﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  165 
  

  

  imity 
  of 
  the 
  machine 
  shops 
  and 
  scientific 
  laboratory 
  of 
  the 
  Woods 
  

   Hole 
  station, 
  the 
  cost 
  of 
  construction 
  and 
  maintenance 
  would 
  be 
  less 
  

   than 
  elsewhere. 
  (2) 
  The 
  physical 
  conditions 
  were 
  better 
  understood 
  

   there 
  than 
  elsewhere. 
  (3) 
  It 
  seemed 
  probable 
  that 
  the 
  temperature 
  

   conditions 
  would 
  more 
  nearly 
  approach 
  those 
  at 
  Wickford 
  than 
  would 
  

   be 
  the 
  case 
  farther 
  north. 
  (4) 
  It 
  was 
  desirable 
  to 
  compare 
  the 
  results 
  

   of 
  these 
  experiments 
  directl}' 
  with 
  results 
  obtained 
  in 
  earlier 
  experi- 
  

   ments. 
  (5) 
  It 
  seemed 
  desirable 
  to 
  test 
  what 
  several 
  investigators 
  had 
  

   frequently 
  claimed, 
  and 
  what 
  our 
  previous 
  experiments 
  seemed 
  to 
  

   indicate, 
  namely, 
  that 
  the 
  biological 
  conditions 
  at 
  Woods 
  Hole 
  were 
  

   extremely 
  unfavorable 
  for 
  the 
  development 
  of 
  young 
  lobsters. 
  

  

  The 
  investigations 
  of 
  1902 
  were 
  placed 
  in 
  charge 
  of 
  the 
  writer, 
  who 
  

   began 
  the 
  work 
  of 
  constructing 
  apparatus 
  the 
  last 
  week 
  of 
  April. 
  

  

  THE 
  APPARATUS. 
  

  

  In 
  order 
  that 
  the 
  comparison 
  of 
  results 
  might 
  be 
  more 
  satisfactory, 
  

   it 
  was 
  decided 
  to 
  emplo}^ 
  essentially 
  the 
  same 
  stirring 
  mechanism 
  and 
  

   bags 
  as 
  were 
  used 
  at 
  Wickford 
  in 
  1901. 
  

  

  The 
  plant 
  consisted 
  of 
  a 
  strong 
  raft 
  or 
  float 
  supporting 
  60 
  cylin- 
  

   drical 
  scrim 
  bags, 
  in 
  which 
  were 
  suspended 
  two-bladed 
  propellers, 
  as 
  

   at 
  Wickford, 
  and 
  these 
  were 
  rotated 
  by 
  a 
  small 
  gasoline 
  engine. 
  On 
  the 
  

   stern 
  of 
  the 
  raft 
  was 
  built 
  a 
  small 
  house 
  which 
  protected 
  the 
  engine 
  

   and 
  served 
  as 
  a 
  laboratory 
  and 
  shelter 
  for 
  the 
  attendants. 
  

  

  The 
  construction 
  of 
  the 
  bag 
  and 
  the 
  propellers 
  was 
  the 
  same 
  as 
  in 
  

   the 
  Wickford 
  experiments. 
  The 
  raft 
  was 
  made 
  by 
  fastening 
  together 
  

   two 
  ^pars 
  50 
  feet 
  long 
  and 
  2 
  feet 
  in 
  diameter, 
  with 
  four 
  6 
  by 
  6 
  tim- 
  

   bers 
  25 
  feet 
  long. 
  To 
  give 
  added 
  strength 
  and 
  buoyancy, 
  a 
  third 
  spar 
  

   was 
  securel}' 
  bolted 
  between 
  and 
  parallel 
  to 
  the 
  others, 
  but 
  a 
  little 
  to 
  

   one 
  side 
  of 
  the 
  center 
  of 
  the 
  raft. 
  

  

  Thus 
  the 
  three 
  spars, 
  the 
  platform, 
  and 
  the 
  forward 
  timber 
  inclosed 
  

   two 
  "wells" 
  of 
  unecjual 
  size, 
  one 
  40 
  feet 
  by 
  7i 
  feet, 
  the 
  other 
  40 
  feet 
  

   by 
  111^ 
  feet. 
  These 
  wells 
  were 
  cut 
  up 
  into 
  a 
  number 
  of 
  smaller 
  ones 
  

   by 
  planks 
  placed 
  across 
  the 
  spars 
  at 
  intervals 
  of 
  3i 
  feet. 
  To 
  the 
  under 
  

   side 
  of 
  these 
  planks 
  were 
  nailed 
  two 
  posts 
  of 
  2 
  by 
  3 
  stock 
  4 
  feet 
  in 
  

   length, 
  and 
  a 
  third 
  piece 
  of 
  2 
  b}^ 
  3 
  as 
  long 
  as 
  the 
  width 
  of 
  the 
  "well," 
  

   connected 
  the 
  lower 
  ends 
  of 
  the 
  posts. 
  The 
  planks 
  and 
  posts 
  were 
  

   securely 
  spiked 
  to 
  the 
  spars 
  and 
  formed 
  a 
  firm 
  and 
  rigid 
  support 
  for 
  

   the 
  bag. 
  There 
  was 
  space 
  for 
  60 
  bags, 
  or 
  five 
  times 
  as 
  many 
  as 
  had 
  

   been 
  used 
  at 
  Wickford. 
  Across 
  the 
  stern 
  of 
  the 
  raft 
  was 
  built 
  a 
  plank 
  

   platform 
  25 
  by 
  10 
  feet, 
  which 
  served 
  for 
  support 
  of 
  the 
  engines 
  and 
  

   the 
  house. 
  

  

  The 
  power 
  for 
  rotating 
  the 
  fans 
  was 
  furnished 
  by 
  a 
  Fairbanks 
  & 
  

   Morse 
  2i-horsepower 
  gasoline 
  engine, 
  as 
  at 
  Wickford, 
  and 
  was 
  trans- 
  

   mitted 
  to 
  the 
  main 
  shaft, 
  which 
  ran 
  the 
  length 
  of 
  the 
  middle 
  spar 
  of 
  

   the 
  raft, 
  by 
  a 
  system 
  of 
  gears 
  which 
  reduced 
  the 
  speed 
  to 
  the 
  required 
  

  

  