The drawings of strange animals in the margin of a precious medieval manuscript have been revealed as doodles by children, presumably bored by the dense Latin text.

The book, now in the library of the University of Pennsylvania, was written by a 14th-century Franciscan monk in Naples, and includes astronomy and astrology tables, sermons, columns of biblical dates and tables for working out any day of the week between 1204 and 1512 – all thoroughly dull to the children into whose hands the manuscript fell a few centuries later.

Deborah Thorpe, a research fellow at the University of York, whose findings are published in the Cogent Arts and Humanities journal, believes that the lively drawings in the margins are the work of at least two children.

Several pages have been embellished with ink drawings of spaceman-like creatures with spiky horns, big heads and long, spindly legs, which may have been intended as demons.

There is also a more sophisticated drawing of a cow-like creature Thorpe believes is the work of an older child. Since the cow is tethered to an object resembling a grinning kitchen stool – analysed by a developmental psychologist consulted by Thorpe as a tadpole-like image of a human being typical of a four-year-old’s artistic prowess – she thinks an older and younger child joined forces to create that one.



The drawing of a cow-like creature is thought to have been the work of an older child. Photograph: University of Pennsylvania/PA

Thorpe found the drawings by chance while working through a database of medieval manuscripts online for an unrelated project.

She has researched how the book escaped into the hands of the small vandals from an Italian convent library in 1327, and believes a Dominican friar, Umilis of Gubbio, borrowed the book soon after it was written, but did not returned it despite paying a hefty deposit of one florin. Thorpe notes that the name of the original scribe was destroyed, presumably by a later owner trying to conceal incriminating evidence.

The drawings, Thorpe says, are evidence of the books being kept and read where children were near, in a private collection in the 15th or 16th century; there are no costume or architectural details in the drawings to help date them. She exonerates the children of mindless vandalism: they may have drawn on a precious book, she notes, presumably when their grown up guardians’ backs were turned, but they stuck to the margins, carefully avoiding damaging the text, boring though it may have been for them.

The problem of children and books was well known to book collectors and librarians, Thorpe says. The author of one 16th-century treatise on caring for books so they would last “at least 200 years” finished his text, but returned to it to add an important extra rule: “Eighth, one should not let children learn from any books that one wants to preserve. Because whatever comes into their hands, as we see, it either stays there or it is ruined.”