I n the early 17th century, Galileo Galilei enjoyed a celebrity status at the University of Padua, where he published his first work in 1606. But, when an eager rival accused him of plagiarism shortly theafter, Galileo’s integrity was called into question. In this First Look video, discover how the father of modern physics restored his good name and quashed claims of illegitimacy. Sotheby’s sale of The Erwin Tomash Library offers the rare opportunity to own the three seminal texts at the heart of this historic controversy (18–19 September | London).
In 1597 Galileo designed and built his ‘compasso geometrico et militare’. The compasso made it possible to perform complex operations, both mathematical and geometric. Using two equal-length rulers on a hinged disk the instrument was able to calculate the ballistics of artillery shots and redraw maps with different scales as well as calculate exchange and interest rates. The compasso physically looked like something between a slide rule and a protractor.
In 1606 the instrument had undergone several modifications and the corresponding manual, which had previously been manuscript, was transitioned to print. Lot 197 is the first edition (second issue) of this manual - Galileo’s first published work. The reason for this transition to print was guided not only by reasons of economy but also Galileo’s decision to assert his rights as inventor of the instrument.
The next year, 1607, Baldassare Capra published Galileo’s Le Operazioni del compasso geometrico et militare (Lot 101 is the rare first edition in Latin). In this work, Capra accuses Galileo of having copied his instrument from a pre-existing model, and otherwise belittles him. Outraged, Galileo appealed to the University of Padua authorities, demanding the immediate seizure and destruction of Capra’s book. After investigation, the rectors agreed. Of the total edition of 483 copies, 453 were impounded, leaving a mere 30 in existence.
Galileo then wrote Difesa to attack rival Capra and refute his accusation of plagiarism. Although Galileo discusses the instrument’s applications and how it is made, the majority of the text is a presentation of his grievances against Capra. Lot 198, a first edition of this work, is no doubt one of the highlights of this library. Only 40 copies of Difesa are known to exist, of which only about ten have been seen on the market for the past 100 years. This edition is a presentation copy and one of only 8 copies that are known to contain a dedicatory inscription in Galileo’s hand.