7.23.1Mūrī autem omnēs Gallicī hāc ferē fōrmā sunt.All Gallic walls are built roughly in this way.Note. Chapter 23 describes the murus Gallicus, a wall of timber, earth and stone. Archaeologists have found walls built in just this way at many Gallic sites. 7.23.1Trabēs dērēctae perpetuae in longitūdinem paribus intervallīs, distantēs inter sē bīnōs pedēs, in solō collocantur.Straight beams, unbroken along their length, are laid on the ground at equal intervals, two feet apart from one another. 7.23.2Hae revinciuntur intrōrsus et multō aggere vestiuntur: ea autem, quae dīximus, intervalla grandibus in fronte saxīs effarciuntur.These are tied together on the inner side and covered with a great deal of earth; but the intervals we have mentioned are packed at the front with large stones. 7.23.3Hīs collocātīs et coagmentātīs alius īnsuper ōrdō additur, ut idem illud intervallum servētur neque inter sē contingant trabēs, sed paribus intermissae spatiīs singulae singulīs saxīs interiectīs arte contineantur.When these have been laid and fitted together, another row is added on top, in such a way that the same interval is kept and the beams do not touch one another, but, separated by equal spaces, each one is held tight by a single stone set between it and the next.Note. singulae singulīs saxīs interiectīs … contineantur: 'each beam is held firm by a single stone set between'. The distributive singulī means 'one each'.
7.23.4Sīc deinceps omne opus contexitur, dum iūsta mūrī altitūdō expleātur.In this way the whole work is woven together course by course, until the wall reaches its proper height. 7.23.5Hoc cum in speciem varietātemque opus dēfōrme nōn est alternīs trabibus ac saxīs, quae rēctīs līneīs suōs ōrdinēs servant, tum ad ūtilitātem et dēfēnsiōnem urbium summam habet opportūnitātem, quod et ab incendiō lapis et ab ariete māteria dēfendit, quae perpetuīs trabibus pedēs quadrāgēnōs plērumque intrōrsus revīncta neque perrumpī neque distrahī potest.This work is not unsightly to look at and in its variety, with alternating beams and stones that keep their rows in straight lines, and it also has the greatest advantages for the usefulness and defence of towns, because the stone protects it from fire and the timber from the battering-ram, since the timber, tied together on the inner side with continuous beams generally forty feet long, can neither be broken through nor pulled apart.Note. Hoc cum … nōn est dēfōrme …, tum … habet: 'not only is this work not unsightly …, but it also has …'. A cum … tum pair often means 'both … and' or 'not only … but also'.