Heb. hishalon i.e., "invention" (as in Ecclesiastes 7:29) contrivances indicating ingenuity. In 2 Chronicles 26:15 it refers to inventions for the purpose of propelling missiles from the walls of a town, such as stones (the Roman balista) and arrows (the catapulta).
Heb. mechi kobollo, i.e., the beating of that which is in front a battering-ram (Ezekiel 26:9), the use of which was common among the Egyptians and the Assyrians. Such an engine is mentioned in the reign of David (2 Samuel 20:15).