I.12.4
DIFFERENTIATION OF LEVELS IN
DOUBLE-STORIED STRUCTURES
Whether a building on the Plan is a single- or a double-storied
structure cannot be inferred from its linear layout.
Structures of several stories are designated as such by their
explanatory titles. One must infer from this that other
buildings, which are without such explanations, are one-storied.
The multi-level buildings are: the Dormitory (fig.
208), the Refectory (fig. 211), and the Cellar (fig. 225), the
Abbot's House (fig. 251), the choir and crypt of the Church,
the Sacristy and the Vestry, the Scriptorium and the
Library (fig. 99). In projecting the design of these buildings
onto his parchment, the draftsman is not consistent, but
switches from the rendering of the ground floor to that of
the second story, whichever is of greater interest to him.
Thus, he depicts the layout of the Refectory with its tables
and benches in full detail and merely indicates with the
inscription supra uestiarium that the Refectory is surmounted
by an upper level serving as storage for the
monks' clothing (fig. 211). In the case of the Dormitory
(fig. 208) he follows the opposite procedure. He depicts the
layout of the upper story with the beds of the monks and
explains with the inscription subtus calefactoria dom' that the
building has a lower level, which is occupied by the warming
room of the monks. Conversely, in the case of the Cellar
(fig. 225), he dwells with loving care on the two impressive
rows of wine and beer barrels set up on the ground floor,
and suggests by the legend supra lardariū. &' necessariorū
repositio that the Cellar is surmounted by the Larder. In
only one case, namely that of the choir and the crypt, are
elements of two levels combined on the same surface. The
area is of crucial importance from a liturgical point of view,
and the draftsman uses this device to make absolutely sure
that it is clearly understood in what manner the pilgrims
are given access to the tomb of St. Gall.
The designers of the Forma urbis Romae also seem to
have felt free to switch from the predominantly ground-floor
layout method to an ideographic rendering of the
superstructure, when this was a more interesting and
significant aspect. Buildings such as the Colosseum (fig.
50.A) or the Theater of Marcellus (fig. 51.A) are rendered in
bird's-eye view, or in a combination of bird's-eye view and
planimetrical projection. Thus in the Colosseum a sequence
of elliptical lines defines the four major sections of the
theater, corresponding to the podium and the three maenia
for the spectators, suggesting rows, yet not specifically
representing them in their actual number.[257]
In the representation
of the Theater of Marcellus (fig. 51), in addition
to the semicircular tiers of seats and the passage ways
(praecinctiones) by which these are separated, there is a
complex system of fan-shaped passages that intersect the
seats radially. Some of these represent the ascending stairs
in the superstructure that connect the three tiers (cavea) of
seats (and would have been visible to anyone seated in the
theater); others show the hidden ramps (cryptae) in the substructure
(not visible from above) that give access to the
upper deck through openings (called vomitoria, because
they "spit out" the masses of spectators into the galleries).
This is an ideogrammatic contraction on one and the same
plane of elements belonging to different levels and not
visible simultaneously from the same point of inspection.
A comparison of the portrayal of these two buildings on the
Forma urbis with modern architectural drawings of the same
subjects (figs. 50.B and 51.B) shows in the rendering of these
details how little they conform to a consistent scale or to
dimensional accuracy—and how difficult it is (especially
in the case of the Marcellus Theater) to determine what
belongs to the upper deck and what to the supporting
structure. To render the relationship of all these elements
in accurate planimetrical projection would have necessitated
making as many separate plans as there are different stories
in each building (or a combination thereof as is done in
figs. 50.B and 51.B), which was clearly beyond the scope and
function of the
Forma urbis. In his rendering of the Colosseum
the designing architect confined himself to portraying
in a crudely abbreviated form what a spectator
would have seen of the elliptical seating arrangement of this
amphitheater, had he hovered vertically above it. In his
portrayal of the Theater of Marcellus, by contrast, he made
an attempt to combine distinctive features of the substructure
(not visible from above) with distinctive features
of the upper deck (visible from above) without making it
clear what belongs to one, what to the other.
The conception of the Plan of St. Gall is highly superior
in this respect. In his layout of the transept and the presbytery
of the Church (fig. 99), where the component parts of
several levels are shown in simultaneous projection, the
author defines the interrelationships so clearly that the eye
finds no trouble in establishing that the presbytery is
raised above the level of the transept by seven steps and
that the vaulted arms of the ambulatory corridor crypt lie
beneath that level. He makes it unequivocally clear that the
longitudinal arms of that crypt run along the outer surface
of the choir walls and terminate in a transverse arm that
gives access to the tomb of St. Gall. He leaves no doubt
about the length and width of these arms.
With all of this I do not mean to imply that a Roman
architect might not have been equally proficient. To place
this entire problem into proper historical perspective the
reader must here be reminded of the fact that the Forma
urbis was not only drawn at a considerably smaller scale
(1:240) than the Plan of St. Gall (1:192), but also that it
included buildings of exasperating constructional complexity
and most important of all, that it was never meant
to serve as a building plan to be used in construction; it
was more in the nature of a real estate record. Considering
its scale and its purpose, it renders with admirable conceptual
simplicity the layout of such complex structures as
the Colosseum and the Theater of Marcellus.[258]
