Paraphrasing Capo Ferro: Plate 42, Rotella shield
Posted by Janka
42 down, one more to go!
Here we discuss the use of a shield. He mentions bucklers in the text as something that are used, but does not discuss them; I assume this is because all small items in the left hand are in the end sort of equal.
His point here seems to be that it is unsafe to parry or stringere with the heavy rotella because 1) it is heavy and so slow to come back, and 2) it can block your line of sight, but that the shield is best used by first parrying with the sword and then using the shield to control the enemy's sword that is already off the line.
I will now discuss the use of shield in the case that the adversary also has one.
Sometimes we end up in situations where one party of the fight is less versed in the use of the weapons involved. The rotella is a most dangerous weapon to use when you have no experience about it, so I will give some advice about it here.
You should hold the rotella on your left arm in a sort of "curved" manner, so that it faces somewhat but not completely to your left side. It must be to the side enough so as not to block your sight of the enemy at all.
Let's say he is in a guard with his point in line ("guardia stretta"). Then you must first stringere him, inside or outside depending on his guard. Once you have done this, advance on the left foot, hit his sword (that is already stringered) with the rotella, and strike him vigorously in terza, with a rising thrust.
Let's say then that he is in some guard with his point off the line ("guardia larga").(1)
Say he cuts you to the leg, on either side. In this case, you must parry with a false edge cut and then respond with a cut to his leg of your own.
If he cuts or thrusts you in the face or chest, you can parry it with the rotella, but it's not really clever to do so(2).
This is because the rotella is quite heavy, unlike a buckler, so it is not very quick, and thus you must be careful not to parry feints with it.
In the figure, the person labeled E has started with a feint to the outside of F's rotella. When F raises his rotella to parry, it will block his vision, giving E time to go around it and strike him in the base of his body without the movement of her sword being seen.
F would have been much safer first parrying E's sword with his own, and then advancing with the left foot, striking the already parried sword with the rotella, and striking E with a rising cut in terza.
(1) If he is, it is likely he is preparing to cut.
(2) I do some heavy reordering of sentences here, but as this it not being clever seems to be the point he is arriving to, I thought I might as well state so to begin with.

