Looking at an old-time cannon, most people are sure of just one thing: the shot came out of the front end. For that reason these pages are written; people are curious about the fascinating weapon that so prodigiously and powerfully lengthened the warrior's arm. And theirs is a justifiable curiosity, because the gunner and his "art" played a significant role in our history.

THE ANCIENT ENGINES OF WAR

To compare a Roman catapult with a modern trench mortar seems absurd. Yet the only basic difference is the kind of energy that Sends the projectile on its way.

In the dawn of history, war engines were performing the function of artillery (which may be loosely defined as a means of hurling missiles too heavy to be thrown by hand), and with these crude weapons the basic principles of artillery were laid down. The Scriptures record the use of ingenious machines on the walls of Jerusalem eight centuries B. C.—machines that were probably predecessors of the catapult and ballista, getting power from twisted ropes made of hair, hide or sinew. The ballista had horizontal arms like a bow. The arms were set in rope; a cord, fastened to the arms like a bowstring, fired arrows, darts, and stones. Like a modern field gun, the ballista shot low and directly toward the enemy.

FIGURE 1—BALLISTA. Caesar covered his landing in Britain with fire from catapults and ballistas.

The catapult was the howitzer, or mortar, of its day and could throw a hundred-pound stone 600 yards in a high arc to strike the enemy behind his wall or batter down his defenses. "In the middle of the ropes a wooden arm rises like a chariot pole," wrote the historian Marcellinus. "At the top of the arm hangs a sling. When battle is commenced, a round stone is set in the sling. Four soldiers on each side of the engine wind the arm down until it is almost level with the ground. When the arm is set free, it springs up and hurls the stone forth from its sling." In early times the weapon was called a "scorpion," for like this dreaded insect it bore its "sting" erect.

FIGURE 2—CATAPULT.

The trebuchet was another war machine used extensively during the Middle Ages. Essentially, it was a seesaw. Weights on the short arm swung the long throwing arm.

FIGURE 3—TREBUCHET. A heavy trebuchet could throw a 300-pound stone 300 yards.

These weapons could be used with telling effect, as the Romans learned from Archimedes in the siege of Syracuse (214-212 B.C.). As Plutarch relates, "Archimedes soon began to play his engines upon the Romans and their ships, and shot stones of such an enormous size and with so incredible a noise and velocity that nothing could stand before them. At length the Romans were so terrified that, if they saw but a rope or a beam projecting over the walls of Syracuse, they cried out that Archimedes was leveling some machine at them, and turned their backs and fled."

Long after the introduction of gunpowder, the old engines of war continued in use. Often they were side by side with cannon.