‹‹‹ Vitr. 10.13.6 | Table of Contents | Vitr. 10.13.8 ›››
7He describes the auger (terebra) thus: the machine is made like a tortoise, as in those for the reception of the catapultæ and balistæ, and in the middle thereof is a channel on the pilasters fifty cubits long, one high, and across it an axle. In front, on the right and left, are two pulleys, by means of which is moved a beam with an iron point at its end, which works in the channel. Under the channel are rollers, which give it an easier and stronger motion. Above the beam an arch is turned to cover the channel, and receive the raw hides with which the machine is covered.
7He explained the principles of the borer as follows: that the machine itself resembled the tortoise, but that in the middle it had a pipe lying between upright walls, like the pipe usually found in catapults and ballistae, fifty cubits in length and one cubit in height, in which a windlass was set transversely. On the right and left, at the end of the pipe, were two blocks, by means of which the iron-pointed beam, which lay in the pipe, was moved. There were numerous rollers enclosed in the pipe itself under the beam, which made its movements quicker and stronger. Numerous arches were erected along the pipe above the beam which was in it, to hold up the rawhide in which this machine was enveloped.