Regulae ferreae aut arcus fiant, eaeque uncinis ferreis ad contignationem suspendantur quam creberrimis; eaeque regulae sive arcus ita disponantur, uti tegulae sine marginibus sedere in duabus invehique possint, et ita totae concamarationes in ferro nitentes sint perfectae.
Iron bars or arches are to be made and hung on the timber close together with iron hooks. And these rods or arches are to be placed so far apart that the tiles without raised edges may rest upon, and be carried by them; thus the whole vaulting is finished resting upon iron.
final_alignments\Vitruvius_Architecture_Book_5.json