Fire-arms may be defined as vessels—of whatever form— used in the propulsion of shot, shell, or bullets, to a greater or less distance, by the action of gunpowder exploded within them. The prevalent notion that gunpowder was the invention of Friar Bacon, and that cannon were first used by Edward III. of England, must be at once discarded. It is certain that gunpowder differed in no conspicuous degree from the Greek fire of the Byzantine emperors, nor from the terrestrial thwuler of the Asian Countries , where it had been known for many centuries before the chivalry of Europe began to fall beneath its leveling power.