Formerly 359 v.b; old numbering 198 (in pencil); 125-175 x 120-180 mm; paper tinted blue. Clark-Pedretti (I 6⁹ hold that the cut-off upper corner may be f. 12432 at Windsor. The upper drawing repeats a drawing of f. 38. Here it is stated that the base, in the form of an irregular truncated pyramid, must enter a hole and should therefore serve to anchor, by means of the hook, some heavy piece of furniture. At the left a conical screw recalls that of f. 156, which serves to cut the threads of nut-screws. Lower down, a winch with a wheel-flywheel. At the right, more complex gear-trains.

f - b d - a c g. Three and a half braccia high, two braccia wide, so that two men meeting each other can give way to one another. A foot, or else an elbow.

I run the channel f g on the inside of the ironwork, so that the water does not penetrate past the first outer wall, but comes to pass through the vents that let the water into the vault. For if I made it flush with the outer wall, it would then be as if the earth were not between the two walls, because that earth would come to be perforated in those places where such waters enter the vault. Let the pump be made for emptying the flooded vault. Let the oak chest be made at the bottom.

So that the enemy may not find the entrance of the water from outside; and inside, in a b c d, fissures are left between one brick and another, of as much space as is the lime inserted between those bricks, and besides this let spaces be left between one fissure and the next of 6 or 8 bricks. Let the earth be beaten by potters, and be of the fine kind for making jugs; and then well pounded and compacted in the place where it is set. Let the stones be joined with fine, fresh lime with very little sand. Let the fissures inside the vault be somewhat closed at the ends of their lips with thin, weak clay for making jugs, so that they are not seen by those who go back and forth.