It was used on the Delaware River as a drift mine .
It was a watertight keg filled with gunpowder that was floated toward the enemy , detonated by a sparking mechanism if it struck a ship .
keg was used on the Delaware River as a drift mine .
It was a watertight keg filled with gunpowder that was floated toward the enemy , detonated by a sparking mechanism if it struck a ship .