﻿248 
  

  

  Prof. 
  W. 
  Thomson 
  on 
  the 
  

  

  [Feb. 
  4, 
  

  

  convenience 
  of 
  reference, 
  the 
  " 
  Melanesian 
  Sea," 
  is 
  that 
  there 
  is 
  no 
  free 
  

   communication 
  between 
  this 
  sea 
  and 
  the 
  outer 
  ocean 
  to 
  a 
  greater 
  depth 
  

   than 
  1300 
  fathoms, 
  the 
  encircling 
  barrier 
  being 
  complete 
  up 
  to 
  that 
  

   point. 
  

  

  The 
  " 
  Melanesian 
  Sea 
  " 
  is 
  in 
  the 
  belt 
  of 
  the 
  S.E. 
  trade-winds, 
  and 
  the 
  

   general 
  course 
  of 
  a 
  drift-current 
  which 
  traverses 
  its 
  long 
  axis, 
  at 
  an 
  

   average 
  rate 
  of 
  half 
  a 
  knot 
  an 
  hour, 
  is 
  to 
  the 
  westward 
  ; 
  evaporation 
  is, 
  

   as 
  it 
  is 
  usually 
  throughout 
  the 
  course 
  of 
  the 
  trade-winds, 
  greatly 
  in 
  

   excess 
  of 
  precipitation, 
  so 
  that 
  a 
  large 
  amount 
  of 
  the 
  surface-water 
  is 
  

   removed. 
  This 
  must, 
  of 
  course, 
  be 
  replaced, 
  and 
  it 
  is 
  so 
  by 
  an 
  indraught 
  

   of 
  ocean-water 
  over 
  the 
  lowest 
  part 
  of 
  the 
  barrier, 
  at 
  the 
  proper 
  tempera- 
  

   ture 
  for 
  that 
  depth. 
  We 
  had 
  previously 
  found 
  a 
  temperature 
  of 
  l° 
  - 
  7 
  C. 
  

   at 
  a 
  depth 
  of 
  1300 
  fathoms 
  on 
  the 
  16th, 
  the 
  19th, 
  and 
  the 
  21st 
  of 
  June 
  

   between 
  Australia 
  and 
  New 
  Zealand, 
  on 
  the 
  17th 
  of 
  July 
  in 
  lat. 
  25° 
  5' 
  

   S., 
  long. 
  172° 
  56' 
  W., 
  and 
  earlier 
  on 
  the 
  10th 
  of 
  March 
  in 
  lat. 
  47° 
  25' 
  S. 
  

   The 
  bottom 
  within 
  the 
  Melanesian 
  Sea 
  may 
  be 
  described 
  generally 
  as 
  

   " 
  red 
  clay," 
  with 
  a 
  small 
  but 
  varying 
  proportion 
  of 
  the 
  shells 
  of 
  Foraniini- 
  

   fera, 
  sometimes 
  whole, 
  but 
  more 
  usually 
  much 
  broken 
  up 
  and 
  decomposed. 
  

   In 
  one 
  or 
  two 
  soundings 
  the 
  tube 
  showed 
  curiously 
  interstratified 
  de- 
  

   posits, 
  differing 
  markedly 
  in 
  colour 
  and 
  in 
  composition. 
  The 
  trawl 
  was 
  

   sent 
  down 
  on 
  the 
  25th 
  of 
  August 
  to 
  a 
  depth 
  of 
  2440 
  fathoms. 
  The 
  

   animals 
  procured 
  were 
  few 
  in 
  number 
  — 
  some 
  spicules 
  of 
  Hyalonema, 
  a 
  

   dead 
  example 
  of 
  Fungia 
  symmetrica, 
  two 
  living 
  specimens 
  of 
  a 
  species 
  of 
  

   Umbellularia 
  (which 
  appears 
  to 
  differ 
  in 
  some 
  respects 
  from 
  the 
  Atlantic 
  

   form), 
  and 
  a 
  very 
  fine 
  and 
  perfect 
  Brisinga, 
  also 
  living. 
  The 
  existence 
  of 
  

   animal 
  life 
  is 
  therefore 
  not 
  impossible 
  in 
  the 
  still 
  bottom-water 
  of 
  such 
  

   an 
  enclosed 
  sea 
  ; 
  but, 
  as 
  we 
  have 
  already 
  seen 
  in 
  the 
  Mediterranean, 
  the 
  

   conditions 
  do 
  not 
  appear 
  to 
  be 
  favourable 
  to 
  its 
  development. 
  On 
  the 
  

   29th 
  of 
  August 
  we 
  trawled 
  in 
  1400 
  fathoms, 
  about 
  75 
  miles 
  to 
  the 
  east 
  

   of 
  Raine 
  Island, 
  with 
  somewhat 
  greater 
  success. 
  This 
  might 
  have 
  been 
  

   anticipated, 
  as 
  the 
  depth 
  was 
  not 
  much 
  greater 
  than 
  that 
  at 
  which 
  the 
  

   free 
  interchange 
  of 
  water 
  was 
  taking 
  place, 
  and 
  diffusion 
  and 
  intermix- 
  

   ture 
  were 
  no 
  doubt 
  much 
  more 
  rapid 
  than 
  at 
  the 
  bottom 
  

  

  On 
  the 
  31st 
  of 
  August 
  we 
  visited 
  Raine 
  Island, 
  which 
  we 
  found 
  to 
  

   correspond 
  in 
  every 
  respect 
  to 
  Jukes's 
  description 
  in 
  the 
  "Voyage 
  of 
  the 
  

   ' 
  Fly.' 
  " 
  "We 
  observed 
  and 
  collected 
  the 
  species 
  of 
  birds 
  which 
  were 
  

   breeding 
  there. 
  In 
  the 
  afternoon 
  we 
  dredged 
  off 
  the 
  island 
  in 
  155 
  

   fathoms, 
  with 
  small 
  success, 
  and 
  proceeded 
  towards 
  Port 
  Albany, 
  Cape 
  

   "York, 
  where 
  we 
  arrived 
  on 
  the 
  1st 
  of 
  September. 
  

  

  "We 
  left 
  Somerset 
  on 
  the 
  8th, 
  and 
  proceeded 
  across 
  the 
  Arafura 
  Sea 
  

   to 
  the 
  Aru 
  Islands, 
  reaching 
  Dobbo. 
  on 
  the 
  island 
  of 
  Wamma, 
  on 
  the 
  16th. 
  

   We 
  found 
  no 
  depth 
  in 
  the 
  Arafura 
  Sea 
  greater 
  than 
  50 
  fathoms, 
  and 
  the 
  

   average 
  depth 
  was 
  from 
  25 
  to 
  30 
  fathoms. 
  The 
  bottom 
  was 
  a 
  greenish 
  

   mud, 
  due 
  apparently 
  to 
  a 
  great 
  degree 
  to 
  the 
  deposit 
  from 
  the 
  great 
  

   rivers 
  of 
  New 
  Guinea 
  and 
  the 
  rivers 
  falling 
  into 
  the 
  Gulf 
  of 
  Carpentaria. 
  

  

  