An 18th century hand grenade was normally a ball made of iron, ceramic or thick glass and filled with black powder, nails and scatter were sometimes added to the powder in order to increase the number of fragments after the explosion. It had a hole (possibly with a neck) in which a fuse consisting of slowmatch going through a plug. In case of a lack of regulary manufactured grenades improvised grenades could be easily fabricated aboard a ship, by filling black powder or gunpowder into empty coconuts or reinforced gourds. However such grenades were less effective because the improvised hull easily broke when the grenade fell on the ground. Blackbeard had developed a new type of grenades, he filled empty bottles with gunpowder, scatter and small pieces of iron or lead.