The Pneumatics of Hero of Alexandria

of Your Highness, and now by your grace appointed over the fortification of this your City of Ferrara) spend all my time around this structure, and if anything remains for me, let it all be placed in those studies that can show me most fit to serve you. And because last year, 1586, I was oppressed by an infirmity, if not mortal, at least grave and lasting more than three months, while in my convalescence I could not exercise myself in the acts of Practice, I occupied myself with those of Theory, translating into our tongue the Book of Spirituals by HERO, an excellent Mathematician. Having found this work to be excellent, and not wishing to defraud the World, for the benefit of which everyone is born, I have resolved to give it to the Press, so that every mediocre talent might possess in this faculty all that, under the veil of the Greek and Latin tongue, remained hidden from many. And having to bring it to light, I judged it my duty that it should reach the hands of the virtuous, not as my own thing, but as that of Your Highness, for the reason stated above; not being able, while I am made worthy of this grace by you, to operate anything that is not yours. Besides, it would not be fitting that the World should have a work by one of the Mathematical Princes, if not through the means of the grace of a Prince as great as you are, a new Maecenas of the Virtuous. May Your Highness therefore deign to grant me the favor that, without offense to you, I may sign it on the front with your glorious name; because for this effort the Virtuous will owe all their obligation to you alone, and I meanwhile, in the vacations from the fortification, so as not to consume my

time in idleness, will go on reducing to completion my Archimetro a mathematical instrument for measuring, a Mathematical instrument, which is already in good condition, and from which the World will have the Geometrical operations of all the other instruments, as much ancient as modern, come to light until now, in a way so easy and just that it will not be judged that the name of Archimetro was given to it by chance. This work, when it succeeds to the satisfaction of the World, will give me the courage to put the final hand to the Theater of all the sciences and arts, of which there is no doubt that one must be more than moderately instructed, who wishes to attribute to himself the name of Architect, or Engineer, as today it is called. Around this work, for a long time now, I have been laboring for the glory of God, for the benefit of the Studious, and the service of Your Highness, who may meanwhile live happy, and may God grant you the fulfillment of all your desires.

Illustrious Hero’s Spiramina, accept, worthy of the heavenly spirits, generous Duke of the Po.