ENGINES OF WAR were certainly known much earlier than the Greek writers appear to admit, since figures of them occur in Egyptian monuments, where two kinds of the testudo, or pent-house, used as shelters for the besiegers, are represented, and a colossal lance, worked by men who, under the cover of a testudo, drive the point between the stones of a city wall. The chief pro jectiles were the catapulta for throwing darts, and the balista for throwing stones. Both these kinds of instruments were prepared by Uzziah for the defence of Jerusalem (2 Chron. xxvi. 15), and bat tering the wall is mentioned in the reign of King David (2 Sam. xx. 15) ; but the instruntent itself for throwing it down may have been that above noticed, and not the battering-ram. The ram was, however, a simple machine, and capable of de molishing the strongest walls, provided access to the foot was practicable ; for the mass of cast metal which formed the head could be fixed to a beam lengthened sufficiently to require between one and two hundred men to lift and impel it ;+ and when it was still heavier, and hung in the lower floor of a movable tower, or helipolis, it became a most formidable engine of war—one used in all great sieges from the time of Demetrius, about B. C. 306,
till long after the invention of gunpowder. Towers of this kind were largely used at the destruction of Jerusalem by the Romans. Of the balistm and catapultre it may be proper to add that they were of various powers. For battering walls there were some that threw stones of fifty, others of one hundred, and some of three hundred weight ; in the field of battle they were of much inferior strength. Darts varied similarly from small beams to large arrows, and the range they had exceeded a quarter of a mile, or about 45o yards. All these engines were constructed upon the principle of the sling, the bow, or the spring, the last being an elastic bar, bent back by a screw or a cable of sinews, with a trigger to set it free, and contrived either to impel darts by its stroke, or to throw stones from a kind of spoon formed towards the summit of the spring.—C. H. S.