‹‹‹ Vitr. 10.12.1 | Table of Contents | Vitr. 10.13.1 ›››
2The ends of the ropes pass through the holes of the capitals, and brought through on the other side, they are then passed round the axle of the windlass, which is turned by the aid of levers, till the ropes, both drawn tight, give the same tone when struck by the hand. Then they are confined at the holes with wedges, to prevent their slipping. Being passed through to the other side, they are in a similar way tightened by the levers and axles till the tones are similar. Thus by the use of the wedges, catapultæ are adjusted, according to the effect of musical tones on the ear.
2Next, the loops of the strings are put through the holes in the capitals, and passed through to the other side; next, they are put upon the windlasses, and wound round them in order that the strings, stretched out taut on them by means of the handspikes, on being struck by the hand, may respond with the same sound on both sides. Then they are wedged tightly into the holes so that they cannot slacken. So, in the same manner, they are passed through to the other side, and stretched taut on the windlasses by means of the handspikes until they give the same sound. Thus with tight wedging, catapults are tuned to the proper pitch by musical sense of hearing.
On these things I have said what I could. There is left for me, in the matter of sieges, to explain how generals can win victories and cities be defended, by means of machinery.