What Is In
Salt is, of course, the most common
substance found in sea water, but it is far from being
the only one. One hundred pounds of sea water, if boiled
away, will leave behind close to 3.5 pounds of solids.
A map showing the named ocean currents of the
is the second largest ocean current. At its greatest the Gulf Stream is approximately
100 miles wide and several hundred feet deep -- far
larger than any river on earth. It also flows faster than
any known river, up to 138 miles (222 kilometers) a day.
The Sargasso Sea
is a creation of the great currents of the
North Atlantic that encircle it and bring into it the
millions of tons of floating sargassum weed from which
the place takes its name. Those same currents also make
the waters within the sea very clear and salty.
published the first popular textbook on marine science, Physical
Geography of the Sea, in 1855. During the Civil War,
his work for the Confederacy led to a $3,000 price being
put on his head, second only to the price put on the head
of Confederate President Jefferson Davis.