The mirror., 1921-04-07

stream, you should put before your eyes
world map or globe and look particu-
larly at the outline of the American coast
from Cape ST. Rogue, at the northeastern
corner of South America, to Nova Scotia.
You will perceive that between North
and South America the Atlantic makes a
huge indentation, the deepest points of
which are marked by the Caribbean sea
and the Gulf of Mexico. These are like
a double pocket, of which the Caribbean
is the upper portion, with wide opening
to the sea, while the Gulf is the deeper
part, connected with the Caribbean by a
restricted neck, and having small hole
out into the ocean between Cuba and the
southern point of Florida.
With these geographical facts before
you, consider meteorological fact hav-
ing direct relation to them. This is the
existence of great planetary system of
winds, connected with the rotation of the
earth, of which the "trade winds" are the
only portion that specially concerns us
degrees on each side of the equator, blow
ing constantly westward across the Allan
tic. One effect of these winds is to main
tain a general westward current of water
on the surface of the sea. There are many
details and divisions of this which we
may, for our purpose, ignore.
The surface water thus driven west
ward meets the incurved American coast
and while part of it is driven directly to
the mouth of the Caribbean, larger part
comes sliding up along the sloping shoul-
der of South America and enters the same
mouth. From the Caribbean the water
pours through the Yucatan channel into
the Gulf of Mexico, which is the bottom,
or inner part, of the pocket and from
which an exit is afforded by the "hole"
between Florida and Cuba. The result
of the crowding of the surface water from
the tropical Atlantic by the "trade winds"
into the cul-de-sac formed by the Gulf is
that the level of the latter is raised per-
mean level of the Atlantic.
The surplus water finds its way out of
the Gulf through the Strait of Florida, the
"hole" already mentioned, and being COM
pressed into narrow channel it flows
with considerable speed, estimated at
about FIVE miles an hour. It's width here
is about 50 miles and its depth averages
nearly 1000 feet. Its surface tempera-
ture is about 80 degrees Fahrenheit.
1t sweeps its bottom as clean as broom
would do. After emerging from the strait
it encounters another current which after
striking the West Indies from the east has
turned northward without entering the
Caribbean, and this outside current con-
tinues to flow parallel with the eastern
side of the Gulf stream.
The force and velocity of the Gulf
stream vary to some extent, but its course
does not materially change until it has
run hundreds of miles north-eastward off
the coast of the United States. Gradually
it does then shift its direction more west,.
ward, at the same time spreading like
fan and becoming shallower.
Of the banks of Newfoundland the
Gulf stream meets the cold Labrador cur
rent-the "cold WALL that borders our
northeast coast-with its burden of ice
bergs. Being colder, the water of this
current would naturally sink under that
of the Gulf stream, but this tendency is
apparently counteracted by its greater
buoyancy, due to the fact that it is less
salt than the water from the tropics. ut
is probable" says Hugh Robert Mill, "that
the cold current cuts horizontally through
the Gulf stream like a paper cutter
through the leaves of book and mixes
with the mass of the Atlantic water"
From this point the Gulf stream is wide
ly spread, or ocean divided into subsidiary
streams, and apart of its water touches Ice