Figura 7. Restituzione fotorealistica del locale visto dalla zona absidale. A sinistra, mappa luminanze
(cd/m 2 ); a destra, mappa illuminamento (lx) in falsi colori / Rendering of the room seen from the apse
area. On the left, the luminance (cd/m 2 ) map; on the right, the illuminance (lx) map in false colours
philological and historical-cultural aspects.
The complex, where in the past the Seminary
of the Florentine Archdiocese was established
and which today is the seat of the School
of Engineering of the University of Florence, was
owned by the Dell’Accetta family until the 14th
century. It then became the object of various
buying and selling, which saw, over the years,
the succession of many different owners: the
Del Cittadino, Ridolfi, Montjoi, Arrighi, Asturillo,
Baglioni, Gerini, and Landini families, until
the purchase, in 1880, by the Sicilian Prince
of Pandolfina e San Giuseppe, Ferdinando
Monroy Barlotta, Senator of the Kingdom, whose
wife, Laura Temple-Bowdoin, was responsible
for the attribution of the name “Villa Cristina”
to the complex. Subsequently, it was owned
by Mrs Woronzoff, by Mr Labouchère, and by
the Englishman Mr Rennih. The latter initially
rented the villa as a hotel and then sold it to
the Mensa vescovile – the ecclesial assets that
supported the Bishop –, who enlarged the
building and established there the Seminary
of the Florentine Archdiocese (inaugurated
in 1938 by Cardinal Elia Dalla Costa), and where
the seminarians of the Collegio Eugeniano
and those of the Convento della Calza also
settled down. The seminar activity remained
in this building only for a few decades, as the
gradual reduction of the number of students
in the post-war period made the large building
practically unused. Therefore, in 1980, the
Cardinal Archbishop Giovanni Benelli sold the
Seminary of Montughi to the University of
Florence, which made it the seat of the School
of Engineering 6 . Figure 2 shows the historical
maps, and Figures 3, 4, and 5 some photographs
of Villa Cristina, from the Alinari Archives
and the Brogi Archives of Florence.
Study of the luminous climate
Through a critical-comparative analysis
of the experimental results it was possible
Figura 8
28
LUCE 328 / RICERCA E INNOVAZIONE
to study the luminous climate existing in the
environment, characterized by a combination
of natural light (although in a small amount
and all coming from above) and artificial light.
It is well known that the lighting and the natural
light existing in a cultural heritage building and/
or environment can contribute to the protection,
enhancement, and conservation of historical
and architectural significance 7 , but if we read
this by means of the Information Theory 8 ,
then the lighting and the natural light become
channels for the transmission of information
content, signals, and information. A large
number of measurement points on the
horizontal floor of the reading room, on the
tables, and on the floor of the apsidal area,
was joined to a set of particularly important
points identified on the floor of the two side
galleries, on the horizontal surfaces of the
worktops, and on the vertical portions of the
shelves, at a height of 1.60 m (approximately
the height of the eyes of a normotype).
Figure 6 shows a map with the main
measurement points. Starting from the results
of the measurement campaign conducted
on different days, in order to take into account
the different sky and sun conditions during
the times of use of the library, it was possible
to obtain the variation and distribution of the
illuminance values as a function of the sky
conditions and of the “path of the Sun”, from
a radiometric and a photometric point of view.
In particular, what you could observe from the
study was that the natural light in the
environment was obviously designed for
a church building, and was therefore
predominantly diffused and with an downward
distribution. The incoming natural light brought
information within itself: it was clearly derived
from a design-thinking that wanted to
contribute to the architectural space with
relevant aesthetic, emotional, and perceptive
effects, and with the appropriate levels
Figura 9
of functional, celebrative, and liturgical lighting,
both for the assembly and for the presbytery and
the adjacent spaces. In effect, its colour is due
to its own emission spectrum, not to the result
of the combination of transmission, reflection,
and specular and diffuse refraction coming from
the presence of stained coloured glass or other
particular surfaces, being these predominantly
monochrome. It was in fact connected to the
position of the sun and, therefore, to the value
of the angle of incidence, with respect to which
the transparency coefficient (solar and luminous)
of the existing simple clear glasses changed
throughout the day. Using the Information
Theory 8 it was possible to interpret and analyse
the signal carried by the luminous fluxes due to
the natural light, which not only told us about
the finiteness of the usable negentropy flow
(the quality of light) deriving from the sun
and the sky, or the conditions of its control and
use, but allowed us, thanks to the information
contents detectable from the distribution and
variation fields of illuminance and luminance,
to philologically rebuild the space in its original
areas and functions. The artificial light, on the
other hand, flattened the information content
of the natural light, if it did not even conceal it.
Through the study of the natural light trend,
we were able to identify, re-read, and recover
the historical and philological information and
thus give a rhythm to the areas and volumes
that belonged to the history of the church:
the narthex, or the short atrium as wide as the
church; the very evident central nave, running
up to the choir; the side aisles, that is the long
corridors that flank it; the choir, the high altar
area, barely identifiable due to architectural
transformations; the apse, that is the semi-
circular portion placed behind the choir and
the final part of the whole environment, clearly
visible because marked by the luminous path
of the sun,. These areas changed their intended
use: reading and study tables are now
everywhere. The analysis of the experimental
data showed an average measurement error
of about 25%, calculated with the standard
deviation and the Chi-Squared test: this was
due to the extreme variability of the typical sky
for medium-low latitudes, such as that of
Florence. In particular, it was noted that the
illuminance values in the reading room area
were less than 300 lx, even in the evening hours
with the only artificial lighting; in the “apse
area”, they were less than 150 lx; the central
nave showed illuminance values between 150 lx
and 200 lx, with a blend of natural and artificial
lighting. None of these values complied with
the standard requirements for environments
intended for visual tasks, such as reading/writing
in a library (Table1): as a matter of fact, average
illuminance values of 500 lx were required.