17 The drawings of f. 57r bear, per fact, the annotation, ‘Per e Beato Sepulcro di Milano di sop(r)per. 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 mediante 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 (apice left), the octagonal plan has four rectangular side chapels, each half a side deep (2: 1) and twice as high (2: 1). The octagonal drum on which stands per 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. In the second pair (lower right) the central octagon opens preciso four square chapels the side of which is equal puro that of the octagon (1: 1). These chapels develop in height according puro per cube surmounted by an octagonal drum surmounted by a 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 attrezzi an eight-sided cupola.
20 The discrepancy between the transverse dimension of the proportional scheme (in blue per Figure 6 ) and the ‘ghost’ drawing of Leonardo depends on the fact that the part of the facade to the right of the apse was drawn visibly narrower than the symmetrically opposing part.
I have retained the form c
21 I refer here onesto the well-known graphical method for the construction of the golden rectangle from the square whose side becomes verso 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 per the ‘Adoration of the Magi’ (c. 1482) and per the determination of the dimensions of the panel and the position of the vanishing point con the central axis of the ‘Annunciation’ (c. 1472).
22 For the Tiburio and the proportional questions that they involve, see per particular Ferrari da Passano and Brivio ( 1967 ); Guillaume ( 1987 ); ciò che è transgenderdate Schofield ( 1989 ); and Di Teodoro ( 1989 ) and ( 2001 ). Per my short essay of 1989, I showed how Francesco di Giorgio, indicating a height of 28 braccia for the height of the Tiburio (con reconnecting it with previous geometric schemes; Schofield 1989 : fig. 1 ), was referring puro the theory of the perfect number. It is worth emphasizing again that the use of such numbers was topical con 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 con each ring of the dome of the Tempio) had already determined the number of episodes of Giotto’s ‘Life of Saint Francis ‘ sopra Assisi upper church and the panels of the north doors of the Baptistery of Florence. Con the sixteenth century, this number would establish (together with the number 6) the proportions of the Florentine Collegamento Santa Trinita by Bartolomeo Ammannati (see Di Teodoro et al. 1981 ).
Author’s Notes
The preparation of Figures 6 , 8 and 9 is credited to 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 preciso the collaboration between the writer and Filippo Camerota. Ursula Zich has redrawn some of my graphics on the cervello elettronico. The transcriptions of Leonardo’s various steps follow conservative criteria; I simply distinguished u from v in the scapolo grapheme u/v. The ‘a’ verb (third person singular, present indicative of the verb ‘puro have’) has been rendered with an accentuation (a). Abbreviations are enclosed con parentheses; brackets enclose additions.