Note 6 — WAR AND DIPLOMACY IN SHAKESPEARE.
Reading edition
It may be irreverent to doubt whether Shakespeare knew or regarded the difference between a petard and a mine; yet it is certain that a petard was not fitted to hoist anything, but was a special contrivance for blowing in gates and the like. It was a novelty in the third quarter of the sixteenth century (Littré, s.v.). Drayton understood its use, but by a slip as bad as any of Shakespeare’s brought ‘the Engineer providing the Petar, to breake the strong Percullice’ into Henry V.’s war: ‘The Battaile of Agincourt,’ ed. Garnett, p. 22.