knowledge of the ocean is still only in the preliminary stage. The
ocean has an area twice as great as that of the dry land, and it
occupies a space thirteen times as great as that occupied by the
land above sea-level. Apart from the great number of soundings for
depth alone, the number of oceanographical stations -- with a series
of physical and biological observations at various depths -- is very
small in proportion to the vast masses of water; and there are still
extensive regions of the ocean of the conditions of which we have
only a suspicion, but no certain knowledge. This applies also to the
Atlantic Ocean, and especially to the South Atlantic.

Scientific exploration of the ocean has several objects. It seeks to
explain the conditions governing a great and important part of our
earth, and to discover the laws that control the immense masses of
water in the ocean. It aims at acquiring a knowledge of its varied
fauna and flora, and of the relations between this infinity of
organisms and the medium in which they live. These were the principal
problems for the solution of which the voyage of the Challenger and
other scientific expeditions were undertaken. Maury's leading object
was to explain the conditions that are of practical importance to
navigation; his investigations were, in the first instance, applied
to utilitarian needs.

But the physical investigation of the ocean has yet another very
important bearing. The difference between a sea climate and a
continental climate has long been understood; it has long been known
that the sea has an equalizing effect on the temperature of the air,
so that in countries lying near the sea there is not so great a
difference between the heat of summer and the cold of winter as on
continents far from the sea-coast. It has also long been understood