his same principle of temperature, then, is
one of the causes of the Gulf Stream. The torrid zone is the furnace
where the waters of the ocean are heated. But in this process of
heating, evaporation goes on to a large extent; hence the waters become
salter than those elsewhere. Here is another agent called into action.
The hot salt waters of the torrid zone at once rush off to distribute
their superabundant caloric and salt to the seas of the frigid zones;
where the ice around the poles has kept the waters cold, and the absence
of great heat, and, to a large extent, of evaporation, has kept them
comparatively fresh. In fact, the waters of the sea require to be
stirred, because numerous agents are at work day and night, from pole to
pole, altering their specific gravity and deranging, so to speak, the
mixture. This stirring is secured by the unalterable laws which the
Creator has fixed for the carrying on of the processes of nature. The
currents of the sea may be said to be the result of this process of
stirring its waters.

It is curious and interesting to note the apparently insignificant
instruments which God has seen fit to use in the carrying out of his
plans. The smallest coral insect that builds its little cell in the
southern seas exercises an influence in the production of the Gulf
Stream. It has been said, with some degree of truth, that one such
insect is capable of setting in motion the entire ocean! The coral
insect has, in common with many other marine creatures, been gifted with
the power of extracting from sea water the lime which it contains, in
order to build its cell. The lime thus extracted leaves a minute
particle of water necessarily destitute of that substance. Before that
particle can be restored to its original condition of equality, every
other particle of water in the ocean must part with a share of its
superabundant lime! The thing _must_ be done. That bereaved particle
cannot rest without its lime. It forthwith commences to travel for the
purpose of laying its brother-particles under contribution; and it
travels far and wide--round and round the world. Myriads upon myriads
of coral insects are perpetually engaged in thus robbing the sea water
of its lime; shells are formed in a similar manner: so that our particle
soon finds itself in company with innumerable other particles of water
in a like destitute condition. It rises to the surface. Here the sun,
as if to compensate it