Stereotomy
In the first sense of the term, stereotomy is the art of cutting in different volumes for assembly; in architecture, it refers more specifically to the art of cutting stones for the construction of arches, tubes, domes or flights of stairs ... If we still speak of "stereotomy wood" about assembling the timber, it is found that this effect disappears in different architectural dictionaries, be it that of D'Aviler, authoritative in the eighteenth century or the architectural vocabulary published by the Department for Business Culture in 1972. This shift in meaning is not accidental. Unlike carpenter who makes the skeleton of a volume, which determines boilermaker skin, stonemason works directly the mass of material to which any shape can be given. Through the judicious assembly of small stones cut in a wedge shape, the quoins or segments, which do not take them as the pressure exerted on each of its neighbors, the tailor sends architectural elements reaching. But unlike the apparatus walls, stereotomy implies the realization of non-planar surfaces (or horizontal flat surfaces) and frequent interpenetration such surfaces, which poses difficult problems in the fitter to determine each voussoir . In ancient stereotomy also systematically avoids this type of penetration and knows only the arches and barrel vaults. The first examples of stereotomy "learned" are probably in the fourth century Christian Syria where there are paired tubes or domes on pendants. The Romanesque stereotomy offer outstanding examples of architecture clavée, the most famous of which is the spiral staircase of the abbey of Saint-Gilles du Gard.
