Canister Shot from the Waterloo battlefield, 1815

These are balls from a canister shot, a kind of short-range cannon ammunition fired at the Battle of Waterloo. Canister shot - named because these iron balls were packed inside a tin canister for firing - was designed to as a weapon of last resort, used by desperate cannon crew to fire on enemies as they charged at the guns. Like a giant shotgun shell, the canister would explode and fire out these iron balls in a devastating blast.