﻿292 
  

  

  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  19 
  29 
  

  

  Nautical 
  Miles 
  

  

  20 
  30 
  

  

  Fathoma 
  

  

  cubic 
  feet 
  per 
  second.^" 
  On 
  converting 
  these 
  figures 
  into 
  cubic 
  (geo- 
  

   graphical) 
  miles 
  per 
  hour 
  they 
  become, 
  respectively, 
  0.01 
  and 
  0.03 
  

   cubic 
  mile. 
  The 
  14 
  cubic 
  miles 
  which 
  the 
  Gulf 
  Stream 
  hourly 
  pours 
  

   into 
  the 
  sea 
  is 
  thus 
  more 
  than 
  1,000 
  times 
  the 
  average 
  discharge 
  and 
  

   very 
  nearly 
  500 
  times 
  the 
  extreme 
  flood 
  discharge 
  of 
  the 
  Mississippi. 
  

  

  THE 
  WATER 
  WITHIN 
  THE 
  STRAITS 
  OF 
  FLORIDA 
  

  

  With 
  regard 
  to 
  the 
  water 
  poured 
  so 
  prodigally 
  by 
  the 
  Gulf 
  Stream 
  

   into 
  the 
  sea 
  through 
  the 
  Straits 
  of 
  Florida, 
  the 
  generally 
  accepted 
  

   notion 
  is 
  that 
  it 
  is 
  of 
  an 
  unusually 
  high 
  temperature 
  from 
  top 
  to 
  

   bottom. 
  Figure 
  4 
  shows 
  the 
  temperature 
  of 
  the 
  water, 
  in 
  degrees 
  

   Fahrenheit, 
  across 
  the 
  section 
  in 
  the 
  straits 
  from 
  Cape 
  Florida 
  east- 
  

   ward. 
  This 
  is 
  adapted 
  from 
  Wiist, 
  who 
  made 
  use 
  of 
  observations 
  

  

  taken 
  in 
  May, 
  1878, 
  and 
  in 
  

   March, 
  1914. 
  Since, 
  in 
  general, 
  

   the 
  sea 
  in 
  the 
  Northern 
  Hemi- 
  

   sphere 
  is 
  coldest 
  in 
  February 
  

   and 
  warmest 
  in 
  August, 
  it 
  may 
  

   be 
  taken 
  that 
  the 
  temperatures 
  

   shown 
  in 
  Figure 
  3 
  are 
  approxi- 
  

   mately 
  average 
  temperatures. 
  

  

  Obviously 
  the 
  Gulf 
  Stream 
  in 
  

   the 
  straits 
  is 
  not 
  a 
  homogeneous 
  

   body 
  of 
  warm 
  water. 
  At 
  the 
  sur- 
  

   face, 
  in 
  the 
  center 
  of 
  the 
  channel, 
  

   the 
  temperature 
  is 
  about 
  80°, 
  and 
  

   at 
  the 
  bottom 
  it 
  is 
  45° 
  or 
  even 
  

   less. 
  The 
  fall 
  in 
  temperature 
  is 
  

   fairly 
  rapid, 
  a 
  temperature 
  of 
  50° 
  

   being 
  attained 
  at 
  about 
  200 
  fathoms, 
  so 
  that 
  only 
  a 
  relatively 
  shallow 
  

   layer 
  of 
  the 
  water 
  is 
  warm. 
  

  

  Figure 
  3 
  brings 
  to 
  light 
  the 
  fact 
  that 
  for 
  any 
  given 
  depth 
  the 
  

   water 
  on 
  the 
  eastern 
  side 
  of 
  the 
  channel 
  is 
  considerably 
  warmer 
  than 
  

   that 
  on 
  the 
  western. 
  Thus 
  at 
  a 
  depth 
  of 
  100 
  fathoms 
  the 
  water 
  on 
  the 
  

   Florida 
  side 
  of 
  the 
  straits 
  has 
  a 
  temperature 
  of 
  about 
  50°, 
  while 
  on 
  

   the 
  Bahama 
  side 
  the 
  temperature 
  is 
  about 
  70°. 
  Furthermore, 
  while 
  

   the 
  change 
  in 
  temperature 
  with 
  depth 
  is 
  approximately 
  uniform 
  on 
  the 
  

   Bahama 
  side, 
  it 
  is 
  decidedly 
  not 
  uniform 
  on 
  the 
  Florida 
  side, 
  where 
  a 
  

   rapid 
  change 
  of 
  20° 
  in 
  temperature 
  takes 
  place 
  between 
  the 
  depths 
  

   of 
  50 
  and 
  100 
  fathoms. 
  As 
  regards 
  temperature 
  therefore, 
  the 
  water 
  

   of 
  the 
  Gulf 
  Stream 
  is 
  decidedly 
  not 
  homogeneous. 
  

  

  The 
  prevailing 
  conception 
  of 
  the 
  Gulf 
  Stream 
  as 
  an 
  unusually 
  warm 
  

   body 
  of 
  water 
  can 
  be 
  shown 
  as 
  erroneous 
  from 
  another 
  point 
  of 
  view, 
  

  

  Figure 
  4.— 
  Temperature 
  of 
  Gulf 
  Stream 
  

   within 
  Straits 
  of 
  Florida 
  

  

  '• 
  J. 
  L. 
  Greenleaf: 
  The 
  Hydrology 
  of 
  the 
  Mississippi, 
  Amer. 
  Journ. 
  of 
  Scl., 
  Ser. 
  4, 
  Vol. 
  2, 
  pp. 
  29-46 
  1896; 
  

   reference 
  on 
  p. 
  42, 
  

  

  