A petard is a small bomb used for blowing up gates and walls when breaching fortifications, originally invented in France in 1579.
[1] A typical petard was a conical or rectangular metal device containing 5–6 pounds (2–3 kg) of gunpowder, with a slow match for a fuse.
Pétard comes from the Middle French péter, to fart, from the root pet, expulsion of intestinal gas, derived from the Latin peditus, past participle of pedere, to break wind.
This was attached to a wall or gate using hooks and rings, the fuse lit and, if successful, the resulting explosive force, concentrated at the target point, would blow a hole in the obstruction, allowing assault troops to enter.
Maltese petards are made by common people without formal education in chemistry, as an exercise in traditional handiwork.