Plate

Both fencers bound outside in Third guard; striker transitions hand from Third to First, raising against opponent's blade
Both fencers bound outside in Third guard; striker transitions hand from Third to First, raising against opponent's blade De lo Schermo, overo Scienza d'Arme · Copenhagen, 1606 · Plate 25

Translation

This other figure represents a wound made with the guard of First against Third. Both combatants are in Third on the outside, have brought the swords together, and have begun to press one against the other. The striker turns the hand from Third into First. This guard by its nature tends to wound toward the ground and has its strong underneath. Thus, by raising the hand, the enemy sword comes to remain below, in the place where his own blade is strongest; moreover, in that same raising he has come near the enemy weak, and in the selfsame instant has driven on and wounded, as is seen.

He would have made the same offense with less effort had the wounded man been in Second, because although Second covers that part more, it is much weaker, and so First would have overcome it more easily than this Third. A further cause of this wound is that contesting of the swords. Here one should note how bad it is to resist one who uses force, and how much better it is to yield, indeed to take the sword away; for the sword that wishes to contend with force cannot but make some little drop while the other yields. This gives the adversary a tempo either to wound or to take some advantage over the falling blade, which is much safer and much less fatiguing.

Analysis

Initial guards Both in Third (terza), on the outside (fuori della spada).
Wound Thrust in First (prima).
  1. Both blades are bound outside and begin to press (attaccate le spade insieme, fare forza).
  2. The striker turns the hand from terza to prima (voltata la mano di terza in prima).
  3. Since prima naturally carries the strength low (ha il suo forte di sotto), raising the hand leaves the opponent's blade below in your strongest line.
  4. In the same raising action you approach his weak (avicinato al debile).
  5. In the same instant you push through and wound (in un tempo istesso si è spinto oltre, e ha ferito).

Translation note

Johnson's "naturally tends to hit towards the ground" is too loose. Better: "First naturally strikes low and has its forte underneath."
The Steel Marginalia · HEMA Study Group Notes in the margins. Truth in the bind.