IX

THE MARINER'S COMPASS


Among those provisions of Nature which seem to us as especially
designed for the use of man, none is more striking than the
seeming magnetism of the earth. What would our civilization have
been if the mariner's compass had never been known? That Columbus
could never have crossed the Atlantic is certain; in what
generation since his time our continent would have been discovered
is doubtful. Did the reader ever reflect what a problem the
captain of the finest ocean liner of our day would face if he had
to cross the ocean without this little instrument? With the aid of
a pilot he gets his ship outside of Sandy Hook without much
difficulty. Even later, so long as the sun is visible and the air
is clear, he will have some apparatus for sailing by the direction
of the sun. But after a few hours clouds cover the sky. From that
moment he has not the slightest idea of east, west, north, or
south, except so far as he may infer it from the direction in
which he notices the wind to blow. For a few hours he may be
guided by the wind, provided he is sure he is not going ashore on
Long Island. Thus, in time, he feels his way out into the open
sea. By day he has some idea of direction with the aid of the sun;
by night, when the sky is clear he can steer by the Great Bear, or
"Cynosure," the compass of his ancient predecessors on the
Mediterranean. But when it is cloudy, if he persists in steaming