﻿190 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  be 
  taken 
  to 
  establish 
  the 
  approximate 
  velocity 
  and 
  the 
  general 
  set 
  of 
  

   ebb 
  and 
  flood 
  tides, 
  as 
  such 
  data 
  is 
  essential 
  in 
  connection 
  with 
  the 
  

   food 
  supply 
  of 
  the 
  oyster 
  and 
  the 
  amount 
  of 
  silt 
  or 
  mud 
  deposited 
  on 
  

   the 
  l>eds. 
  

  

  As 
  the 
  spawning 
  habits 
  of 
  the 
  oyster 
  depend 
  to 
  a 
  great 
  extent 
  on 
  

   the 
  temperature 
  of 
  the 
  water, 
  tlie 
  temperature 
  observations 
  were 
  im- 
  

   portant. 
  Information 
  in 
  regard 
  to 
  the 
  spawning 
  was 
  to 
  be 
  collected 
  

   from 
  local 
  sources 
  and 
  from 
  a 
  study 
  of 
  the 
  specimens 
  preserved. 
  

  

  The 
  lirst 
  matter 
  of 
  consideration 
  was 
  tbe 
  location 
  and 
  establishment 
  

   of 
  the 
  tide 
  gauge. 
  A 
  position 
  was 
  chosen 
  for 
  the 
  main 
  gauge, 
  which 
  

   was 
  centrally 
  located 
  with 
  regard 
  to 
  the 
  whole 
  area 
  to 
  be 
  covered, 
  and 
  

   at 
  the 
  same 
  time 
  in 
  a 
  location 
  where 
  the 
  tides 
  would 
  be 
  nornml 
  as 
  far 
  

   as 
  possible, 
  and 
  where 
  the 
  density 
  and 
  temperature 
  observations 
  would 
  

   give 
  good 
  average 
  results 
  for 
  a 
  large 
  area. 
  The 
  gauge 
  was 
  established 
  

   on 
  the 
  north 
  side 
  of 
  Ai^alachicola 
  Bay, 
  between 
  Green 
  Point 
  and 
  Apa- 
  

   lachicola. 
  Auxiliary 
  gauges 
  were 
  used 
  and 
  compared 
  with 
  tbe 
  main 
  

   gauge 
  whenever 
  a 
  difference 
  of 
  level 
  or 
  difference 
  in 
  the 
  time 
  of 
  high 
  

   or 
  low 
  water 
  existed. 
  At 
  the 
  end 
  of 
  the 
  season 
  several 
  different 
  bench 
  

   marks 
  were 
  established, 
  that 
  the 
  result 
  of 
  the 
  long 
  series 
  of 
  observations 
  

   might 
  be 
  useful 
  in 
  the 
  future. 
  

  

  Density, 
  temperature, 
  and 
  current 
  observations, 
  as 
  well 
  as 
  all 
  the 
  

   usual 
  observations 
  required 
  by 
  log, 
  were 
  taken 
  at 
  the 
  ship 
  regularly, 
  as 
  

   well 
  as 
  at 
  the 
  main 
  gauge, 
  so 
  that 
  at 
  many 
  localities 
  a 
  long 
  series 
  of 
  

   observations 
  were 
  obtained. 
  

  

  The 
  triangulation 
  points 
  given 
  were 
  those 
  determined 
  and 
  marked 
  

   at 
  the 
  time 
  of 
  the 
  original 
  survey 
  in 
  1858. 
  As 
  may 
  be 
  supposed, 
  many 
  

   could 
  not 
  be 
  recovered, 
  and 
  in 
  some 
  cases 
  their 
  sites 
  had 
  been 
  washed 
  

   away 
  by 
  the 
  encroachment 
  of 
  the 
  sea. 
  In 
  Aj)alachicola 
  Bay 
  and 
  St. 
  

   George 
  Sound 
  so 
  few 
  were 
  recovered 
  that 
  it 
  was 
  necessary 
  to 
  trian- 
  

   gulate 
  a 
  considerable 
  area, 
  by 
  use 
  of 
  the 
  theodolite, 
  in 
  order 
  to 
  establish 
  

   the 
  signals. 
  In 
  St. 
  Vincent 
  Sound, 
  owing 
  to 
  its 
  remote 
  position, 
  nearly 
  

   all 
  the 
  triangulation 
  points 
  were 
  recovered. 
  Signals 
  were 
  built 
  on 
  the 
  

   triangulation 
  points 
  when 
  recovered, 
  and 
  other 
  signals 
  built 
  and 
  located 
  

   along 
  the 
  shore 
  and 
  on 
  the 
  reefs 
  of 
  the 
  sounds. 
  

  

  The 
  waters 
  of 
  Apalachicola 
  Bay 
  and 
  the 
  adjacent 
  waters 
  are 
  very 
  

   shoal, 
  and 
  a 
  good 
  deal 
  of 
  time 
  was 
  lost 
  on 
  that 
  account, 
  as 
  the 
  Fish 
  

   Hawk, 
  drawing 
  8 
  feet, 
  could 
  only 
  navigate 
  in 
  certain 
  channels, 
  and 
  

   then 
  only, 
  in 
  some 
  cases, 
  at 
  high 
  water. 
  St. 
  Vincent 
  Sound 
  could 
  not 
  

   be 
  reached 
  from 
  the 
  eastward, 
  on 
  account 
  of 
  shoal 
  water, 
  and 
  the 
  scene 
  

   of 
  work 
  was 
  too 
  far 
  off 
  to 
  send 
  the 
  boats. 
  Therefore, 
  an 
  attempt 
  was 
  ' 
  

   made 
  to 
  get 
  the 
  ship 
  into 
  Indian 
  Pass, 
  which 
  proved 
  successful 
  after 
  

   lirst 
  surveying 
  and 
  buoying 
  the 
  channel. 
  The 
  channel 
  was 
  very 
  nar- 
  

   row, 
  but 
  deeper 
  water 
  was 
  found 
  than 
  was 
  shown 
  on 
  the 
  Coast 
  Survey 
  

   chart. 
  An 
  inspection 
  of 
  the 
  chart 
  accomi)anying 
  this 
  report 
  will 
  show 
  

   a 
  few 
  other 
  channels 
  surveyed 
  that 
  were 
  apparently 
  not 
  necessary 
  to 
  

   the 
  work, 
  as, 
  for 
  example, 
  the 
  cut 
  across 
  Cat 
  Point 
  Shoal 
  and 
  the 
  cut 
  

   and 
  channel 
  to 
  A])alachicolii, 
  but 
  in 
  every 
  such 
  case 
  these 
  surveys 
  were 
  

   made 
  for 
  convenience 
  in 
  navigating 
  the 
  ship. 
  

  

  