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0521551331 c 01 -p 3 a CUNY 160 /Joannides 052155 133 1 January 11 , 2007 10 : 18
CATALOGUE 54 WHOLLY OR PARTIALLY AUTOGRAPH SHEETS 257principally architectural, St. Peter’s, which he envisaged
as a domed, centrally planned church, overlapped in his
thinking with three other ecclesiastical buildings: San
Giovanni dei Fiorentini, also planned as a centralised
domed building; the Sforza Chapel in the church of Santa
Maria Maggiore, also, in effect, centrally planned; as well
as the conversion of the huge central hall of the Baths of
Diocletian into the church of Santa Maria degli Angeli.
Michelangelo often made drawings for different
projects on the same side of the same sheet but in the
present case recto and verso seem to have been reserved
for different projects and the verso may have been drawn
a little later than the recto. The recto, which shows the
upper part of the dome and the lantern in section, like
the Haarlem drawing (AZ 9 recto/VT 67 /Corpus 596 ;
black chalk over ruled stylus lines with compass work,
397 × 232 mm), was clearly left as a sketch and was not
developed. It, like the broken-off beginning of a letter that
accompanies it, refers to the outstanding problem faced by
Michelangelo in the last years of the155 0s: the shape of the
dome of St. Peter’s. This issue is extremely complicated
and can only be outlined here. Nevertheless, it seems clear
that, by155 7,much of the structure of the drum of St.
Peter’s had been determined, although not constructed,
and even though Michelangelo still had considerable
room for manoeuvre, it was now time to think about
the dome that was to surmount it. According to Vasari,
Michelangelo prevaricated for some months and then
made a small-scale model in clay, a medium that looks
back to his earliest years in the Medici garden and that he
also employed early in his preparation of the fac ̧ade of San
Lorenzo, but that is not known to have been employed by
him for architectural projects in the intervening period.
No doubt Michelangelo chose clay because it permitted
him to mould and re-mould as he wanted. It is unlikely
that he made only one model of this type, and he may
also have employed wax. To employ clay was inevitably
to accept imprecision and Michelangelo’s concern at this
moment must have been to obtain a satisfactory over-
all shape. Subsequently, presumably, Michelangelo would
have made measured drawings elaborating and clarifying
his clay model in preparation for the very large wooden
model, now in the Vatican, which marked the next major
stage in the preparatory process. Payments for this wooden
model run from November155 8until November 1561.
One of Michelangelo’s measured working drawings for it
survives in Florence (CB 31 A/B15 2/Corpus 600 ; pen and
brush and wash over black chalk, 388 × 555 mm), and the
dimensions of its forms are those of the corresponding
parts of the wooden model. In this drawing, Michelan-gelo was repeating his procedure in preparing the large
wooden model of the fac ̧ade of San Lorenzo, some forty
years earlier, for which he had also made same-size draw-
ings, in effect templates. As pointed out by Hirst ( 1988 ,
pp. 97 , 103 ), an outline drawing now divided into three
portions housed in Florence and London (it is found on
the versos of CB 71 A/ B 58 /Corpus 183 ,CB 49 A/B 59 /
Corpus 182 , and BM W 25 /Corpus 184 , with a combined
dimension approximately 500 × 220 mm maximum) was
made as a template for the twelve columns by which the
lower storey of the model is articulated.
The wooden model for St. Peter’s includes both the
drum and the dome, and it is noteworthy that CB 31 A,
which specifically prepares a section of this model’s drum,
differs in certain significant respects from the model as
executed. This requires emphasis because it is some-
times assumed that the structure of the drum was fully
determined by155 7.CB 31 A carries autograph explana-
tory inscriptions, presumably made for the carpenter,
and one of these specifies it as havingochi(i.e., circu-
lar, not rectangular) windows. Circular windows are also
seen in Michelangelo’s elevation drawing of the drum
and dome in the Mus ́ee des Beaux-Arts, Lille (Brejon
de Lavergn ́ee 107 /Corpus 595 ;black chalk over ruled
lines in stylus, with compass marks, 259 × 257 mm) (The
date of this drawing is much disputed but, among many
other features, the inscription on its verso referring to
the muleteer Pasquino, recorded in Michelangelo’s cor-
respondence only from mid-155 7 onwards, and a small
sketch of the stairway joining thericettoand reading room
of the Laurentian Library, a project under renewed con-
sideration in late155 8, strongly suggest a date of late155 8
for the whole sheet). The scheme in the Lille drawing,
with its drum containing circular windows, recalls the
drum of Brunelleschi’s Duomo in Florence. Although in
the wooden model for the drum and dome of St. Peter’s
as constructed, the drum is illuminated with upright rect-
angular pedimented windows on both interior and exte-
rior, it seems clear that as late as the beginning of work
on it in November155 8, Michelangeo was still uncer-
tain about the windows’ shape. They remained subject
to change: In the model the pediments surmounting the
windows are triangular on the exterior and segmental
on the interior; in the building there are alternating tri-
angular and segmental pediments on both interior and
exterior. A large drawing in Casa Buonarroti composed
of two sheets which Michelangelo first joined and later
divided (CB 124 Averso and CB 103 Averso/B 160 and
264 /Corpus 612 and 613 ;brush and wash over black
chalk, combined dimensions 617 ×37 6mm maximum),