of positions was assimilated in full by Ptolemy and used by astronomer, Edmund Halley. Today, astronomy catalogues still refer to his work.
Ptolemy, however, had a greater effect in establishing the preeminent forms of astronomy, cosmology and astrology which ruled the next millennium. Although inaccurate as far as depicting the orbital relations, his work fixed the mapping, naming and designations for the divisions along the zodiac belt over the course of the year, initiating on the vernal equinox, as concurrent to the beginning of Aries. Ptolemy""s lasting work is his thesis on astrology, the Tetrabiblios, that eternally fixed the astrological zodiac sign on the vernal equinox as Aries 0xc2x0 for Western xe2x80x9ctropicalxe2x80x9d astrology, also named the xe2x80x9cmoving zodiacxe2x80x9d.
At the time of Hipparchus, the actual observable constellations were usedxe2x80x94this isthe vernal equinox to nearly accurate positions of his time, when he fixed this location of the equinox zodiac position, the zodiac constellations became, increasingly over time, factitious signs.
His failure to incorporate precession is understandablexe2x80x94did he think his system and records would be in use two thousand years later when precession was relevant? Second, current arguments say that Aries, the first sign, represents the new, fresh beginning of Spring, with its expansion and growth into Summer, and hence, must mark the vernal equinox. But this ignores the fact that on each vernal equinox, in the Southern Hemisphere, the equinox marks the beginning of Autumn, the end of Summer, and the coming contraction in Winter.
Nonetheless, even on the basis of claiming to prefer their methods because of the seasonal