Edited sentence: Even the old Japanese paintings show the Japanese samurais defending themselves against bombs and rockets hurled by the invaders.Half of their army drowned in the sea.It was when the Mongols, after invading China, went on to subdue Japan, their ships sunk due to typhoon.Similar, pots with ignited fuses had been shot from mechanical artillery against the Japanese defenders.The recent discovery of the boat revealed that the Mongols were carrying gunpowder in ceramic pots