1. Now in rubble structures we must first inquire about the sand, that it be suitable formixing material into mortar, and without the admixture of earth. Now the kinds of quarried sand are these: black, white, red, and from lignite. Of these, that which makes a noise when rubbed in the hand will be best; but that which is earthy will not have a like roughness. Also, if it is covered up in a white cloth, and shaken up or beaten, and does not foul it, and the earth does not settle therein, it will be suitable.
2. Sin autem non erunt harenaria unde fodiatur, tum de fluminibus aut e glarea erit excernenda, non minus etiam de litore marino. sed ea in structuris haec habet vitia, difficulter siccescit, neque onerari se continenter paries paritur nisi intermissionibus requiescat, neque concamarationes recipit. marina autem hoc amplius quod etiam parietes, cum in is tectoria facta fuerint, remittentes salsuginem corium dissolvunt.
2. But if there are no sand-pits whence it may be dug, then it must be sifted out from the river bed or from gravel, not less also from the sea-shore. But such sand has these faults in buildings: it dries with difficulty, nor does the wall allow itself to be loaded continuously without interruptions for rest, nor does it allow of vaulting. But in the case of sea sand, when plastered surfaces are laid upon walls, the walls discharge the salt of the sand and are broken up.
3. Fossiciae vero celeriter in structuris siccescunt, et tectoria permanent, et concamarationes patiuntur, sed eae quae sunt de harenariis recentes. si enim exemptae diutius iacent, ab sole et luna et pruina concoctae resolvuntur et fiunt terrosae. ita cum in structuram coiciuntur, non possunt continere caementa, sed ea ruunt et labuntur onera quae parietes non possunt sustinere. recentes autem fossiciae cum in structuris tantas habeant virtutes, eae in tectorio ideo non sunt utiles quod pinguitudine eius calx palea commixta propter vehementiam non potest sine rimis inarescere. fluviatica vero, propter macritatem inutilis signino, liaculorum subactionibus in tectorio recipit soliditatem.Translation
3. But quarry sand quickly dries in buildings, and the surface lasts; and it admits of vaulting, but only that which is fresh from the pit. For if after being taken out it lies too long, it is weathered by the sun and the moon and the hoar frost, and it is dossolved and becomes earthy. Thus when it is thrown into the rubble, it cannot bind together the rough stones, but these collapse and the loads give way which the walls cannot maintain. But while fresh pit sand has such virtues in buildings, it is not useful in plaster work; because owing to its richness, the lime when mingled with straw cannot, because of its strength, dry without cracks. But river sand because of its fineness (like opus signinum), when it is worked over with polishing tools, acquires solidity in the plaster.
Chapter 3 of this book was all about adbobe. With chapter 4 Vitruvius starts the description of stone masoned walls. The Romans used lime mortar. Lime mortar is a mixture of lime with sand. It was thus of the utmost importance to find and use the appropriate kind of sand to get a firm mortar. That's probably why Vitruvius starts with his account on sand. Again he is clearly talking from his own experience, not depending from external sources.
Les dix livres d'architecture de Vitruve, Corrigés et traduits en 1684 par C. Perrault, Paris, 1684.
Vitruvius, De Architectura libri X, ed. F. Granger, London, 1962.
Ton Peters, Vitruvius, Handboek bouwkunde, Amsterdam, 1999.
A.Boëthius-J.B.Ward-Perkins, Etruscan and Roman Architecture, Harmondsworth, 1970
A.McKay, Vitruvius, Architect and Engineer, London, 1978
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