Caelum Antiquum:
Ancient Astronomy and Astrology
Resources on LacusCurtius

[ complete English translation ]

For a thousand years, Ptolemy's Tetrabiblos was one of the most popular technical manuals in the world, that taught the rudiments of casting an astrological chart to many generations of practitioners.

(His greater work on the heavens — the Almagest — is not onsite yet.)

[ 12/28/07: complete: 486 pages of print ]

Allen's Star Names is a monumental 20c compendium on the origins of star names: Greek and Roman, but also Arabic and Babylonian and more exotic languages still; Dante and our English poets, and the heroic era of scientific astronomy, and here and there, other loosely related information that appealed to him. Flawed, superseded, but occasionally fascinating reading.

[ complete Latin text
(linked in the header to an English translation) ]

Book II of Pliny's Natural History: cosmology, the sun, moon and planets, comets and meteors; planetary motions and orbits; eclipses; the effects of the planets on weather and tides; the relation­ship between astronomy and geography.

[ complete Latin text and French translation ]

Censorinus' de Die natali is a major source of Roman calendrical information; but also includes material on the zodiac and gestation, the Pythagorean musical organization of the heavens, the climacterics, the Etruscan "centuries", cosmological cycles, and sundials.

[ complete English translation ]

Plutarch's Isis and Osiris is a cerebral mix of cosmology and philosophy, in which the sun, the moon and their influences figure prominently.

[ complete English translation ]

Plutarch's On the Face in the Moon is another even more deadly cerebral mix of cosmology and philosophy, which will keep the enquiring mind busy for a very long time.

[ Greek text, English translation ]

In Diogenes Laertius' Lives of Famous Philosophers we have two fairly important texts on ancient astronomy:

a rather full exposition of Stoic notions of the universe and astronomy (VII.140‑146);

and something very much like the complete text of Epicurus's epistle on Celestial Phenomena (X.84‑116) covering the sun and moon, their motions, their light, and eclipses; comets and falling stars — with a good deal of meteorology mixed in.

[ 8/24/07: in progress ]

Smith's Dictionary of Greek and Roman Antiquities includes a few articles on the ancient heavens and related material. The main one, Astronomia, runs to 40,000 words — and I haven't got around to putting it online. The following articles, however, are available:

Astrologia • Clima • Horologium • Polus

The 1911 Encyclopaedia Britannica also has a number of articles on astronomy and astrology, often written by top authorities. I don't expect to put many of them up, but they're occasionally cited on other pages of mine, so it'll prove useful to transcribe some of them. For now, just one: Zodiac.

The Roman architect Vitruvius surprisingly states​† that architecture consists of three branches: the construction of buildings, of engines of war — and of sundials; and so he covers sundials, along with much astronomy, in Book IX of his de Architectura. The diligent student could also do worse than read the rest of Vitruvius as well, in which astronomy or the influence of the luminaries appears, in one way or another, in every book except III and IV.

Cicero, in the de Divinatione, spends a fair amount of ink on astronomy and astrology: he distinguishes them and judges the latter to be rank superstition. The most relevant section is Book II.42.87‑47.99, but the topic crops up frequently thruout the work.

Continuing in the sceptical vein, Gellius reports a lecture of the philosopher Favorinus, who says astrology is bunk and explains why: Attic Nights, XIV.1 (for now, in Latin only).

Midway between belief in astrology and total scepticism, we have the agnosticism of a great historian, and an interesting incident, likely enough to be true that he reported it: Tacitus, Annals, VI.20‑22.

The 6c encyclopedist Isidore has something to say on astronomy; about half a Book's worth: Orig. III, chs. 24‑end.

The historian Ammian devotes a rather long passage of Book XX of his Roman History to solar eclipses. He's rather shaky on the whole concept. . . .

And finally, very brief, but fascinating: the Late Antique poet Claudian wrote verses on Archimedes' Sphere that give us a tantalizing glimpse into the mechanics of what seems to have been a rather complex orrery of sorts.