ow 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.
An old ephemeris, and one well known in astronomy is that published by
the Observatory of Milan, Italy, which has lately entered upon the
second century of its existence. Its data are extremely meagre and of
no interest whatever to the navigator. The greater part of the volume
is taken up with observations at the Milan Observatory.
Since taking charge of the American Ephemeris I have endeavored to
ascertain what nautical almanacs are actually used by the principal
maritime nations of Europe. I have been able to obtain none except
those above mentioned. As a general rule I think the British Nautical
Almanac is used by all the northern nations, as already indicated. The
German Nautical Jahrbuch is principally a reprint from the British. The
Swedish navigators, being all well acquainted with the English
language, use the British Almanac without change. The Russian
government, however, prints an explanation of the various terms in the
language of their own people and binds it in at the end of the British
Almanac. This explanation includes translations of the principal terms
used in the heading of pages, such as the names of the months and days,
the different planets, constellations, and fixed stars, and the
phenomena of angle and time. They have even an index of their own in
which the titles of the different articles are given in Russian. This
explanation o
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