Another launch then approached a large cask floating with one end out of the water, to represent a boat.  An officer stood up with a little ball of gun-cotton in his hand, smaller than an orange, to which was attached a thin line of what is called lightning cotton, the other end being fastened to a pistol.  As the launch glided on he threw the ball into the cask.  The boat moved away as rapidly as possible, when the pistol being fired, in an instant the cask was blown to atoms.  What a fearful effect would have been produced had the innocent-looking little ball been thrown into a boat full of men instead of into a cask!