I was puzzled when a friend asked me a few weeks ago if I’d seen the “rocket cat” illustrated in a Penn manuscript which had been featured on the book blog BibliOdyssey in November. The image, from what was described as a 1584 “Feuer Buech” manuscript, appeared to show a cat and a bird propelled by rockets towards a castle.
I enthusiastically retweeted the image and began trying to figure out just what was going on in the manuscript . Since then, the “rocket cat” has gone somewhat viral, appearing in the Atlantic, BoingBoing, and elsewhere. Given the illustration’s new-found fame I thought it would be worthwhile to provide a bit of context.
The illustration above comes from UPenn Ms. Codex 109 which came to the library as part of the Edgar Fahs Smith history of chemistry collection. This manuscript is one of several at Penn dealing with the early history of gunpowder, artillery, and explosives. Based on the title I assumed it was one of the many manuscript copies of the famous c.1420 Feuerwerkbuch which provides instructions to artillery masters on how to construct weapons, aim guns, and manufacture various explosives . So where does the explosive cat fit in? I looked through both the printed German text of the Feuerwerkbuch and the English translation in vain – “explosive fire balls” and “fire arrows” are covered in the text but no fire cats. Along the way I also discovered that another of Penn’s manuscripts had an almost identical illustration:
In this case, a c.1590 “Book of instruction for a cannon master.” Clearly these fiery animals were more than just the fancy of one manuscript illustrator. Further, the text accompanying the illustration in both Codex 109 and LJS 442 did not match anything I could trace in editions of the Feuerwerkbuch. Fortunately, in the torrent of tweets about the rocket cat, one came in citing yet another example of the illustration, this time from a manuscript at the Universitätsbibliothek Heidelberg.
Heidelberg has cataloged their manuscript as the “Buch von den probierten Künsten” of Franz Helm. Though drawing on the Feuerwerkbuch, this text dates from a century later (c. 1530) and includes large new sections on siege warfare and different types of explosive weapons. In fact, the Penn collection includes an identified copy of Helm’s treatise, though unillustrated (LJS 254). Thanks to a recent critical edition of the work I was able to confirm that the text of both LJS 442 and Codex 109 were indeed from the Buch von den probierten Künsten .
Franz Helm of Cologne was an artillery master in the service of various German princes and likely served in campaigns against Turkish forces during the mid-16th century. His treatise circulated widely in manuscript but was not published until 1625. Remarkably, that print edition of his work (a copy of which is here at Penn) also includes an image of the cat and bird:
So what does Helm actually say about these explosive animals? Are there rockets involved at all? In the text accompanying the images is a section entitled “To set fire to a castle or city which you can’t get at otherwise” . This section details how to use doves and cats loaded with flammable devices to set fire to enemy positions. On cats the text paints a grisly picture of attaching lit sacks of incendiaries onto the animals to have them return to their homes and set fire to them. In my awkward translation:
“Create a small sack like a fire-arrow … if you would like to get at a town or castle, seek to obtain a cat from that place. And bind the sack to the back of the cat, ignite it, let it glow well and thereafter let the cat go, so it runs to the nearest castle or town, and out of fear it thinks to hide itself where it ends up in barn hay or straw it will be ignited.” 
There’s no way to know if Helm himself ever employed this method of pyrotechnic warfare but strangely enough the idea of using cats and birds in just this way appears in historical texts from many disparate regions of the world. In a magisterial article on the subject, the Finnish scholar Pentti Aalto cites examples of incendiary-bearing cats and birds from a 3rd c. BCE Sanskrit text, the Russian Primary Chronicle, early Scandinavian sources, and an early modern history of Genghis Khan .
Though not actually depicting ‘rockets’ of any kind, these images help demonstrate the enormous demand for manuals on gunnery and explosives in the early modern period as well as the robust world of 16th c. manuscript copying and the persistence of illustrations and manuscript forms into print.
[UPDATE: Alexis Madrigal does a great job summarizing this piece over at the Atlantic! Thanks!]
 For a storified account of these tweets see http://storify.com/MitchFraas/cat-with-jetpack
 For a facsimile of the first printed edition of the Feuerwerkbuch (Augsburg, 1529) along with a transcription in modern German see Hassenstein, Das Feuerwerkbuch von 1420, (Munich, 1941). For an English translation of the manuscript text of the Feuerwerkbuch with notes see Gerald W. Kramer and Klaus Leibnitz, “The Firework Book: Gunpowder in Medieval Germany,” The Journal of the Arms & Armour Society 17.1 (March 2001), p. 1-88.
 Many thanks to Brigitte Burris for her help with the text – all errors are mine of course! The Heidelberg manuscript (the most legible) reads: “Mach ein klein secklein wie zu einem fewer pfeyl…tracht ob du mogest Bekhomen im schloss oder statt, ein katzen so darein gehörig, unnd bind das secklein der katzen auff den Rucke, zunde es an lass wol gluen, unnd darnach die katzen Lauffen, So tracht sie dennegsten, dem schloss oder statt zw, und vor forcht gedenckt sie sich zuuerfriechenn, wo sie in scheweren hew oder stroe findt, wurtt es von ir angezundet.” The printed text from the 1625 edition (p.49) is pictured below:
 Pentii Aalto, “Kautilya on Siegecraft,” Annales Academiae Scientiarum Fennicae (Series B) 223 (1983), pp. 11-21. The extract from the Russian Primary Chronicle describing the actions of Olga of Kiev (c.945 CE) is particularly striking:
“Olga requested three pigeons and three sparrows from each household. Upon their receipt, her men attached rags dipped in sulphur to the feet of each bird. When the birds returned to their nests, they lit the city on fire and the Derevlians perished in their homes.Olga’s vengeance was now complete.” The Russian Primary chronicle : Laurentian text, (Mediaeval Academy of America,1953), p.81.