To the Most Illustrious & Invincible Lord Francesco Maria Feltrense

della Rovere, Most Excellent Duke of Urbino & of Sora,

Count of Montefeltro & of Durante, Lord of Senigallia

& of Pesaro, Prefect of Rome, & Most Worthy

Captain General of the Illustrious

Venetian Senate.

Epistle:

A large square woodcut decorative initial 'H' featuring an intricate interlaced knotwork pattern in a dark block.

WHILE RESIDING IN VERONA
in the year 1531, Most Illustrious Lord
Duke, I was asked by an intimate and
cordial friend of mine—a most skilled bombardierA soldier or officer in charge of aiming and firing artillery. in Castel VecchioThe "Old Castle" in Verona, a significant medieval fortress and military installation.
(a man advanced in years and abundant in many
virtues)—concerning the method of aiming a piece of artillery to the furthest
extent that it can shoot. And although in such an art I had no practical experience (for
in truth, Excellent Duke, I never discharged artillery, arquebusA long-barreled firearm, an early precursor to the musket.,
bombardA large-caliber, muzzle-loading cannon used primarily in sieges., nor gun) nonetheless (desiring to serve my
friend) I promised to give him a definitive answer in short order. And after
I had thoroughly chewed over and pondered such material, I concluded and demonstrated to him
with natural and geometric reasons, how it was necessary for the
mouth of the piece to be elevated in such a way that it looked straight at 45
degrees above the horizon; and that to do such a thing expeditiously, it is
necessary to have a squareA tool for measuring right angles and levels. made of some metal or hard wood that has
enclosed a quadrantAn instrument used to measure angles of elevation, usually consisting of a 90-degree arc. with its plumb lineA weight (lead) suspended from a string used to find a vertical reference line. as appears
below in the drawing; and then by placing a part of the longer leg of that tool
(that is, the part marked b. e.) into the boreThe hollow interior of the barrel of a gun. or mouth of the piece, extended straight
along the bottom of the hollow of the barrel, then raising the front of the said
piece so much that the plumb line h. d. cuts the curved side e. g. f. (of the quadrantoriginal: "quadrā"...