# Mathematical Treasure: An Illustrated Commercial Arithmetic

Author(s):
Frank J. Swetz (The Pennsylvania State University)

Libro di Conti di me (My Account Book, 1686, Plimpton MS 235), a commercial arithmetic book, written and illustrated by the Venetian Antonio Venturini, appears to be a fancifully rendered demonstration of an individual’s mathematical knowledge and artistic talent. Most probably, it was drawn and written as a showpiece. The words “scuola Garatti” (“Garatti’s school”) appear at the top of the title page and at the bottom of the second image below (lefthand page), and probably indicate the writer’s teacher of commercial arithmetic rather than his teacher of art.

A bucolic scene adorns the dedication page, which bears the date 1686. The opposite page contains an impressive sum where each addend is a string of digits composed of the first nine counting numbers in their correct order, with the sequences repeated. The author’s intent remains a mystery, as does the creature below, guarding the page. Is it a winged griffin?

A man shakes fruit from a tree and three magic squares float through the scene.

Sea creatures rest on a bed of addition examples.

Stags gather amid a field of computations.

Pig-like elephants inspect a palm tree while, on the opposite page, a fish gazes up at the division problem 42 ÷ 3 ½ = 12. At this point in European history, elephants were exotic and mysterious creatures. Certainly, neither the author nor artist had ever seen an elephant.

A rider falls from his horse while around him the “Rule of Simple Composition” is being explained and demonstrated.

At the end of the book, the inscription within the cartouche reminds the reader that Antonio Venturini was the author.

The images above have been obtained through the kind cooperation of the Rare Book and Manuscript Library of the Columbia University Libraries. These and more images may be accessed via Digital Scriptorium, a digital collection of medieval and early Renaissance manuscripts made available by a consortium of cooperating university libraries headed by the University of California, Berkeley.

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: An Illustrated Commercial Arithmetic," Convergence (June 2018)