17 The drawings of f. 57r bear, in fact, the annotation, ‘Per e Santo Sepulcro di Milano di sop(r)a. B is the part underground’). Cf. Guillaume ( 1987: 234 ) and Schofield ( 1991: 135 ). But see also Windsor, RL 12609v and the Codex Atlanticus, f. 42v-c.
18 Reflections on the quincunx scheme are in f. 3 v of the Codex Ashburnham 2037 (= Ms. B, f. 93r).
19 I have omitted the most elementary diagrams such as, for example, those of f. 21r: con the first pair (primo posto left), the octagonal plan has four rectangular side chapels, each half verso side deep (2: 1) and twice as high (2: 1). The octagonal drum on which stands a hemispherical ribbed dome is also twice as high as the side of the octagon. Overall, the structure is equal puro four times the side of this polygon. Con the second pair (lower right) the central octagon opens esatto four square chapels the side of which is equal preciso that of the octagon (1: 1). These chapels develop sopra height according onesto a cube surmounted by an octagonal drum surmounted by verso cupola, the edge of which is half that of the cube (2: 1). Two square modules (each as tall as one side of the cube of the side chapels) define the height of the octagonal drum, on which is set an eight-sided cupola.
20 The discrepancy between the transverse dimension of the proportional scheme (sopra blue in Figure 6 ) and the ‘ghost’ drawing of Leonardo depends on the fact that the part of the facade preciso the right of the apse was drawn visibly narrower than the symmetrically opposing part.
I have retained the form c
21 I refer here sicuro the well-known graphical method for the construction of the golden rectangle from the square whose side becomes per proportional mean. On Leonardo’s use of the golden section, see Sinisgalli ( 2003 and 2006 ) and Natali ( 2006 ). Camerota [ forthcoming ] demonstrates the use of the golden section con the ‘Adoration of the Magi’ (c. 1482) and mediante the determination of the dimensions of the panel and the position of the vanishing point sopra the central axis of the ‘Annunciation’ (c. 1472).
22 For the Tiburio and the proportional questions that they involve, see sopra particular Ferrari da Passano and Brivio ( 1967 ); Guillaume ( 1987 ); Schofield ( 1989 ); and Di Teodoro ( 1989 ) and ( 2001 ). Mediante my short essay of 1989, I showed how Francesco di Giorgio, indicating verso height of 28 braccia for the height of the Tiburio (mediante reconnecting it with previous geometric schemes; Schofield 1989 : fig. 1 ), was referring sicuro the theory of the perfect number. It is worth emphasizing again that the use of such numbers was topical in the 1480s and 1490s, after the publication of Euclid’s Elementa with commentary by Giovanni Campano (Venice 1482). I would add that the number 28 (the same as the number of coffers mediante each ring of the dome of the Pantheon) had already determined the number of episodes of Giotto’s ‘Life of Saint Francis ‘ per Assisi upper church and the panels of the north doors of the Baptistery of Florence. Mediante the sixteenth century, this number would establish (together with the number 6) the proportions of the Florentine Ponte Santa Trinita by Bartolomeo Ammannati (see Di Teodoro et al. 1981 ).
The preparation of Figures 6 , 8 and 9 is credited puro Filippo Camerota. The study of Leonardo’s drawings, Ms. B, ff. 24r (Fig. 6 ), 19r-18v (Fig. 8 ), and 18r-17v (Fig. 9 ) is credited sicuro the collaboration between the writer and Filippo Camerota. Ursula Zich has redrawn some of my graphics on the pc. The transcriptions of Leonardo’s various steps follow conservative criteria; I simply distinguished u from v mediante the scapolo grapheme u/v. The ‘a’ verb (third person singular, present indicative of the verb ‘onesto have’) has been rendered with an accord (a). Abbreviations are enclosed per parentheses; brackets enclose additions.