Supplementary
excerpts from the Almagest Book 1, translated by Toomer.
Ptolemy describes his picture of the universe and goes through, point be point, to justify that picture.
We know from other sources that Ptolemy was summarizing what was broadly accepted in his time and had been developed over a period of many centuries:
excerpts from Theon of Smyrna, written about a generation earlier than Ptolemy, that are eerily similar to Ptolemy’s text.
excerpts from Plutarch, written in the first century A.D.: Books II and II of Concerning Nature and The Face in the Moon, all with some interesting astronomical comments.
excerpts from Strabo’s Geography, written early in the first century A.D., that also cover much of the same material.
excerpts from Geminus, written about 50 B.C., plus some commentary, all from James Evans, The History and Practice of Ancient Astronomy.
excerpts from Autolycus, written about 300 B.C.
excerpts from the famous poem Phenomena of Aratus, written about 275 B.C., but we are told by Hipparchus (130 B.C.) that Aratus takes his material directly from the astronomer Eudoxus, who worked near 320 B.C.
excerpts from Aristotle On the Heavens, written about 350 B.C.
If we go back even further, the very earliest surviving Greeks works, those by Homer and Hesiod written in about 750 B.C., do mention aspects of celestial phenomena, but do not have the picture of the celestial sphere developed no later than Eudoxus. It would be surprising if the concept had existed and they did not mention it.