1. There is a circular number of the stars by which it is said to be
known in what time each and every star finishes its orbit, whether in
longitude or latitude.[274]
[274] Du Breul has in addition: _latitudo intelligitur per
signiferum, longitudo per proprium excursum_.
2. For the moon is said to complete its orbit in eight years, Mercury
in twenty, Lucifer in nine, the sun in nineteen, Pyrois in fifteen,
Phaeton in twelve, Saturn in thirty. When these are finished,
they return to a repetition of their orbits through the same
constellations and regions.
3. Certain stars being hindered by the rays of the sun become
irregular, either retrograde or stationary, as the poet relates,
saying:
Sol tempora dividit aevi
Mutat nocte diem, radiisque potentibus astra
Ire vetat, cursusque vagos statione moratur.