During the Civil War, bombs and other explosives were called torpedoes. This is a bomb made to look like a piece of coal. A hollow container was filled with gunpowder and coated with coal dust. The bomb could be mixed in with real coal and shoveled into the firebox of a ship or train. Secret agents in the Confederacy used these to attack Union transportation.
This resource is part of the A State Divided: Exploring the Civil War Through Images collection.