Before the discovery of Greek fire, flaring missiles of some kind had been devised. Frontinus mentions fire-ships, or hulls carrying combustibles and allowed to drift with wind and tide upon the enemy’s ships: stinkpots, to nauseate the enemy, though how the others escaped the smells except by keeping to windward does not appear; and Evelyn adds, “Nay, snake pots, and false colours.” The Greek fire, however, was the most terrible of the weapons employed at that time. By some means by which a fair amount of power was exerted, the liquid was squirted--or vomited, to use one historian’s phrase--through copper pipes upon an enemy’s ship, and as the liquid had the peculiar property of igniting upon exposure to the air and was inextinguishable by water, it was a most formidable engine of destruction. Small vases filled with the liquid and sealed airtight were used as hand grenades and flung at opposing ships and, breaking, set them on fire. Heavy arrows carrying balls of flax soaked in the liquid were used both in land and sea warfare, as also were hand-flung javelins similarly equipped, and the flights of these masses of inextinguishable flames must have been equally demoralising to the combatants against whom they were directed and destructive to the ships and inflammable buildings upon which they fell. This composition is thought to have been invented in the seventh century; the first occasion on which it was employed on an extensive scale was in the great battle between the fleets of Constantine and the Saracens, when the latter, through its agency, lost practically their whole fleet and thirty thousand men killed. After that both sides used Greek fire whenever possible. Up to the introduction of gunpowder and artillery the methods of fighting varied but little. The sea-fights of the Crusades were conducted on the lines which had been recognised as the best for a couple of thousand years or more, viz., ram the enemy and board him. Greek fire added this rule: Burn him also if you can.