﻿THE 
  GULF 
  STEEAM 
  MARMER 
  293 
  

  

  namely, 
  by 
  comparison 
  with 
  other 
  bodies 
  of 
  water 
  in 
  the 
  same 
  latitude, 
  

   for 
  example, 
  with 
  the 
  Sargasso 
  Sea. 
  The 
  surface 
  waters 
  of 
  the 
  Gulf 
  

   Stream 
  in 
  the 
  Straits 
  of 
  Florida 
  have 
  about 
  the 
  same 
  temperature 
  as 
  

   the 
  surface 
  waters 
  of 
  the 
  Sargasso 
  Sea. 
  But 
  within 
  the 
  depths 
  the 
  

   Sargasso 
  Sea 
  is 
  much 
  warmer. 
  At 
  a 
  depth 
  of 
  200 
  fathoms 
  the 
  tem- 
  

   perature 
  of 
  thelatter 
  is 
  between 
  60° 
  and 
  65°,^^ 
  while 
  in 
  the 
  Gulf 
  Stream 
  

   at 
  that 
  depth 
  the 
  temperature, 
  as 
  shown 
  by 
  Figure 
  4, 
  averages 
  

   about 
  55°. 
  

  

  With 
  regard 
  to 
  other 
  characteristics 
  there 
  is 
  a 
  like 
  tendency 
  to 
  

   overrate 
  the 
  waters 
  of 
  the 
  Gulf 
  Stream. 
  Highly 
  saline 
  these 
  waters 
  

   are, 
  but 
  not 
  exceptionally 
  so. 
  On 
  the 
  customary 
  salinity 
  scale, 
  in 
  

   which 
  each 
  unit 
  represents 
  one 
  part 
  of 
  salt 
  in 
  a 
  thousand 
  parts 
  of 
  

   water, 
  the 
  surface 
  waters 
  within 
  the 
  straits 
  have 
  a 
  salinity 
  of 
  about 
  

   36. 
  Below 
  the 
  surface 
  the 
  salinity 
  increases 
  gradually 
  until 
  a 
  maxi- 
  

   mum 
  of 
  36/2 
  is 
  reached 
  at 
  a 
  depth 
  of 
  about 
  100 
  fathoms, 
  after 
  which 
  

   the 
  salinity 
  decreases 
  to 
  about 
  35 
  at 
  300 
  fathoms, 
  which 
  salinity 
  

   is 
  then 
  maintained 
  to 
  the 
  bottom. 
  In 
  round 
  numbers 
  we 
  may 
  take 
  the 
  

   salinity 
  of 
  the 
  waters 
  within 
  the 
  straits 
  as 
  a 
  whole 
  to 
  be 
  36. 
  Compared 
  

   to 
  the 
  average 
  salinity 
  of 
  34%, 
  which 
  is 
  accepted 
  as 
  the 
  figure 
  for 
  the 
  

   sea 
  as 
  a 
  whole, 
  the 
  water 
  within 
  the 
  straits 
  is 
  highly 
  saline; 
  but 
  

   toward 
  its 
  eastern 
  end 
  the 
  Sargasso 
  Sea 
  is 
  more 
  saline, 
  having 
  a 
  

   salinity 
  of 
  37/2 
  on 
  the 
  surface 
  and 
  of 
  about 
  36 
  at 
  a 
  depth 
  of 
  300 
  

   fathoms. 
  In 
  depth 
  of 
  color 
  and 
  transparency, 
  the 
  waters 
  in 
  the 
  

   Sargasso 
  Sea 
  likewise 
  exceed 
  those 
  of 
  the 
  Gulf 
  Stream. 
  

  

  In 
  general, 
  however, 
  the 
  Gulf 
  Stream 
  as 
  it 
  issues 
  into 
  the 
  sea 
  

   through 
  the 
  Straits 
  of 
  Florida 
  may 
  be 
  characterized 
  as 
  a 
  swift, 
  highly 
  

   saline 
  current 
  of 
  blue 
  water 
  whose 
  upper 
  stratum 
  is 
  composed 
  of 
  

   warm 
  water. 
  

  

  UNION 
  WITH 
  THE 
  ANTILLES 
  CURRENT 
  

  

  On 
  issuing 
  into 
  the 
  sea 
  north 
  of 
  Little 
  Bahama 
  Bank 
  the 
  Gulf 
  

   Stream 
  loses 
  the 
  relatively 
  great 
  velocity 
  which 
  characterized 
  it 
  

   within 
  the 
  straits. 
  From 
  3}/2 
  knots 
  along 
  the 
  axis 
  within 
  the 
  narrows 
  

   of 
  the 
  straits, 
  there 
  is 
  a 
  gradual 
  decrease 
  to 
  a 
  velocity 
  of 
  about 
  2 
  

   knots 
  off 
  St. 
  Augustine, 
  Fla., 
  in 
  latitude 
  30° 
  N. 
  Here 
  the 
  Gulf 
  Stream 
  

   is 
  joined 
  by 
  the 
  Antilles 
  Current, 
  which 
  flows 
  northwesterly 
  along 
  the 
  

   open 
  ocean 
  side 
  of 
  the 
  West 
  Indies 
  before 
  uniting 
  with 
  the 
  Gulf 
  

   Stream. 
  

  

  North 
  of 
  the 
  thirtieth 
  parallel 
  of 
  latitude, 
  therefore, 
  the 
  Gulf 
  

   Stream 
  is 
  a 
  current 
  to 
  which 
  two 
  branches 
  have 
  contributed. 
  It 
  is 
  no 
  

   longer 
  merely 
  a 
  continuation 
  of 
  the 
  current 
  that 
  flows 
  through 
  the 
  

   Straits 
  of 
  Florida. 
  The 
  latter 
  current, 
  for 
  distinction, 
  is 
  frequently 
  

   referred 
  to 
  as 
  the 
  Florida 
  Current. 
  As 
  to 
  the 
  relative 
  importance 
  of 
  

   the 
  two 
  branches 
  of 
  the 
  Gulf 
  Stream 
  widely 
  varying 
  opinions 
  have 
  been 
  

  

  " 
  Schott, 
  op. 
  cit., 
  PI. 
  XIV, 
  following 
  p. 
  144. 
  

  

  