Color illustrations of rocket-propelled cats and birds have recently been found in a 16th century war manual, according to a University of Pennsylvania researcher.

Written by artillery master Franz Helm of Cologne, who likely fought against the Turks during the mid-16th century, the manual on artillery and siege warfare dates to about 1530.

Among fanciful illustrations, the text in German explains the shocking project to put timed explosives onto birds and cats in order to “set fire to a castle or city which you can’t get at otherwise.”

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Called “Buch von den probierten Künsten” (Book of the tested arts) Helm’s treatise circulated widely in manuscript but was not published until 1625. It was rediscovered by Mitch Fraas, a historian and digital humanities expert at the Penn library.

Fraas began researching the war treatise after finding its unusual and disturbing illustrations on the book blog BibliOdyssey.

Among various illustrations of explosive devices, one image appeared particularly odd. ”It showed a cat and a bird propelled by rockets towards a castle,” Fraas said.

Fraas was able to track the images to Helm’s manual, whose print edition is kept in the Penn collection.

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According to Fraas’s translation, in the treatise Helm explained how the poor animals could be used as explosives.

“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,” Fraas said.

Whether the pyrotechnic warfare technique was ever actually employed by Helm, we may never know.

“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,” Fraas said.

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According to the Finnish scholar Pentti Aalto, examples of incendiary-bearing cats and birds are mentioned from a third century B.C. Sanskrit text, as well as in the Russian Primary Chronicle, early Scandinavian sources, and an early modern history of Genghis Khan.

“Just today folks have been emailing me that there are illustrations of early Chinese fire animals out there,” Fraas told Discovery News.

He mentioned a “fire ox” depicted on the “Wu Ching Tsung Yao” (“Collection of the Most Important Military Techniques”), a Chinese military treatise written in 1044 A.D.

Illustration: A cat and a bird are propelled by rockets towards a castle. Credit: UPenn Ms. Codex 109, f137r.