P - a m - b - f c n. A way to measure heights and widths and distances without moving one's feet. Place a perfect square on the ground, as appears above; then set your eye over the angle m and look toward the foot of the tower whose distance you wish to know, and as many times as b a enters into a c, so many times does m n enter into n f. And if you wish to know, without moving yourself or your square, the true height of the tower, do thus. Set your eye at the angle n and look at the summit of the tower p, and as many times as b c enters into c n, so many times does p f enter into f n; and knowing, by the first measurement, the true distance that lies between f n, you will be able to know how far the tower fits within it - that is, if b a enters 3 times into a m, so m n enters 3 times into n f, and if m n is one braccio distant, n f will be 3 braccia; and knowing this, you will then be able to know whether b c enters twice into c n, so p f enters twice into f n. Now you know by the first reasoning that f n is 3 braccia, and if p f enters twice into these 3 braccia, it comes to be exactly one braccio and a half. And it is a just and good rule.

Let these logs be bound together and woven with slender iron chains linked one to another. A method how, against ships, one should with a trebuchet throw a great quantity of burning logs together with pitch - or else stones, or bombard powder mixed with straw and vinegar.