We here see the effect produced by rams, much in the way it is proposed to employ them in modern warfare. There will, however, be this difference in a naval battle of the future, that both sides will be provided with these formidable implements of warfare. Before Richard reached Acre a fierce naval engagement had taken place between the besiegers and the besieged. The latter came out of port with their galleys two and two, preserving a similar array in their advance. The Crusaders prepared to receive them, moving to a distance, so that they should not be denied free egress. The Crusaders then disposed their ships in a curved line, so that if the enemy attempted to break through they might be enclosed and defeated. In the upper tiers the shields interlaced were placed circularly, and the rowers sat close together, that those above might have freer scope. The sea being perfectly calm, no impediment was offered to the blows of the warriors or the strokes of the rowers; advancing nearer to each other, the trumpets sounded on both sides, and mingled their dread clangour. First, they contended with missiles, but the Crusaders more earnestly plied their oars, and pierced the enemy's ships with the beaks of their own. Soon the battle became general; the oars became entangled, and the combatants fought hand to hand. There was one English galley which, through the rashness of the crew, got close alongside an enemy, who set her in flames with their Greek fire. The Saracens on this rushing in at all parts, the rowers leaped into the sea, but a few soldiers remained through desperation. Those few overcame the many, and retook their half-burned ship. The weapons used were swords, axes lances, arrows, and other missiles, as well as engines for casting large stones; and both Saracens and Christians employed that burning oil commonly called the Greek fire, which is said to consume both flint and iron. It was the invention of the seventh century, and was long used with terrific effect by the Greeks, who called it the liquid fire. It is supposed to have been composed of naphtha, pitch, and sulphur, with other ingredients. It was propelled in a fluid state through brazen tubes from the prows of vessels and from fortifications, with as much facility as water is now thrown from the fire-engine; igniting the moment it was exposed to the air, when it became a continuous stream of fire, carrying with it torture and destruction. Water increased its power, and it could only be extinguished by vinegar or sand; while, in addition to its other horrors, it emitted a stifling smoke, loud noise, and disgusting stench. Tow dipped in it was fastened to the heads of arrows, which thus became carriers of unquenchable flame. It was kept in jars or large bottles. It was probably introduced into England before the time of Richard the First, for in 1195 a payment was made by the king for carrying Greek fire and other implements from London to Nottingham.