vine
order, their appearance indicates some irregularity in the government of
the Celestial Empire. Accordingly, they are received with all kinds of
expiatory ceremonies prescribed thousands of years ago, and still in
force to-day.
In the twentieth century, as in the nineteenth, the eighteenth, or in
ancient epochs, the same awe and terror operates upon the ignorant
populations who abound upon the surface of our planet.
To return to astronomical realities.
We said above that these phenomena were produced when the Full Moon and
the New Moon reached the line of intersection, known as the line of
nodes, when the plane of the lunar orbit cuts the plane of the ecliptic.
As this line turns and comes back in the same direction relatively to
the Sun at the end of eighteen years, eleven days, we have only to
register the eclipses observed during this period in order to know all
that will occur in the future, and to find such as happened in the past.
This period was known to the Greeks under the name of the Metonic Cycle,
and the Chaldeans employed it three thousand years ago under the name of
Saros.
On examining this cycle, composed of 223 lunations, we see that there
can not be more than seven eclipses in one year, nor less than two. When
there are only two, they are eclipses of the Sun.
The totality of a solar eclipse can not last more than seven minutes,
fifty-eight seconds at the equator, and six minutes, ten seconds in the
latitude of Paris. The Moon, on the contrary, may be entirely eclipsed
for nearly two hours.
Eclipses of the Sun are very rare for a definite spot. Thus not one
occurred for Paris during the whole of the nineteenth century, the last
which happened exactly above the capital of France having been on May
22, 1724. I have calculated all those for the twentieth century, and
find that two will take place close to Paris, on April 17, 1912, at
eighteen minutes past noon (total for Choisy-le-Roi, Longjumeau, and
Dourdan, but very brief: seven seconds), and August 11, 1999, at 10.28
A.M. (total for Beauvais, Compiegne, Amiens, St. Quentin, fairly long:
two minutes, seventeen seconds). Paris itself will not be favored before
August 12, 2026. In order to witness the phenomenon, one must go and
look for it. This the author did on May 28, 1900, in Spain.
The progress of the lunar shadow upon the surface of the Earth is traced
beforehand on maps that serve to show the favored countries for which
our sate
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