﻿OCEANOGRAPHY 
  — 
  STETSON 
  235 
  

  

  BOTTOM 
  SAMPLING 
  

  

  In 
  the 
  beginning, 
  as 
  we 
  have 
  seen, 
  sampling 
  was 
  merely 
  an 
  adjunct 
  

   of 
  sounding. 
  A 
  sample 
  was 
  taken 
  merely 
  to 
  inform 
  the 
  navigator, 
  

   by 
  notations 
  placed 
  on 
  the 
  printed 
  chart, 
  over 
  what 
  general 
  type 
  of 
  

   bottom 
  he 
  was 
  sailing. 
  For 
  this 
  purpose 
  a 
  small 
  bit 
  of 
  sediment 
  

   plugged 
  in 
  the 
  sounding 
  tube 
  or 
  a 
  smear 
  stuck 
  to 
  the 
  grease 
  on 
  the 
  

   end 
  of 
  the 
  lead 
  was 
  sufficient. 
  Later, 
  scraper 
  dredges 
  were 
  de- 
  

   veloped 
  by 
  the 
  biologists, 
  and 
  various 
  kinds 
  of 
  scoops 
  and 
  bucket 
  

   dredges, 
  capable 
  of 
  taking 
  measured 
  portions 
  of 
  the 
  bottom, 
  were 
  

   designed 
  for 
  ecological 
  studies. 
  However, 
  these 
  men 
  were 
  mainly 
  

   interested 
  in 
  obtaining 
  samples 
  for 
  the 
  animals 
  which 
  they 
  contained, 
  

   and 
  the 
  sediment 
  itself 
  was 
  broadly 
  classified 
  as 
  sand 
  or 
  mud 
  and 
  

   usually 
  discarded. 
  

  

  The 
  coring 
  tube 
  can 
  be 
  considered 
  as 
  a 
  sampler 
  primarily 
  for 
  

   geological 
  purposes. 
  Until 
  the 
  invention 
  of 
  the 
  Piggot 
  gun, 
  those 
  

   used 
  in 
  anything 
  but 
  the 
  shallowest 
  water 
  were 
  merely 
  weighted 
  

   tubes, 
  which 
  penetrated 
  the 
  bottom 
  by 
  their 
  own 
  kinetic 
  energy. 
  

   They 
  attained 
  varying 
  degrees 
  of 
  success, 
  depending 
  on 
  their 
  weight 
  

   and 
  the 
  speed 
  at 
  which 
  they 
  could 
  be 
  dropped. 
  Some 
  had 
  a 
  thin, 
  

   inner 
  tube 
  of 
  glass 
  or 
  metal 
  which 
  could 
  be 
  slipped 
  out, 
  thus 
  giving 
  

   the 
  core 
  a 
  permanent 
  container. 
  The 
  length 
  of 
  such 
  cores 
  rarely 
  

   exceeded 
  3 
  or 
  4 
  feet, 
  though 
  recently 
  Dr. 
  F. 
  P. 
  Shepard 
  reported 
  taking 
  

   one 
  of 
  11 
  feet. 
  

  

  Coring 
  has 
  played 
  a 
  prominent 
  part 
  in 
  the 
  work 
  of 
  two 
  recent 
  

   expeditions; 
  the 
  Meteor 
  in 
  her 
  traverses 
  across 
  the 
  South 
  Atlantic 
  has 
  

   taken 
  numerous 
  cores 
  with 
  a 
  modified 
  Ekman 
  type 
  of 
  sampler, 
  and 
  

   an 
  important 
  series 
  of 
  papers 
  on 
  the 
  sediments 
  and 
  their 
  faunas 
  by 
  

   Pratje, 
  Correns, 
  and 
  G. 
  and 
  W. 
  Schott 
  has 
  resulted 
  (Meteor 
  Expedi- 
  

   tion, 
  1935-39). 
  Besides 
  showing 
  the 
  areal 
  distribution 
  of 
  the 
  differ- 
  

   ent 
  types 
  of 
  material, 
  the 
  tube 
  penetrated 
  deeper 
  layers 
  in 
  which 
  evi- 
  

   dence 
  of 
  climatic 
  changes 
  are 
  recorded. 
  The 
  Snellius, 
  in 
  the 
  Dutch 
  

   East 
  Indies, 
  also 
  took 
  many 
  cores, 
  particularly 
  in 
  and 
  around 
  the 
  

   deeps 
  and 
  on 
  the 
  slopes 
  of 
  submarine 
  volcanoes. 
  These 
  have 
  been 
  

   discussed 
  by 
  Kuenen 
  (Snellius 
  Expedition, 
  1935) 
  in 
  connection 
  with 
  

   the 
  question 
  of 
  the 
  sliding 
  of 
  sediment 
  down 
  the 
  sides 
  of 
  the 
  deeps 
  as 
  

   a 
  process 
  which 
  might 
  tend 
  eventually 
  to 
  fill 
  up 
  these 
  downwarps, 
  

   and 
  also 
  with 
  regard 
  to 
  the 
  structures 
  which 
  submarine 
  landslides 
  

   might 
  be 
  expected 
  to 
  produce. 
  

  

  The 
  Piggot 
  gun 
  has 
  been 
  fully 
  described 
  by 
  its 
  inventor 
  (Piggot, 
  

   1936), 
  and 
  the 
  details 
  of 
  its 
  construction 
  need 
  not 
  be 
  discussed 
  here. 
  

   Support 
  for 
  the 
  original 
  design 
  and 
  experimentation 
  was 
  furnished 
  by 
  

   a 
  grant 
  from 
  the 
  Penrose 
  Bequest 
  of 
  the 
  Geological 
  Society 
  of 
  Amer- 
  

   ica. 
  The 
  driving 
  force 
  for 
  the 
  tube, 
  or 
  bit, 
  is 
  produced 
  by 
  a 
  powder 
  

   charge, 
  contained 
  in 
  a 
  watertight 
  cartridge, 
  which 
  is 
  detonated 
  when 
  

  

  