s are intently fixed. This
constellation was a little nearer the pole in former ages than at the
present time; still its distance was always so great that its use as a
mark of the northern point of the horizon does not inspire us with
great respect for the accuracy with which the ancient navigators sought
to shape their course.

The Nautical Almanac of the present day had its origin in the
Astronomical Ephemerides called forth by the needs of predictions of
celestial motions both on the part of the astronomer and the citizen.
So long as astrology had a firm hold on the minds of men, the positions
of the planets were looked to with great interest. The theories of
Ptolemy, although founded on a radically false system, nevertheless
sufficed to predict the position of the sun, moon, and planets, with
all the accuracy necessary for the purposes of the daily life of the
ancients or the sentences of their astrologers. Indeed, if his tables
were carried down to the present time, the positions of the heavenly
bodies would be so few degrees in error that their recognition would be
very easy. The times of most of the eclipses would be predicted within
a few hours, and the conjunctions of the planets within a few days.
Thus it was possible for the astronomers of the Middle Ages to prepare
for their own use, and that of the people, certain rude predictions
respecting the courses of the sun and moon and the aspect of the
heavens, which served the purpose of daily life and perhaps lessened
the confusion arising from their complicated calendars. In the signs of
the zodiac and the different effects which follow from the sun and moon
passing from sign to sign, still found in our farmers' almanacs, we
have the dying traces of these ancient ephemerides.

The great Kepler was obliged to print an astrological almanac in virtue
of his position as astronomer of the court of the King of Austria. But,
notwithstanding the popular belief that astronomy had its origin in
astrology, the astronomical writings of all ages seem to show that the
astronomers proper never had any belief in astrology. To Kepler himself
the necessity for preparing this almanac was a humiliation to which he
submitted only through the pressure of poverty. Subsequent ephemerides
were prepared with more practical objects. They gave the longitudes of
the planets, the position of the sun, the time of rising and setting,
the prediction of eclipses, etc.

They have, of course, g