Instruction on the Fortification of Cities

...[two] feet thick original: "nhig schuch" - likely "zwey-und-zwanzig" or similar from the previous page, indicating thickness., and that they should be walled into the buttresses behind. Also, the top of the wall should be finished completely flat, so that all shots bounce off it and cannot take hold, as previously mentioned. Thus is this building prepared; thereafter one should take away the corner z. with a small circular line.

But the wall of the breastwork breastwork: a low protective wall or parapet, in front of the guns between the merlons merlons: the solid upright parts of a battlement, should be made three feet high, so that it reaches a man approximately to the waist. This breastwork should also be shaped on the outside with a circular line or set off with a straight line to facilitate the bouncing Dürer uses the term "prellen" to describe the deflection of incoming projectiles. of shots. As I have indicated in the flat ground plans regarding the embrasures original: "schießlöchern," referring to the openings through which guns are fired., the walls of the breastwork between the merlons should be three feet thick; however, they must have a support at the back for the sake of the screen above the guns original: "büchsen," a general term for firearms or cannons here., so that it rests on the wall at the front. Therefore, by necessity, the wall must be nearly four feet thick at the bottom.

But before I go further, note how the screen should be made. First, take strong timber beams, twenty feet long—or as needed, longer or shorter—and make them rounded at the top. These are laid side by side to form a screen, yet in such a way that none touches the other, and each timber is independently movable. They should be arranged so that they fill the width of the merlons side by side, yet they should touch nowhere on any side, so that they stand completely free. One should lay them with the heavy part at the front in the ledge of the breastwork, so that when they snap upward they do not strike the wall; this is done so that as soon as one or more is hit and touched, it may quickly snap up on its balance and move.

Therefore, make the screen so that it can easily move upward either all together or each timber individually. Also, lay the screen-timbers a little lower than the breastwork is high, so that the shots first deflect off the ledge of the wall where they strike, and only then bounce against the screen; in this way, the screen suffers less damage.

Afterward, construct the screen thus: lay a strong round beam, reinforced with iron in the necessary places, transversely across between the merlons, at such a height that one does not hit one's head. Reinforce the screen-timbers with iron where they lie on the roller, and secure them with iron rings that rotate as soon as they are touched; these should also be lubricated with oil when used. Many kinds of these mechanisms are made; whichever works easiest is the best. Yet these things should be made in such a way that they cannot be torn away upon impact. Also, make a strong support behind them, as high as the front beam on which the screen lies, onto which the timbers strike down after bouncing, so they hit no one and do no harm. One may also make this screen so that it can be moved back and forth as desired. One can also use similar screens at the narrow embrasures with hand-thick planks joined together narrowly. Therefore, whoever makes these things correctly will protect themselves from much harm. Such protection is also used on open bastions where no merlons are built.

One may also make high steps behind the merlons so that one can shoot over the merlons with light artillery, arquebuses original: "hacken," referring to the 'Hakenbüchse' or hook-gun, a heavy early firearm., and handguns. Afterward, make the side and rear merlons uniform with the front ones, with the buttress and all things according to the specified wall thicknesses; and thus the upper part is finished.

But since necessity requires that flanking defenses and other lower works also be made below in the bastions, I will now write of those; for although the completely solid bastions—which have no defense other than at the top—serve well for long range, as soon as the enemy begins to entrench original: "schanken," referring to the construction of siege-works or trenches. or enters the ditch, the aforementioned bastions are not only of no more use, but a noticeable disadvantage, since no other flanking fire original: "streichwer," defenses designed to fire along the face of a wall. can be used in front of the same bastion. So that these may also serve for defense at the bottom, they may be made thus: first, the entrance on the ground at the very front, between the two round walls; it may be made wide; this passage shall lead to the embrasures of the flanking defenses?...