San Lorenzo was the church of the Medicis. It is refered
to as the "Old Sacristy" to distinquish it from the
"New Sacristy" created by Michelangelo about 100 years
later. Brunelleschi was commisioned to transform the Early Christian
Basilica which he did in terms of making it a purely Renaissance
space.
Circles, half circles, rectangles, and squares
are kept as at the Innocenti within a clear-cut, all embracing
system of modules of surface and space, diminishing systematically
as one looks down the nave. The entire interior is marked by clarity,
harmony, measure and reason. Everything is connected by simple
mathematical relationships. It is like a graph that measures
not only the perspective recession but also the proportions between
the width of the bays, the height of the columns, and that of
the arches. The columns diminish in size at a rate equal to the
regular intervals at which they are placed. The vanishing point
is somewhere beneath the choir.
The nave arcades, suported by unfluted Corinthian columns, sustain
a flat wall without triforium, pierced by a clerestory of arched
windows. Flanked by Corinthian pilasters, the side aisles are
covered by pendentive vaults supported on tranverse arches; the
nave is roofed by a flat, coffered ceiling, whose squares provide
a convenient graph with which to measure the inward spatial recession.
All is measure, reason, proportion, harmony accentuated by Brunelleschi's
use of pietra serena, the gray stone which is like slate.