MOLOCH The Barbarians had no need of a circumvallation on the side of Africa, for it was theirs.

But to facilitate the approach to the walls, the entrenchments bordering the ditch were thrown down.

Matho next divided the army into great semicircles so as to encompass Carthage the better.
The hoplites of the Mercenaries were placed in the first rank, and behind them the slingers and horsemen; quite at the back were the baggage, chariots, and horses; and the engines bristled in front of this throng at a distance of three hundred paces from the towers.
Amid the infinite variety of their nomenclature (which changed several times in the course of the centuries) these machines might be reduced to two systems: some acted like slings, and the rest like bows.
The first, which were the catapults, was composed of a square frame with two vertical uprights and a horizontal bar.

In its anterior portion was a cylinder, furnished with cables, which held back a great beam bearing a spoon for the reception of projectiles; its base was caught in a skein of twisted thread, and when the ropes were let go it sprang up and struck against the bar, which, checking it with a shock, multiplied its power.
The second presented a more complicated mechanism.

A cross-bar had its centre fixed on a little pillar, and from this point of junction there branched off at right angles a short of channel; two caps containing twists of horse-hair stood at the extremities of the cross-bar; two small beams were fastened to them to hold the extremities of a rope which was brought to the bottom of the channel upon a tablet of bronze.
This metal plate was released by a spring, and sliding in grooves impelled the arrows.
The catapults were likewise called onagers, after the wild asses which fling up stones with their feet, and the ballistas scorpions, on account of a hook which stood upon the tablet, and being lowered by a blow of the fist, released the spring.
Their construction required learned calculations; the wood selected had to be of the hardest substance, and their gearing all of brass; they were stretched with levers, tackle-blocks, capstans or tympanums; the direction of the shooting was changed by means of strong pivots; they were moved forward on cylinders, and the most considerable of them, which were brought piece by piece, were set up in front of the enemy.
Spendius arranged three great catapults opposite the three principle angles; he placed a ram before every gate, a ballista before every tower, while carroballistas were to move about in the rear.