The first use of one-point perspective in intarsia, as we have discussed in A, is by Antonio Manetti, beginning in 1436, in the North wall of the North Sacristy in the Florence Cathedral. The influence of his work can be seen on the rest of the walls in the North Sacristy and then it expands from there to other centers of wood inlay production, including Urbino and Gubbio (analysed in C and D). Before we leave Florence for other towns, however, it is important to notice one more thing about Antonio Manetti's ingenious wood inlay illusion created for the Florentine Duomo:
The ledge seems to come towards the space of the viewer and extend out over the space in front of the faux brads which also give the illusion of projecting into space. All of it is in actuality flat, but Antonio Manetti manipulates the pieces of wood to make viewers think that if they reach out and touch, their hands will come first upon the wooden ledge and the hexagonal candleholder above it before reaching the open cabinet door, the shelf behind that, and the fringe of the curtain behind that. It is an astonishing illusion of five layers of depth made out of pieces of wood that all are inserted into a flat frame.
But the most remarkable thing about its creation is that Manetti is able to give the viewer not just the illusion of space receding into depth from the picture plane in the shape of cabinet shelves and objects on them, but the illusion of FORWARD SPACE, with objects that appear to project forward of the picture plane into the real space of the viewer. His ability to depict in wood inlay a ledge reflecting light from the candle above it and pushing into the space in front of all the cabinets and cabinet doors on the wall is unique for the period he is living in. I know of no other attempt to convey FORWARD SPACE in painting or wood inlay before this example. (Samuel Edgerton in his illuminating 2009 book, The Mirror, the Window, and the Telescope (Ithaca, Cornell), p. 8, describes this interest as "forward projection" but does not mention its use in intarsia.)
After Manetti's extraordinary demonstration of the use of one-point perspective to convey FORWARD SPACE, other artists become interested in the possibility. In the same room the artist Giuliano da Maiano who is responsible for the end (east) wall (1463-65) of the sacristy, inserts an intarsia figure of a saint into a faux niche and he can't resist showing the name banner of the saint extending forward into the viewer's space beyond the niche space conveyed in the intarsia:
Isaiah stands with left arm akimbo while his name banner cascades down from his hand "YSAYAS P." (Isaiah Prophet). The viewer looks up at him in the second register of the intarsia wall and Giuliano da Maiano shows the bottom of his shoes and the hem of his skirt from "sotto in su" (from below looking up) in accord with the actual view we would have of a real person in a real niche at that height.
Here the banner is unscrolled with "sprezzatura" (ease of handling) and the banner cloth resembles a shape that would have been familiar to intarsia artists, the curve of a wood shaving.
After the early precocious demonstrations in wood inlay of the possibilities of FORWARD SPACE, painters take up the cause. Andrea del Castagno is one painter who understands the skill required to convey this type of space and he displays his interest even before Giuliano da Maiano finishes his saint in the niche. In the Famous Men and Women series painted for Filippo Carducci's private villa in Legnaia between 1449 and 1450 Castagno applies the ideas about FORWARD SPACE that he could have learned from Antonio Manetti. A reconstructed view of how the villa series might have looked:
(There is very little left on the walls of the villa now and some of the figures are in Sant'Apollonia, some in the Uffizi.)
The famous men and women include people like Dante Alighieri, Petrarca, and Boccaccio, as well as military commanders and virtuous women. They stand singly in rectangular niches.
Castagno paints Dante with right hand holding one of his books and left hand gesturing outside the picture plane, the marble of the niche. His left foot is kept within the picture plane, but his right foot and bent knee are depicted forward of the niche's space. Castagno paints a shadow below the foot to highlight (literally) the projection of the foot, and the shadow falls on part of Dante's first name.
The figure of Pippo Spano, a condottiere, (leader with a private army) stands much like Donatello's St. George in his niche in Orsanmichele (1417), weight on both legs, but Pippo's left armored leg sticks out over the parapet of the niche and projects into FORWARD SPACE.
The women are depicted in much the same way by Castagno:
Since both the Cumaean sibyl and Isaiah were thought to have prophesied the virgin birth of Christ, the connection is more than just surface, as it were.