‹‹‹ Vitr. 1.5.7 | Table of Contents | Vitr. 1.6.1 ›››
8I do not think it requisite to dilate on the materials whereof the wall should be composed; because those which are most desirable, cannot, from the situation of a place, be always procured. We must, therefore, use what are found on the spot; such as square stones, flint, rubble stones, burnt or unburnt bricks; for every place is not provided, as is Babylon, with such a substitute for lime and sand as burnt bricks and liquid bitumen; yet there is scarcely any spot which does not furnish materials whereof a durable wall may not be built.
8With regard to the material of which the actual wall should be constructed or finished, there can be no definite prescription, because we cannot obtain in all places the supplies that we desire. Dimension stone, flint, rubble, burnt or unburnt brick,—use them as you find them. For it is not every neighbourhood or particular locality that can have a wall built of burnt brick like that at Babylon, where there was plenty of asphalt to take the place of lime and sand, and yet possibly each may be provided with materials of equal usefulness so that out of them a faultless wall may be built to last forever.