 
  okonite 
  and 
  under- 
  

   writer's 
  insulations, 
  asbestos 
  cord, 
  thin 
  manila 
  and 
  cotton 
  rope, 
  and 
  

   stranded 
  galvanized 
  iron 
  wire 
  were 
  the 
  materials 
  first 
  employed. 
  The 
  

   ropes 
  quickly 
  rot, 
  and 
  within 
  a 
  year 
  the 
  okonite 
  insulation 
  softens 
  

   and 
  breaks 
  from 
  the 
  wire, 
  so 
  that 
  the 
  exposed 
  copper 
  is 
  acted 
  upon 
  by 
  

   the 
  sea 
  water 
  and 
  weakens 
  to 
  the 
  breaking 
  point. 
  Underwriter's 
  

   wire, 
  a 
  much 
  cheaper 
  insulation 
  and 
  inferior 
  for 
  electrical 
  purposes, 
  

   lasts 
  much 
  longer, 
  but 
  at 
  the 
  end 
  of 
  the 
  fiscal 
  year 
  lines 
  which 
  had 
  

   been 
  in 
  use 
  eighteen 
  months 
  were 
  beginning 
  to 
  lose 
  their 
  insulation 
  

   in 
  places, 
  A 
  heavier 
  wire 
  and 
  thicker 
  covering 
  than 
  that 
  already 
  

   employed 
  would 
  doubtless 
  be 
  more 
  durable. 
  Asbestos 
  cord, 
  which 
  is 
  

   about 
  twice 
  as 
  costl}^ 
  as 
  the 
  underwriter's 
  wire, 
  is 
  slightly, 
  if 
  at 
  all, 
  

   acted 
  upon 
  chemicall}^ 
  by 
  the 
  sea 
  water, 
  but 
  when 
  wet 
  the 
  fibers 
  

   become 
  slippery 
  and 
  the 
  tensile 
  strength 
  of 
  the 
  cord 
  is 
  much 
  reduced. 
  

   When 
  the 
  sponges 
  are 
  large 
  the 
  strain 
  on 
  the 
  line 
  becomes 
  con- 
  

   siderable, 
  especially 
  during 
  storms, 
  and 
  it 
  is 
  doubtful 
  whether 
  plain 
  

   asbestos 
  cord 
  will 
  prove 
  sufiiciently 
  strong. 
  Experiments 
  now 
  under 
  

   way 
  indicate, 
  however, 
  that 
  by 
  suitable 
  treatment 
  the 
  strength 
  of 
  the 
  wet 
  

   cord 
  may 
  be 
  more 
  than 
  doubled 
  without 
  materially 
  increasing 
  the 
  cost. 
  

  

  The 
  organic 
  attachment 
  of 
  the 
  cuttings 
  to 
  the 
  suspension 
  wire 
  is 
  

   advantageous, 
  but 
  not 
  essential. 
  The 
  condition 
  has 
  been 
  attained 
  

   with 
  none 
  of 
  the 
  materials 
  above 
  enumerated, 
  and 
  during 
  the 
  present 
  

   year 
  experiments 
  have 
  been 
  conducted 
  with 
  the 
  accomplishment 
  of 
  

   this 
  end 
  in 
  view. 
  Lead 
  has 
  proved 
  to 
  be 
  the 
  most 
  satisfactory^ 
  mate- 
  

   rial, 
  as 
  it 
  is 
  but 
  little 
  affected 
  by 
  sea 
  salts 
  and 
  the 
  cuttings 
  soon 
  

   become 
  fixed. 
  Lead 
  wire 
  is 
  useless 
  on 
  account 
  of 
  its 
  lack 
  of 
  tensile 
  

   strength. 
  Lead-covered 
  insulated 
  copper 
  wire 
  is 
  too 
  heavy, 
  or, 
  if 
  

   made 
  sufiiciently 
  light, 
  the 
  lead 
  casing 
  is 
  so 
  thin 
  that 
  it 
  breaks, 
  cuts 
  

   the 
  insulation, 
  and, 
  cdming 
  into 
  contact 
  with 
  the 
  copper, 
  establishes 
  a 
  

   destructive 
  electrolytic 
  action. 
  To 
  overcome 
  these 
  several 
  difficulties, 
  

  

  