Climata

kly-MAH-tah

Definition

The climata (Greek klimata, singular klima, "inclination" or "slope") are the ancient way of dividing the inhabited world into latitude bands, each band keyed to the length of its longest day. The standard seven-climata scheme, used from the 3rd century BCE onward, runs across longest-day values from about 13 to 16 equinoctial hours; each clima carries its own table of zodiac rising times for working out the ascendant. Think of it as a rough stand-in for latitude, used before latitude was measured directly.

In Tradition

Rochberg argues that the seven-climata system carries leftover Babylonian oblique ascensions far into the medieval period: the Greek and medieval geography that frames the climata is a survival from the Mesopotamian rising-time apparatus, not a fresh Greek invention. Ptolemy's ten-latitude table in *Almagest* II.8 adapts the Babylonian System A scheme to other latitudes; the seven-climata tradition is the looser, more geographical condensing of the same machinery.

In Practice

For the Hellenistic astrologer, the clima you are in decides which rising-time table you consult to turn the Sun's position into the position of the ascendant — the degree rising on the eastern horizon. Paulus Alexandrinus (4th c. CE) writes for Clima 3 (Alexandria, longest day 14 equinoctial hours); Vettius Valens supplies tables for other climata. The clima also feeds into length-of-life techniques — primary directions and the bound-lord apparatus — where the rising times of the chart's key figures depend on this latitude stand-in. The seven-climata framework keeps going in medieval Arabic and Latin geographical astronomy long after Ptolemy's more precise latitude framework was available.

Historical Origin

The seven-climata scheme is standard from the Hellenistic period onward (3rd c. BCE to 3rd c. CE) and appears in Eratosthenes, Hipparchus, Strabo, Ptolemy's *Geography* and *Almagest* II.8, and Paulus Alexandrinus' *Introductory Matters*. The descent from Babylonian rising times is documented by Rochberg, *The Heavenly Writing* (Cambridge 2004) Ch. 7 §7.1; Hunger & Pingree, *Astral Sciences in Mesopotamia* (Brill 1999); and Neugebauer, *A History of Ancient Mathematical Astronomy* (Springer 1975).

Further Reading

  • Francesca Rochberg, The Heavenly Writing: Divination, Horoscopy, and Astronomy in Mesopotamian Culture
  • Hermann Hunger & David Pingree, Astral Sciences in Mesopotamia
  • Otto Neugebauer, A History of Ancient Mathematical Astronomy