ed to be a mystery. It
was in the earliest times perceived that there was a connection between
the tides and the moon. Ancient writers, such as Pliny and Aristotle,
have referred to the alliance between the times of high water and the
age of the moon. I think we sometimes do not give the ancient
astronomers as much credit as their shrewdness really entitles them to.
We have all read--we have all been taught--that the moon and the tides
are connected together; but how many of us are in a position to say that
we have actually noticed that connection by direct personal observation?
The first man who studied this matter with sufficient attention to
convince himself and to convince others of its reality must have been a
great philosopher. We know not his name, we know not his nation, we know
not the age in which he lived; but our admiration of his discovery must
be increased by the reflection that he had not the theory of gravitation
to guide him. A philosopher of the present day who had never seen the
sea could still predict the necessity of tides as a consequence of the
law of universal gravitation; but the primitive astronomer, who knew not
of the invisible bond by which all bodies in the universe are drawn
together, made a splendid--indeed, a typical--inductive discovery, when
he ascertained the relation between the moon and the tides.

We can surmise that this discovery, in all probability, first arose from
the observations of experienced navigators. In all matters of entering
port or of leaving port, the state of the tide is of the utmost concern
to the sailor. Even in the open sea he has sometimes to shape his course
in accordance with the currents produced by the tides; or, in guiding
his course by taking soundings, he has always to bear in mind that the
depth varies with the tide. All matters relating to the tide would thus
come under his daily observation. His daily work, the success of his
occupation, the security of his life, depend often on the tides; and
hence he would be solicitous to learn from his observation all that
would be useful to him in the future. To the coasting sailor the
question of the day is the time of high water. That time varies from
day to day; it is an hour or more later to-morrow than to-day, and there
is no very simple rule which can be enunciated. The sailor would
therefore welcome gladly any rule which would guide him in a matter of
such importance. We can make a conjecture as to the man