1 The Author


Guidobaldo Marchese del Monte1 was born on 11 January 1545 in Pesaro in the territories of the duke of Urbino.2 His father Ranieri Marchese del Monte was a soldier and author of two books on military architecture. He was honored with the title Marchese del Monte by Duke Guidobaldo II of Urbino3. Ranieri's son Guidobaldo inherited the title and became heir to the family estate of Montebaroccio. 

Guidobaldo studied mathematics at the University of Padua in 1564. The military expertise he gained from his father encouraged him to serve for some time in the army and to take part in the unsuccessful campaign of the Holy Roman Emperor Maximilian II4 against the Turks from 1566 to 1568 in Hungary. 

Guidobaldo left the army and returned to Montebaroccio. In Urbino, as a private disciple he joined the circle of Federico Commandino5, an important translator of ancient writings on mathematics and mechanics, including Euclid's Elements.6 Guidobaldo became a friend of Bernardino Baldi7, a disciple of Commandino. Baldi became a versatile scholar and and poet who published numerous works and translations, among them notably a commented edition of the Aristotelian Problemata mechanica and a Cronica de matematici containing biographies of more than 200 mathematicians.8 

In 1577 Guidobaldo published his first book, the Mechanicorum liber9, which is reprinted here in a facsimile edition. The book is a comprehensive treatise on mechanics dealing with the five simple machines, the lever, the pulley, the wheel on an axle, the wedge, and the screw, their properties being in turn derived from the workings of the balance and lever. The idea that every mechanism can be reduced to these five simple machines goes back to Heron of Alexandria10 and has been transmitted to the early modern period by Pappus11, while the foundational role of balance and lever goes back to the Problemata mechanica12 ascribed to Aristotle.13 In 1581, the book was translated into the Italian vernacular14 by Filippo Pigafetta15. 

As a military man Guidobaldo was appointed in 1588 visitor general of the fortresses and cities of the grand duke of Tuscany. He visited Tuscany in the Spring of 1589.16 In the later part of his life Guidobaldo pursued scientific studies and made scientific instruments at the family castle in Montebaroccio. He published further works on geometry (Planispheriorum universalium theorica17), on the center of gravity (In duos Archimedis aequeponderantium libros paraphrasis(18) and on perspective (Perspectiva19). Further books were published posthumously (Problemata astronomica20 and Cochlea21). Several minor works remained unpublished and are known only from correspondence. 

It is known from the exchange of letters that Guidobaldo was in close scholarly contact with many of his contemporary scholars. Historically most significant was his encounter with Galileo22. Their first contact23 goes back to the year 1588. Galileo sent Guidobaldo a proof of a theorem on the center of gravity of parabolic solids, a subject that Guidobaldo himself was working on at that time. That they remained in close scholarly contact is documented several times in a notebook of Guidobaldo24. In the meantime, Guidobaldo as an interlocutor and patron furthered the young Galileo, in particular by securing appointments for him first in Pisa and then in Padua. When Galileo visited Guidobaldo in 1592 on his way to Padua they performed an experiment together on trajectories on an inclined plane which triggered Galileo's work on moving bodies and finally his new science of motion. 

The encounter with Guidobaldo not only influenced Galileo's theoretical work, it also led to a practical turn in his life: like Guidobaldo Galileo became an engineer-scientist.25 He opened his own workshop, taught and wrote treatises on practical matters. In particular he wrote a treatise on mechanics26 following the model of Guidobaldo's Mechanicorum liber reprinted here. Guidobaldo del Monte died in Montebaroccio in 1607. 



Guidobaldo del Monte, 1545-1607; often formerly referred to as Guido Ubaldo.


For the following short biography, see Rose Rose 2008 and Gamba and Andersen 2008. For extensive discussions of Guidobaldo's science and historical context, see Gamba and Montebelli 1988, Biagioli 1990, Bertoloni Meli 1992, Gamba 1998, Micheli 1992), Henninger-Voss 2000, Bertoloni Meli 2006, Bertoloni Meli 2006 and Bertoloni Meli and Gamba 2011.


Guidobaldo II della Rovere, 1514-1574, was duke of Urbino from 1538 until his death.


Maximilian II, 1527-1576, was emperor of the Holy Roman Empire from 1564 until his death.


Federico Commandino, 1509-1575.


See, in particular, Bertoloni Meli and Gamba 2011; Ptolemaeus 1562; Perga 1566; Euclid 1572; Samos 1572; Alexandria 1588.


Bernardino Baldi, 1553-1617.


See Alexandria 1588.


Monte 1577.


Heron (or Hero) of Alexandria, ca. 10–70 CE.


Pappus of Alexandria, ca. 290–350 CE.


Aristotle 1980.


The attribution of the treatise to Aristotle, 384–322 BCE, has long been a matter of controversial discussion. See the recent contribution by Krafft 1970, 13-20.


Monte 1581.


Filippo Pigafetta, 1533-1604.


Menchetti 2011.


Monte 1579.


Monte 1588.


Monte 1600.


Monte 1609.


Monte 1615.


Galileo Galileo, 1564-1642.


On the cooperation between Guidobaldo and Galileo, in particular on its role for the discovery of the law of fall and its dating, see Renn et.al. 2000.


Monte first entry ca. 1587. See the discussion in Renn et.al. 2000.


See Valleriani 2010.


This treatise, completed in 1602, was originally only copied and sold in the context of his teaching activities. After his condemnation, it was published in French translation by Marin Mersenne Galilei 1634.


Guidobaldo del Monte's Mechanicorum Liber

Table of Contents

Part 1: On this Book

1 The Author

2 The Context

3 The Book

4 Online Sources


Facsimile Reproduction

This publication is licensed under a Creative Commons Attribution-Non Commercial-Share Alike 3.0 Germany (cc by-nc-sa 3.0) Licence.