University of Virginia Library

I.12.7

THE PLAN IN HISTORICAL
PERSPECTIVE

The method of rendering used in the Plan of St. Gall is
closely related to that displayed in the great marble plan
of the city of Rome made under Emperor Septimius
Severus, and belongs to the same historical tradition of
rendering. Functionally, these two plans have little in
common. The Forma urbis delineates an existing condition,
the layout of a grown city. The Plan of St. Gall does not
define how it is, but how it should be. These differences,
however, had little, if any, effect on the manner in which
the two plans were rendered.

Like the architects who designed the Forma urbis, where
wall thicknesses are indicated in a few judiciously selected
categories of building, the author of the Plan of St. Gall
would have been fully capable of rendering the walls of his
buildings in full thickness. Like the former, he chose not
to employ this method for the same reason an architect
today would use single line projection instead of double line
projection for the rendering of walls, namely, the complexity
of his subject and the smallness of the scale in which
it was drawn. There is good evidence that the Forma urbis
was still in place on the walls of SS. Cosmas and Damian
in the Carolingian period,[260] and thus could have been seen
by the Frankish emperors who visited Rome and the
architects who traveled in their following. Moreover, there
are more substantive reasons for thinking that the designer
of the Plan of St. Gall was familiar with the layout of the
city of Rome.[261]

If it was the purpose of the Plan of St. Gall to depict on
a single spread of parchment the layout of the buildings and
furnishings of a paradigmatic medieval monastery, it would
be hard to improve upon the method of rendering that the
designer chose in order to accomplish this task. One of the
most successful features is the freeness and flexibility of
mind with which the designer switches from the rendering
of the ground floor to the rendering of an upper level—

wherever the complexity of the layout of the upper floor
suggested such action—and chooses to explain the nature
and function of the repressed story with the aid of an
explanatory title. To do it differently would have required
supplementary drawings. Even from a purely technical
point of view the Plan of St. Gall is a highly sophisticated
document. It tells the story of a very complex architectural
situation with ingenious simplicity. One of the designer's
overriding preoccupations was the retention of clarity in
the over-all appearance of the settlement. He was detailed
where attention to detail was imperative in the light of
function; but he did not hesitate to omit almost entirely
such features as stairs where their delineation would have
impaired the clarity and easy readability of the primary
elements of his drawing.

With all its medieval idiosyncraises, the Plan of St. Gall
has a surprisingly modern flavor. Its analytical precision
and clarity compare favorably with any modern site plan
drawn at a comparable scale. The designer did not hesitate
to enliven his plan with elevations in a few places, where
this method promised to convey his thoughts more fully;
but in departing in this manner from his general mode of
rendering he proceeded with a deep sense of discrimination
and with conspicuous self-restraint. Above all he carefully
resisted any temptation to indulge in architectural pictorialism.
This quality is strikingly revealed if one compares
the Plan of St. Gall with the twelfth-century plan of the
Waterworks of Christchurch Monastery at Canterbury
(fig. 52) where everything is shown in elevation as in a
child's drawing.

[ILLUSTRATION]

50.B FLAVIAN AMPHITHEATRE (COLOSSEUM)
PLAN

ROME, ANTIQUARIUM COMMUNALE DEL CELIO

[after Durm, 1885, 344, fig. 310]

This composite plan of the Colosseum shows four different levels.

[ILLUSTRATION]

50.A FORMA URBIS ROMAE

ROME, ANTIQUARIUM COMMUNALE DEL CELIO

[after Carretoni, 1960, vol. II, pl. XXIX]

These fragments show the seating arrangement of the Colosseum as if
seen from above.

COMMENT:

for figure 50.A and FORMA URBIS ROMAE, generally

The illustration, using the lower portion of the graphic scale graduated 0-100
metres, scales 186 metres on its major axis. This compares with 187.5 metres
(615 feet) commonly given for the length of the Colosseum, a variance of less
than 1 percent between present day measurements and the sculptured mural
version that records the measurements of engineers at a time when the plan
was cut in place in stone.

FORMA URBIS ROMAE stands as a remarkable demonstration of the state of
the art of drawing, with knowledge not only of measure, but the skill of taking
measurements and translating these measurements precisely into a graphic
configuration of great accuracy. Far exceeding any practical function, such as
a cadastral plan for administrative purposes, must have been its effect on the
mind of the beholder. The impact on a viewer of the plan of Rome, incised in
stone for all time, spread across a wall 59 feet wide and rising, on its base,
to 56 feet, could not but impress even the most sophisticated Roman. For the
visitor from beyond the hills of Rome and from lands afar, the effect could
not have been less than overwhelming.

The conjecture is tempting, that the sculptural mural map may have been
seen, if not by the great Carolus himself, by learned men of his court and
soldiers of his entourage in the course of their duties in Rome.

A record of achievement, symbol of law and order and authority, invincible
and eternal, it seemed without doubt, and a fitting inspiration as well, for an
emperor and his sometimes loyal and always ambitious followers.

The comparative scale, included with the illustration, compares the scale of the
sculptured plan above, the line (40 cm), with the actual "on the ground"
measure (100 m), below. The ratio, 41.7 cm. to 100 m, is almost 1:240.
The ratio between the scale of illustration 50.A and the Colosseum computes
at about 1:951.7 (derived from the relation between 19.7 cm = 187.5 m).
Thus the illustration is about ¼ the size of the rendering of the plan on the
sculptured wall.

1/952/1/240 = 240/952 = 1/3.98 [or ¼]