The Muro Torto (literally, the “misshapen” or “twisted” wall) runs along Rome’s Villa Borghese and is part of the well-preserved Aurelian walls, which date to the late 3rd century CE (Dey 225). Its irregular shape accommodates the Pincian Hill. Measuring and documenting the Muro Torto as an architect, Piranesi crowds this print with three conventions of architectural representation, which the caption scrupulously identifies: “pianta” (plan), “spaccato” (section), and “elevazione” (elevation). The page is divided vertically in two halves, depicting different parts of the wall: single-story on the left and two-story on the right. At the bottom of the page there are two plans (A) for these different parts. Here, Piranesi uses light stippling as poche (the black portion of an architectural plan representing solid, as walls and columns), and blank space for the niches. The left wall plan is composed of rounded niches, while the right has trapezoidal niches. The right wall is articulated by a series of rectangular cavities (B). Both walls have a series of canals (C) for draining water at the back of their niches. Between the two plans is a close-up of a terracotta water channel (H). In antiquity, terracotta served as a common material for water pipes, as it was less expensive and, as the ancient Romans knew, safer than lead. In fact, the Roman military engineer and architect Vitruvius (c. 80–70 BCE-after c. 15 BCE) recommends terracotta over lead for water pipes (Vitruvius 105).  

The elevations (D) are projected from the plans below, as if on an architect’s drafting board, and can be read in sequence. Both elevations are rendered with vegetation growing on top of the wall and within crevices, reminding viewers that despite the wall’s good condition, they are still looking at a ruin; the plans alone do not suggest the wall’s true age. The niches are punctured by numerous holes (G) for water drainage in the wall, which is a single instance in the plan (C) but are multiple in the elevation. There is a section (E) of the two-story wall at the center of the page, positioned between the two elevations. Like the plans below, the wall is stippled.  

A scale is prominent across the bottom of the print, with increments of five Roman feet. Curiously, this is the only non-map print in the volume that contains a scale. In this case, the scale also indicates the vast size of the wall: the height measures approximately eighty Roman feet. While other prints in the volume rely on human figures to convey size, here Piranesi relies strictly on the architect’s scale. Barbara Maria Stafford has described Piranesi’s “surgical” method of exposing building materials (1991, 56-66). This print, methodical and measured, itself resembles an autopsy of the wall, in which Piranesi approaches it through different angles and conventions to peel back its various layers. (SAH)