This diagram showing the structure of the cosmos comes from Nicephorus Blemmydes’ “Epitome physica.” At the center is the sphere of elemental earth surrounded by a narrow sphere of water. Then a broad sphere of air surrounds them capped by the sphere of fire. Separating the elements from the heaves is the sphere of the moon. Beyond that is the ether, the “ΑΙΘΗΡ,” where we see planets and stars. Beyond this is the “Water beyond the heavens” surrounded by the “Place of the angels.” A hierarchy of nine levels of angels, archangels, and beyond culminates in the Trinity at the top.
Born just before the Latins sacked Constantinople in 1204, Blemmydes fled the capital and studied mathematics, medicine, astronomy, logic, as well as theology and rhetoric in Asia Minor, especially Nicaea. He participated in the controversies between the Eastern and Western Churches, agreeing with the Western Church’s beliefs on such issues as the procession of the Holy Ghost from the Father through the Son. He was also renowned for establishing a school, where the young George Akropolites studied. Like so many Byzantine polymaths, he ultimately retired from public life to a monastery he had built.
This diagram represents the geocentric cosmos, with the earth (γῆ) at the center, surrounded by spheres of the Moon (σελήν), Mercury (ἐρμῆς), Venus (ἀφροδίτη), the sun, Mars (ἄρης), Jupiter (ζεύς), and Saturn (κρόνος). An incomplete ring for the signs of the zodiac encircles the planetary spheres—only the symbol for Aries was added. Finally, the names of the zodiac were labeled in red on the outside, starting at 3 o’clock and proceeding counter clockwise:
Capricorn (αἰγώκερως (should be αἰγόκερως))
This diagram is part of a collection of astronomical diagrams in Royal MS 16 C XII, a latter 16th-century manuscript first owned by the brilliant classical scholar and historian Isaac Casaubon. Other texts in the in the codex all concern the construction and use of the astrolabe (the first text is a printed edition from 1544, the rest are manuscripts).
The ordering of the planets in this diagram poses a bit of a puzzle. As labeled, it suggests that the planetary order was: Moon, Mercury, Venus, Mars, [sun], Jupiter, Saturn. I’ve never come across that order before, i.e., Mars below the sun. What makes more sense is that the sun’s sphere, the fourth from the center, is instead labeled “ἄρης” because Mars’s sphere had been colored black (possibly before labeling any of them). Then, since writing wouldn’t show up on the black sphere, the person labeled Mars on the sphere below it, the sun’s. ↩