Tag: Byzantine Science

Nicephorus Gregoras’s “περὶ κατασκευῆς … ἀστρολάβου”

An illustration of a rete from a 15th-century copy of Nicephorus Gregoras’s “περὶ κατασκευῆς καὶ γενέσεως ἀστρολάβου,” BN suppl. graec. 0652, fol. 285v.

A nice drawing of the rete from Nicephorus Gregoras’s “περὶ κατασκευῆς καὶ γενέσεως ἀστρολάβου” (“On the Mathematical Origin and Construction of the Astrolabe”). This rete, like other diagrams in copies of Gregoras’s text, lacks stars and finer details. In the few copies I’ve seen that include the stars, the rete closely resembles the one surviving Byzantine astrolabe, especially the number and style of the star pointers.

The only Byzantine astrolabe known to survive dates from the 11th century and reflects the style of other early, Islamic astrolabes. Today this astrolabes is in Brescia.

Interesting, at least to me, is the fact that the illustrations in different copies of Gregoras’s text often label the diagrams in different ways. In this copy diagrams are labeled counterclockwise starting at the 9 o’clock position, e.g., the diagrams on fol. 284v of BN suppl. graec. 0652. In other copies, diagrams are labeled counterclockwise or clockwise from various starting points (the 9 o’clock position is the most common starting point). In one manuscript, diagrams on consecutive folia are labeled in opposite ways. The absence of illustration in many copies of Gregoras’s work makes it challenging to follow the text. In most such cases, the copyist left no room for illustrations, suggesting he was working from an unillustrated copy. In some manuscripts, the copyist left large spaces for the illustrations.

A Wolf-Headed Byzantine Veterinarian

A wolf-headed man binds a horse’s leg in this illustration “On Fractures” from a 15th-century copy of the “Hippiatrica”, University of Leiden, VSQ 50, fol. 68r.

The Hippiatrica assembles treatments for a wide range of ailments and injuries horses might suffer. The work itself is a collection from various other treatises by authors—e.g., Eumelos, Apsyrtos, Anatolios, Pelagonius, Themnestos, and Hierocles—and was probably assembled sometime between the 5th and the 10th centuries. In this illustration from a 15th-century Italian copy (now in Leiden), a wolf-headed man binds a horse’s fractured leg, the caption says “περὶ κατεαγμάτων” or “On Fractures.” What makes this illustration so amazing is the wolf-like creature caring for the horse. This illustration (like others in the manuscript) closely resembles, in most ways, illustrations in other copies of the Hippiatrica.

A man binds a horse’s fractured leg in late 14th-century copy of the Hippiatrica, Paris, BN graec. 2244, fol. 36v.

But unlike the stern but generally non-threatening looking man in the BN copy, the man (?) in the the Leiden copy is rather scary looking, with his wolf’s head and long tongue threatening the horse. There are other strange creatures depicted in this manuscript caring for horses, such as the footless, dragon-bird monster treating a horse for an ulcer.

A strange footless, dragon-bird hybrid treats a horse for an ulcer in the chapter “On Ulcers” from a 15th-century copy of the “Hippiatrica”, University of Leiden, VSQ 50, fol. 70r.

I know so little about Byzantine veterinary medicine, but am now intrigued. I think I’ve found my holiday reading: Anne Elena McCabe, A Byzantine encyclopaedia of horse medicine (OUP, 2007).[1]

Anne Elena McCabe, A Byzantine encyclopaedia of horse medicine (OUP, 2007) looks promising, but sorry OUP, I can’t afford $155 for a book.

  1. Alas, I will have to wait until the new year, since I have to request a copy though ILL. OUP prices are too high for a) our library or b) me to justify buying a copy. Seriously OUP? $155 for a single volume? That is outrageous! There is something wrong with the business that raises the prices at the expense of selling more copies. Whose interests are served by this? Not the author’s, who presumably would like people to read and benefit from her work and who might enjoy even a small royalty check now and then.  ↩

Byzantine Structure of the Cosmos

A diagram showing the nature of the cosmos from earth at the center to God at the top, passing through the various levels‚—e.g., the elements, ether, angles—from a 16th-century copy of Nicephorus Blemmydes’ “Epitome physica” Oxford, Bodleain Barocci 94, fol. 27v.

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.

A Byzantine form of Geomancy?

A figure that correlates the planets, signs of the zodiac, and figures, which seems to be related to some geomancy of some form. “Cleromancy,” Harley MS 5596, fol. 4v.

This illustration from a 15th-century manuscript seems to be a type of geomantic figure that correlates the planets, signs, and figures (arrangements of dots). It shows the standard astrological relationships between planets and signs. Starting at the top and proceeding counterclockwise from the moon:

  • Moon — Cancer
  • Mercury — Gemini and Virgo
  • Venus — Taurus and Libra
  • Sun — Leo
  • Mars — Aries and Scorpio
  • Jupiter — Sagittarius and Pisces
  • Saturn — Capricorn and Acquarius

We also see a figure of dots associated with each planet/sign combination.

The planets and signs are each associated with a pattern of dots, as they are in geomancy. Here the planets and signs have been labeled.

In its most generic sense, geomancy involved interpreting random markings of dots. Four rows of dots were grouped into figures, each named, associated with a planet, a sign, day or night, and other properties. There were sixteen such figures. This diagram was, perhaps, a form of geomancy or a related mantic practice (the generic title given to this work, “cleromancy”—divination by drawing lots, seems more closely related to the first figure than to this one.)

Various forms of divination were widely practiced (or at least discussed) throughout the Byzantine world, ranging from the recognizable astrology and necromancy to the relatively obscure (at least today) catoptromancy and lecanomancy—divination through interpreting images in mirrors or patterns in liquids in bowls. Both practices could both be part of long and complicated rituals that compelled demons to appear on the surface of the liquid or in the mirror. The demons could be commanded to reveal the future.

Apollodorus’s Siege Tower

An illustration from a Byzantine copy of Apollodorus of Damascus’s “Πολιορκητικά” showing a siege tower with an assault bridge for scaling walls. This drawing is from BNF suppl. gr. 607, fol. 38r, a manuscript dated sometime between the 11th and 14th centuries.

Apollodorus of Damascus is generally thought to have written the “Πολιορκητικά,” a treatise on siege engines, addressed to an unnamed emperor (probably Trajan). The text first treats siege engines used to besiege a hilltop fort, machines to protect troops from objects rolled down the hill as well as devices for protecting men attacking the base of the walls. It describes devices for drilling through walls and setting fire to walls as well as sheds for battering rams. The text also describes towers used to scale walls and invade a fort as well as towers with pivoting arms to sweep defenders off the walls.

This image of a siege tower with bridge is a common illustration in Apollodorus manuscripts, as seen in this 15th-century copy of Apollodorus’s “Πολιορκητικά” in Oxford, Magdalen College, fonds principal gr. 14, fol. 37v

Apollodorus worked on various engineering and building projects for the emperor Trajan in the early second century CE. He was responsible for such projects as Trajan’s Bridge over the Danube during the campaign in Dacia, Trajan’s Column and Trajan’s Forum, various triumphal arches, baths, and other smaller building projects.[1] During Emperor Hadrian’s reign, he was banished and then executed around 130 CE.


  1. He is sometimes given credit for redesigning the imperial residence as well as the Pantheon, but clear evidence is lacking. For a nice post on Apollodorus’s works, see Apollodorus of Damascus: Architect of Empire.  ↩