“Sometimes the shields were disposed in such a way as to make the Testudo slope. The soldiers in the first line stood upright, those in the centre stooped a little, and each line successively was a little lower than the preceding, down to the last, where the soldiers rested on one knee. Such a disposition of the shields was called _Fastigata Testudo_, on account of their sloping like the roof of a building. “The advantages of this plan were obvious. The stones and missiles thrown upon the shields rolled off them like water from a roof; besides which, other soldiers frequently advanced upon them to attack the enemy upon the walls. The Romans were accustomed to form this kind of Testudo as an exercise in the games of the Circus.” On the right hand of the illustration is shown a portion of a Testudo of three ranks, taken from the Antonine column. On the left is an ordinary Tortoise. Sometimes the Testudo was a covered machine on wheels, and guarded above with a supplementary roof of wet hides arranged in scale fashion, so as to prevent it from being set on fire by the besieged, and to throw off the heavy missiles which were dropped upon it. Under cover of this Testudo, the soldiers could either undermine the walls, or bring a battering-ram to bear upon them, while the men who worked it were safely under cover. As to the battering-ram itself, we shall presently treat of it. THE FORT. As we have treated of one of the modes by which Forts were assaulted, we will now come to the Fort itself. The transitions in Fort-making are too curious to be omitted from the present book. As soon as war became organized, a Fort of some kind was necessary. The simplest mode of making a Fort was evidently to dig a deep trench, and throw up the earth on the inside, so as to form a wall. Let such a trench be square or circular, and there is a simple but powerful Fort, by means of which a comparatively small garrison could defend themselves against a superior force. The Romans were great masters of this art, fighting as much with the spade as the sword. So strong and thorough was the old Roman work that many of their camps still remain, and will remain for centuries if man does not deface them. Such, for example, are Cæsar’s camp, near Aldershot, and the fine camp at Lyddington, in Wiltshire, almost every detail of which is preserved. Roman camps are all constructed on the same model, the general’s place, or Prætorium, being in the centre, whence he issued his orders, and the commanders under him occupying the corners. Thus, no matter how he might be shifted from one corps to another, every Roman soldier knew his way about the camp without needing to see it, and could tell at any moment where to find any officer. [Illustration: ELK FORT.] [Illustration: MOUND FORT.]