A few days ago, when discussing the way that the Sagittarius crossbowman appears in similar fifteenth century manuscripts, I wrote that it was clear to me “that we are looking at a family of manuscripts with many similar features“, and that I suspected “the real historical heavy lifting – building a complete list of these fifteenth century manuscripts, and then deriving a cladistic tree linking them all together – must have been done already“.
With some initial help from Jürgen W. in Cambridge (thank you very much!), and then a little further assistance from (the now-retired) Professor Francis B. Brévart himself, I believe I now have the basic literature framework in place that forms the backdrop to what we seem to be looking at. It will take a lot more work to fill out the picture more satisfactorily, but what follows should bring anyone interested in what I’m writing about up to speed.
There are a large number of (largely fifteenth century) manuscripts and incunabula that cover broadly the same set of material: tables of Saints days, tables for calculating the position of the moon over its 19-year Metonic cycle, tables showing unlucky days (e.g. when not to undergo bloodletting, cupping, etc), lucky days (e.g. “guldin zal”), days to take baths, days to avoid hot baths, etc. Some also have extensive sections on the signs of the zodiac and the planets: many are bound along with similar documents. As a genre, this is almost exclusively German, though a handful of Old French versions have survived.
The first person to try to properly catalogue these documents was Ernst Zinner, in his (1925) “Verzeichnis der astronomischen Handschriften des deutschen Kulturgebietes” (though with three later addenda in 1952, 1962, 1964). Their contents were often copied one from the other (though with frequent differences), but as I understand it Zinner was more interested in collating the raw bibliographical data rather than trying to offer a cladistic synthesis of them all.
The specific name Zinner gave to these fifteenth century texts was “Volkskalender“, as a loose analogy to a separate series of much later (mainly 18th century) calendars. Despite the many substantial differences between the two series of documents (and the protests from other historians, who rightly point out that these calendars were necessarily expensive, and so probably had little to do with ordinary volks at all), the name has stuck.
All the same, the bibliographic references for individual documents may well refer to them as “Iatromathematisches Hausbuch”, or “Hausbuch”, or any number of different names. Brévart (1996) is fairly scathing about the definitional hole some historians have dug themselves into here: but all that needs to be said is that they’re all essentially talking about the same group.
Brévart’s two families
Professor Francis B. Brévart spent many years looking at these specific manuscripts. From our point of view, his two most significant publications were:
* “The German Volkskalender of the Fifteenth Century” [via JSTOR], in Speculum 63 (1988), pp.312-342.
* “Chronology and Cosmology. A German Volkskalender of the Fifteenth Century,” The Princeton Library Chronicle (1996), pp.225-265.
While Brévart 1988 discusses the contents of the manuscripts and introduces the two main families these fall into, Brévart 1996 includes a substantial list of the manuscripts in the two families. You really need to read both papers to get a clear picture of these manuscripts. Thankfully they combine erudition, attention to detail, and clarity of expression: very highly recommended.
The single document from which all the others ultimately derived was an extended Kalendarium compiled by Johannes Wissbier of Gmund between 1404 and 1405. Brévart refers to the more than thirty manuscripts directly descended from this as his “Volkskalender A” family. However, Brévart 1988 continues:
“During the third decade of the fifteenth century a totally different version of the Volkskalender came into being. In addition to the Kalendarium and the treatises on cosmology, the signs, and the planets found in Wissbier’s work, it included various other texts- for example, on the labors of the months, the four temperaments, phlebotomy, bathing, purging, and the unlucky days.”
This separate set, comprising more than twenty documents, is what Brévart calls the “Volkskalender B” family. This is the family we should be most interested in.
Brévart’s “Volkskalender B” family
Brévart 1996 lists (pp.250-254) twenty-six Volkskalender B documents (though also giving a useful mini-bibliography on each one, which I have not reproduced here):
* Berlin: Staatsbibliothek Ms. germ. 2° 1069 [link]
* Berlin: Staatsbibliothek Ms. germ. 4° 20 [link?]
* Berlin: Staatsbibliothek Hdschr. 319 [link]
* Edinburgh: The Library of the Royal Observatory, Ms. Crawford 4.6. (olim 9.14-5.14) 
* Einsiedeln: Stiftsbibliothek Hs. 297  [link]
* Erlangen: Universitätsbibliothek Cod. B 27 (olim Irm. 1365) [link]
* Frankfurt: Stadt- und Universitätsbibliothek Ms germ, qu. 17 [link]
* Heidelberg: Universitätsbibliothek Cpg 291
* Heidelberg: Universitätsbibliothek Cpg 298 (“and 831” [?])
* Heidelberg: Universitätsbibliothek Cpg 557
* Karlsruhe: Badische Landesbibliothek Cod. 494 (olim Donaüschingen, Fürstlich-Fürstenbergische Hofbibliothek) 
* London: British Library Ms. Add. 17987 [Warburg lo-res photos]  [link]
* London: University College Ms germ. 1  [link] [UCL description]
* Munich: Bayerische Staatsbibliothek Cgm 28 [c.1440] [link]
* Munich: Bayerische Staatsbibliothek Cgm 349 [c.1480] [link]
* Munich: Bayerische Staatsbibliothek Cgm 730 [c.1500] [link]
* Munich: Bayerische Staatsbibliothek Cgm 736 [c.1465] [link]
* Munich: Universitätsbibliothek 2° Cod. ms. 578  [link]
* Nuremberg: Staatsarchiv Hs. 426  [link]
* Prag: Narodni Muzeum Schlossbibliothek Krivoklat Cod. Ie7 (51.996)
* St. Gallen: Stiftsbibliothek Cod. 760
* Tübingen: Evangelisches Stift Msc. 17 
* Vienna: Oesterrichische Nationalbibliothek Cod. 3085
* Wolfenbüttel: Herzog August Bibliothek Cod. 264.5 Extravagantes  [link]
* Würzburg: Universitätsbibliothek Cod. M.p.med.f.5 [c.1450] [link]
* Zurich: Zentralbibliothek Ms. C 54 [c.1465] [link]
It’s possible that there are several more manuscripts in this family that escaped Brévart’s roving eye, e.g. this one as mentioned by René Zandbergen (though Brévart categorises it as a Volkskalender A family member):
The Sagittarius Crossbowman link
Why should anyone be interested in this family of documents? Simply because these contain almost all the roundel images of Sagittarius-the-zodiac-sign where what is normally depicted as an archer is instead depicted as a crossbowman.
Personally, I’m very much convinced by the previously-made suggestion that the crossbowman image in some of these documents was accidentally copied from a roundel of Sagittarius-the-constellation: and so it seems to be a very strong possibility that the Sagittarius crossbowman depicted in the Voynich Manuscript was copied from a member of the Volkskalender B family.
Moving forward, the idea would be to try to work out the relationships between these 26+ documents, and then see how the Voynich Manuscript’s section fits in to that tree. There are bound to be copies missing from the tree, for sure: but it seems to me that just about the surest way we will ever have to understand the Voynich Manuscript’s “zodiac” section is by carefully placing it in the context of Brévart’s “Volkskalender B” family, and seeing what we learn.