The Astronomical Observatories of Jai Singh c20.s1.7

c20.s1.7

The ecliptic was divided into 12 equal divisions, or signs of the zodiac, which, owing to the obliquity, took different times to rise and set. This problem of ascensions (‘Ἀναφοραί) became of great importance, because it affected the position of the four ‘centres.’ (1) The ‘horoscope’ or ‘ascendant.’ (2) Superior culmination. (3) The descendant. (4) Inferior culmination. These, in consequence of the variable time of the risings and settings of the signs, are not at intervals of right angles, as the early ‘Egyptian’ astrologers assumed.