Among them is the Portuguese Astronomical
Ephemeris for the meridian of the University of Coimbra, prepared
for Portuguese navigators. I do not know whether the Portuguese
navigators really reckon their longitudes from this point: if they
do the practice must be attended with more or less confusion. All
the matter is given by months, as in the solar and lunar ephemeris
of our own and the British Almanac. For the sun we have its
longitude, right ascension, and declination, all expressed in arc
and not in time. The equation of time and the sidereal time of
mean noon complete the ephemeris proper. The positions of the
principal planets are given in no case oftener than for every
third day. The longitude and latitude of the moon are given for
noon and midnight. One feature not found in any other almanac is
the time at which the moon enters each of the signs of the zodiac.
It may be supposed that this information is designed rather for
the benefit of the Portuguese landsman than of the navigator. The
right ascensions and declinations of the moon and the lunar
distances are also given for intervals of twelve hours. Only the
last page gives the eclipses of the satellites of Jupiter. The
Fixed Stars are wholly omitted.
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