Instruction on the Fortification of Cities

Between the two straight rear walls, descend into the corners; there, one should make a landing original: "fleß," a flat platform or landing between flights of stairs five feet feet: "schuch," literally "shoes," a historical unit of measurement roughly equivalent to a modern foot wide. There, turn the stairs and lead them down along the side walls toward the curved wall. One should break the stairs in the middle and make another landing five feet wide before the next flight of stairs begins below it; this is so that if someone missteps, they do not fall all the way down at once. The steps original: "staffel" should also be made five feet long, as wide as the passage itself, as I will show later in the ground plan illustration. These stairs are to be covered entirely with strong vaults, as described before, and under the arched vaults upon which the stairs rest, one shall fill it all in and not leave it hollow.

But when one goes from the city above to the doors at the rear of the bastion bastion: "pastey," a projecting part of a fortification built at an angle to the line of a wall, allowing defensive fire in several directions, one should make landings three feet wide between the doors and the start of the stairs, so that one may access both passages to the right and left. However, if one wishes to shift the stairs away from the door to allow carts to be driven in, that may also be done. After that, divide the height from the entrance of the door to the top of the bastions with a horizontal line in the middle, and beneath this line, next to the lower stairs leading up from the door, enclose a strong arch two feet thick and seven feet wide from one wall to the other. This should be done so that the high part braces against the outermost wall toward the city and is firmly integrated into the two flanking walls; then wall the arch over the top and level it off.

Next, divide the lower landing where one enters the door between the two flanking walls into five equal fields using four points. Mark the point nearest the flanking wall toward the city with an a. Place one foot of a compass there, and with the other, draw the aforementioned arch beneath the landing. After that, draw the two stairs rising above one another: the lower one from its lowest point by the door up to the corner where the upper landing of the arch and the inner flanking wall meet. Then go back again and make the second staircase like the first, once more upon the arch that has been enclosed; thus it comes to one side, above and next to the lower staircase.

Also, beneath each of the two stairs, make a high and a low arch with a pillar in the middle upon which the stairs are carried; into these openings, one may place various things by hand. And as I show here how the stairs are one above the other and yet side-by-side—so that each has its own free passage back to the start of the other—one must also leave a free passage two feet wide between the stairs. If anyone wishes to have or make a wider passage, they may do so, so that one may go from the top of one staircase to the start of the other without hindrance. Therefore, the buttress arches original: "streb pogen" of the stairs must be shifted if more were to be made. These steps should also be made five feet long; beyond the staircase wall, fill and wall everything up behind it.

If, however, this bastion must stand in a deep circular ditch so that one must ascend from the very bottom, then make three more arches and stairs beneath the topmost ones, shaped exactly like the upper part described, so that one may go up and down in this bastion. Furthermore, lead a light source to the middle of each staircase through round holes in the outermost wall, protected by grates, which can be opened and closed with iron-clad shutters operated by pull-cords.

While the masonry is being built up, the interior filling should also be poured in. Some fill it with earth, but the best filling for such a magnificent building is made with boulders original: "wacken" and broken stones, both large and small, which are the remnants left over when the ashlars ashlars: "quadern," finely dressed, square-cut stones are hewn. These should be packed in very diligently, leaving as little empty space as possible. The stone dust original: "sand" that falls from the hewing of the ashlars should be diligently mixed with lime water and poured over the assembled stones; in time, this filling will become as firm as solid stone. The city wall that meets the bastion on both sides should be a little lower than the platform on the bastion, so that one can fire in all directions as mentioned before; this can be seen in the following illustrations.