exeligmos

Ptolemy an exeligmos, solar eclipses recur at approximately the same place.

The History of the Former Han Dynasty 1938

If the eclipses occurring at intervals of an exeligmos are plotted on a map, it will be found that they form a series which has certain definite characteristics.

The History of the Former Han Dynasty 1938

Because of the shifting in longitude shown by some series, a determination of the approximate circumstances of a partial eclipse from umbral eclipses in the same exeligmos series is not reliable.

The History of the Former Han Dynasty 1938

China, and since the farther partial eclipses are from the nearest umbral eclipse in the same exeligmos series, the more they tend to move northwards, outside of Chinese latitudes.

The History of the Former Han Dynasty 1938

Conchoid curves are obtained for those eclipses in which the moon's penumbra reaches the northern limits to which the sun is visible; such eclipses are those near the ends of a saros or exeligmos series.

The History of the Former Han Dynasty 1938

Less than one-third of such partial eclipses are visible there, since only the eclipse at one of the three saroi in an exeligmos can usually be visible in

The History of the Former Han Dynasty 1938

If the nearest umbral eclipse in the same exeligmos series was visible near the north pole, we cannot say with any certainty by this method whether the partial eclipses in that series were visible in China.

The History of the Former Han Dynasty 1938

Since partial eclipses are those in which the moon's umbra (or its prolongation) passes over one of the earth's poles, and since successive eclipses in the same exeligmos series are located close to each other, it is possible to determine definitely that a partial solar eclipse was not visible

The History of the Former Han Dynasty 1938

A solar exeligmos series covers a period of from 1244 to 1532 years or 23 to 28 exeligmoi, with an initial and terminal run of 2 to 8 exeligmoi during which only partial eclipses occur.

The History of the Former Han Dynasty 1938

1 Besides those whose location Oppolzer charts, the following three partial eclipses were invisible because they belong to initial (i.) or terminal (t.) runs in exeligmos series whose nearest umbral eclipse was located near the south pole: no. 2389 (i.); no.

The History of the Former Han Dynasty 1938