Tag: Wind diagram

Another Byzantine Wind Diagram

A 16th-century copy of a Byzantine wind diagram from BN Grec 2493, fol. 165v.

This Byzantine wind diagram, also titled “Diagram about thunder, storms, rainstorms, and earthquakes,” closely resembles the previous Byzantine Wind Diagram. Both come from latter 16th-century manuscripts. This particular copy was never finished—the elements are missing from the center of the diagram, the “παναχῆ” is also missing in this copy.[1] Once again, we see the aspects in the inner circle, the second square is meteorological phenomena, the 12 winds, the signs of the zodiac, south and north poles, and the captions indicating from the right and left parts of the cosmos.

As with the other codex, Royal MS 16 C XII, this codex (BN Grec 2493) contains three texts on the astrolabe—the catalog entry identifies them as Philoponus’s, an anonymous text,[2] and Gregoras’s along with scholia on that last work—and a variety of anonymous astronomical diagrams. The codex also includes texts by Theon of Alexandria.


  1. The image is b&w, so I can’t tell what color inks are used, but the division of inks between the different words also resembles that used in the other diagram. That is, the title, the caption along the perimeter, the poles, the signs of the zodiac, and the four aspects appear to be in a different (red?) ink.  ↩

  2. I suspect this is the text typically attributed to Ammonius, but I haven’t had the time to confirm that suspicion.  ↩

Byzantine Wind Diagram

A 16th-century copy of a Byzantine wind diagram from Royal MS 16 C XII, fol. 49r.

This diagram, titled “Diagram about thunder, storms, rainstorms, and earthquakes,” seems to be a type of wind diagram, which arranged the terrestrial elements, planetary aspects, meteorological phenomena, and winds, signs of the zodiac, and the cardinal directions. Starting from the center we see the four elements—earth, water, air, fire—surrounded by the common planetary aspects. The first square is labeled παναχῆ, “everywhere,” then meteorological phenomena, e.g., lightning, thunder, earthquakes, hail, storms, then the 12 winds, then the signs of the zodiac. The very top of the diagram is labeled “south pole;” the bottom is labeled “north pole.” In red across the top half (starting at the 9 o’clock position) is “From the right (δεξιων) parts of the cosmos;” across the bottom half (starting at the 3 o’clock position) is “From the left parts of the cosmos.”

These diagrams have received little attention, which has (predictably) focused on the Latin tradition.[1] Such diagrams appear regularly in Byzantine astronomical manuscripts.

This diagram is part of a collection of astronomical/cosmological diagrams in Royal MS 16 C XII, a later 16th-century manuscript first owned by Isaac Casaubon, the brilliant classical scholar and historian.[2] Other texts in the codex include the trio of texts on the astrolabe—Philoponus’, Ammonius’, and Gregoras’[3]—as well as a printed text on the astrolabe by Nikolaus Sophianos.


  1. See B. Obrist, “Wind Diagrams and Medieval Cosmology,” Speculum 72(1997): 33–84 (JSTOR’s paywall will likely exclude you, sorry).  ↩

  2. See Hos Advent Calendar 1 for another diagram from this codex.  ↩

  3. See HoS Advent Calendar 3 for another codex with that trio of texts.  ↩