The artillery shell was in use by the 15th century, at first as a simple container for metal or stone
shot, which was dispersed by the bursting of the container after leaving the gun. Explosive shells came into use in the 16th century or perhaps even earlier. These were hollow cast-iron balls filled with gunpowder and called bombs. A crude
fuse was employed, consisting of a short tube, filled with a slow-burning powder, driven into a hole through the wall of the bomb. Until the 18th century such shells were used only in high-angle fire (
e.g., in mortars) and confined almost entirely to land warfare. In the 19th century, shells were adopted for direct-fire artillery, notably in the form of
shrapnel.